I'm new to this topic. I have a question. In the example of the moths. You know how before the industrial revolution trees were NOT black? How could then black moths survive before trees became black? they could have easily been spotted by birds and therefore would have been easily destroyed leaving only moths with white dots around. After the black moths were destroyed then Industrial revolution came and there were no black moths anymore therefore moths with white dots were destroyed .
@KingDcome11 Because that theory has been disproven. Birds don't observe based on color - rather, they see in a spectrum beyond human vision (UV as well I think). The moth wings are supposed to disrupt that UV vision and NOT color vision. It's an interesting paper.
@KingDcome11 You're generalizing. It depends on the ecological niche that the moth your talking about. If the predators depended on color spectrum light, then the moth would evolve defenses to camouflage them based on color. But if the predators saw in a different spectrum, then the moth would evolve defense to camouflage based on that. It all depends on what predators are around in that specific moth specie's environment.
I don't think we can assume that natural selection is the only form of evolution, there is much it doesn't explain; for example, why are humans losing their hair? Why are we losing our baby toes? Why are we losing our wisdom teeth and why are we losing our appendixes? It's not like the person without any of these is more adapted to their environment. Well the explanation is that genes do possess a mind - epigenetics.
Apes don't have tails, that's a monkey. The singular for bacteria is bacterium.
@CromlechDolmen get a life. he graduated from harvard, and people make some mistakes. he was only trying to relate to younger audiences when he even drew the picture. genes don't possess a mind; they're the things that make UP our mind. we're not losing our baby toes...whoever is has a mutation. we don't lose our wisdom teeth, we get them taken out. we don't lose our appendix; they become inflamed, having the need to be taken out.
@xoalaraxoxo@CromlechDolmen , we AREN'T losing our hair; perhaps from old age but that's due to the dying of cells. If you're talking about hair on our body, it's simply adapting to our environment. variation. if you go to the middle east or to mexico or spain, you'll see people are very hairy there. you need to get off your 50 year old trolling ass and stop trying to "correct" people with what you THINK is right, and do something productive with your life.
@xoalaraxoxo We are also losing our appendixes, a few tens of thousands of years ago they were a large extension of our caecum, now they have become vestigial organs sucking a few minutes of our life. Again our wisdom teeth may have been used for finely grinding fibrous foods such as leaves etc., our bodies recognise that they are no longer needed and many people never develop any during their lifetime.
@xoalaraxoxo Baldness, although affected by senescence, is a phenomenon they only some experience, thus, it is not directly related to old age and again is becoming more common as the human race develops. The simple explanation is that unused enzymes cease being manufactured and trigger chemicals to alter the structure of our genes; these alterations may travel through the generations and become more pronounced. By the way, I'm not 50 I'm 19 - how embarrassing for you!
@xoalaraxoxo Am I supposed to be impressed by the fact that he holds a Harvard degree in business? How does that have any bearing on how much he knows about genetics? I bet I know more on the subject than he does anyway. People may make mistakes, but I assure you I am no ordinary person; I have made no mistakes on my original comment. I can't explain all on one YouTube post but rest assured, the human race is indeed losing their fifth toe, within a few million years it will be gone
A very good video, but some minor points are wrong: "natural selection" is not a different name for Evolution, but rather one of its components. Also, in the moths example, by your drawings there is a flawed logic: if the trunk looked like that before the revolution, the dotted moths would be selected and preferred by natural selection already. I understand that a change from one dominance happened to another, but the detail can be confusing.
So your channel covers Biology,Chemistry, Physics, Maths, History etc. I've always waited for an Art section, but I now see why you've chosen to leave that subject out ;)
One would think creationists would be jumping behind evolution; if it turns out that God created the elements and the physical rules, and let everything spontaneously occur, then at least God would be off the hook for clumsy, far-from-intelligent designs such as autoimmune diseases and coagulation disorders; because if an omnipotent being designed those doozies, it must have been done during a heavy night of drinking.
Hear what God of Israel YAHUSHUA-YAHUWAH (Son and Father are ONE) saying to our generation by His chosen prophets: Trumpetcallofgodonline. com ; Letter called "Purify Your Faith, and Come to the Father as It is Written": EXCERPT: "Only in the Bible and through these very Letters, of which I have given to My prophet of the end of this age, shall you find Him and know Him."
I can't stop laughing! the site's goal is stated as 'aimed at providing world class education' and here the guy is drawing hats on monkeys, and saying "this dude" and "that dude" every other sentence. PROFESSIONALS AT WORK, GUYS!
I don't see you doing a better job than khan academy ,plus I don't see anything wrong with saying "this dude" or "that dude" if that will make the student understand the subject.
Why wouldn't it qualify as an argument many teachers use whatever they have in their toolbox in order to explain a idea its much better than being overly formal and noone would understand anything.
@GenericCoder you made it clear that you think i was on the standpoint of mocking their approach, *whispers intimately into your ear* which i never did...
Khan Academy now has significant backing from the Bill Gates Foundation and Google.Yet every day I search on Wikipedia, I see a large banner asking for donations or else they threaten us with advertisements. If Bill Gates funds Sal and Sal uses Wikipedia, wouldn't it make sense for Gates to fund Wikipedia? Wikipedia: "If everyone reading this donated $5, we would only have to fundraise for one day a year." Bill has the $ so that wiki stops bombarding the middle class.
@EnlightenedReader An essential, well documented and easily observable, change in form. I understand the unfairness of it, a man of science must provide and immeadiate and comprehensive answer to any question asked, and if he cannot, the alternative is true by default. I see it as a spin-off of affirming the consequent, if not a, then b.
@DomeSwag Untrue, an answer need not be provided immediately, a question may be answered after evidence is acquired. And the "if not a, then b" statement is ridiculous, no proposition to a question can be automatically accepted without scientific evidence. Case and point Pastafarianism.
That's a false dichotomy. There's several creation stories and some of them are inconsistent with evolution. So all of them are correct, even if they are contradicting each other, just because evolution is wrong (which it hasn't been shown to be)?
Even IF evolution was proven wrong that doesn't make ID or creationism correct, because they still have to prove their own assertion before it can be taken in as a theory.
@EnlightenedReader Really needs to be a non-phenotypical change. Many/most creationists have accepted (only due to a mountain of evidence) that simple phenotypic changes are entirely possible, but no 'real' changes can come about.
Can anyone think of relevant examples, in real time, where natural selection is displayed? I see it in Sickle Cell Anemia and Staph's resistance to antibiotics. Are there more examples?
@DomeSwag The ability to drink milk without getting sick (lactase persistence). This actually evolved 3 separate times within the last few thousand years in response to the domestication of cattle. Most people in the world actually can't drink milk without feeling sick. Drinking milk is the minority and it's thanks to natural selection.
@Simplistified "Better" only depends on the context which you exist. It's better to be black in Africa because of the amount of direct sunlight you get can damage your skin. It's better to be light skin in the Arctic because it allows more sunlight in to synthesize vitamin D. So there's no single answer for "better". This is the reason why people have different skin colors in the first place; it's in response to the sun's intensity.
Just a random thought; if humans are the result of natural selection from apes, why do apes still exist, and not things that are halfway between humans and apes? I'm not questioning your explanation, I was just wondering.
@InflatiblePalmTree because natural selections never affects every single being in a species exactly the same way. If that was the case there wouldn't be any, bacterias, amoebas, fishes etc in this world. Some apes exist because they didn't have to evolve to become more like humans, most prehuman species though are actually extinct. Which takes us to your next question.
There are a lot of things that are halfway between humans and apes. Most of them are extinct but their remains are found.
@InflatiblePalmTree An important thing i think you're missing: To say humans evolved from apes doesn't mean we can pick a chimpanzee out of the forest and say they are our ancestors. They are not. BOTH chimpanzees and humans are descendents of yet another (extinct) ancient ape that was different than both species. All species change over time (some more than others), and when two populations become separated they can BOTH change enough to be very different down the line.
@InflatiblePalmTree two things: Humans didn't evolve from apes. We share a common ancestor with apes. It looked more like an ape than a human, but it wasn't the apes we see today. Second, our ancestors took many different evolutionary paths. A group gets isolated from the rest of the population and takes a different evolutionary path.
@InflatiblePalmTree Modern apes, the "apes" we know today, are not what humans evolved from. Humans and apes simply share a common ancestor - humans and apes both evolved from another creature, one which closely resembled apes.
Khan makes a lot of general assumptions most of which are completely unproved and unsubstantiated. He over simplifies the real issues to make evolution "acceptable". Although he states progression from ape to man as a fact, there's still no definitive evidence of this and absolutely no supporting fossil record. He simply avoids where the original "design" came from and the "info" that was coded in the DNA to make this possible. He again presupposes that the original design just happened.
@DaddyDAJ yes, there are fossil records. you are going to say there's gotta be more. fossil first of all are extremely rare, but we do have fossil records and genetic evidence. not only on primates to men but other animals as well.
your "original design" isnt evolution, it's a study called abiogenesis (inorganic chem to organic chem to self replicating chem). evolution is the study of change, from simplicity to complexity, a study of adaptations
I called you an idiot because your belief is "is just a gut feeling, or insecurity and need for reason of crap that happens." You typed that, didn't you? I can't respect anyone who thinks like that.
@khanacademy Isnt it amazing how far our brains evolved? It passed the point of basic survival and "need" to the point where we cant ever reach the maximum capacity or potential of our brains. Not to be religious(i dont support any one religion), but that is a pretty good prove of a creator or intelligent design.
If you see this post elsewhere, its probably me feeling the need to share this epiphany. =|
@notfree25 firstly, there are 3 types of natural selection, there is an narrowing in variation, a shift in traits, and a split effect. so let me explain this, our brains are an example of narrowing variation, the brain and the nervous system evolved to keep balance, just imagine a person that trips 2 or 3 times while chasing animals or running from predators, he wouldn't survive for long, then there came the problem of walking upright, which is economical(in energy) but not fast. I ran out of ch
@notfree25 Well I am an evolutionary biologist, so let me be the first to tell you what you said is absolute hogwash. There is absolutely no evidence that supports "intelligent design" (you might as well label that pathetic term creationism) and it hurts to see people flailing their ignorance in a subject they know little about
@karim3343 seriously? do you guys see the word religion and decide that you have to argue?
How is spirituality any different from unproven theory? Last i heard, multiverse still has no conclusive proff and physicists swear by it. Are you calling them idiots too?
Here is a new word you to to learn today. "Verificationism". Bye
@notfree25 First of all "spirituality" is not a theory. Secondly, the Multiverse is hypothetical. Physicists do not "swear by it", or else yes those particular physicists that you speak of should be labeled as distorting science with pseudoscience. Please do not try to claim that the Multiverse scenarios (of which there are 6-7 different versions, all understood to be mathematically possible in general scientific consensus) with that of "spirituality" which has no theory or conjecture. Thanks
@notfree25 Thank you for bringing up "Verificationism". For your information, Verificationism is the view that a statement or question is only legitimate if there is some way to determine whether the statement is true or false, meaning your belief that Spirituality is existent in this universe, cannot be proved or disproved, thus should be discounted completely as not worth having a conversation over.
@notfree25 I would like to agree to disagree, and leave it at that, but unfortunately what you are saying is incorrect. Physicists do not "believe" in the Multiverse, they have Mathematical theorems that provide for additional universes. Spirituality claims in itself to be unproven. It is so special that you can't prove it with Scientific conjecture. That is the whole point of spirituality. What good would it do if you could measure it? It would not give it that extra appeal if you could.
@notfree25n Not at all, there are many ways to explain these fundamental results. Extra dimensions, Many-worlds interpretation, etc. But these all center on the "different realms" if you will, of "things". The fact that this is not the only explanation means that it is not a given law. Physicists just say, "oh look, there is no Scientific law that goes against a Multiverse theory. Oh and look, a lot of these postulations work towards a Multiverse. Therefore it's certainly probable" That is it.
@karim3343 i would leave it at that but hey, this conversation is getting kinda interesting. Also im an ass.
Can we go with "Oh look, there is (still) no way to disprove sprituality. Oh and look, weird stuff is happening that no one can explain. Lets call it supernatural and "a greater beyond" ".
@notfree25 First of all, Multiverse theories are explained very precisely. The only reason there is still ambiguity about them is because there is no way (yet) to test these hypotheses. With Spirituality there isn't even a theory, not even a conjecture or guess. I reason that this is where you input your "Oh and look, weird stuff is happening that no one can explain" Please state the "weird stuff. no one can explain" (there is a difference between something we cant explain yet and miracle stuff)
@karim3343 Honestly, mine is just a gut feeling, or insecurity and need for reason of crap that happens. I dunno, im not a physiologist, im a tech student. * shrug*.
Have you ever meditated? Your a biologist right? could you explain that tingly feeling i get on my forehead when i place things near it, or when i focus/meditate on it, "miraculous recovery of terminally ill patients"? placebo effects and "power of the mind/belief"?
Maybe my interpretation of spirituality is loose. Also out or cha..
@notfree25 I am sorry but you would have to be much more specific than just hearsay and social perceptiveness of these events. Could you give me a particular event that is actually so awe aspiring as to have not only no explanation, but also an understanding that we will never have an explanation? Those are two very very different things. There is already an understanding of how placebo effects work, "power of the mind/belief" just sounds so generalized.
@notfree25 Sure ok. There have been many studies concerning the placebo effect. We know how it works, but understand the brain is still extremely complex, and to characterize all the hundreds of billions of inter-neural connections and protein functions will take more time (1-2 decades). But many processes that occur during placebo medications have already been categorized. Your genetics largely dictate whether you are more prone to the effect.....
@notfree25 The brain has control over the body processes affected by placebos. Pain, motor fatigue, and fever are directly organized by the brain. Other processes usually regulated by the body such as the immune system are also controlled indirectly through the sympathetic and parasympathetic nervous system.
@karim3343 ok fine, belief has no use whatsoever. Genetics and things that we still need to further study does.
i could ask about the birth of the first single cell, or the universe itself, but it could be explained away with chance occurrence. There is no larger meaning to life than an effect of your parents reproducing. Why does wave travel the way it does? It just does. Why does light travel at so fast? it just can.
imma stick with science and spiritualism can still compliment each other.
@notfree25 I'm not saying people can't be spiritual, I am just saying that spirituality does not correlate with Science whatsoever. Spirituality has no Scientific meaning although I do believe it can help with someones life. As for the universe or first cell, that has nothing to do with chance, and your questions about waves and light are very childish. Of course we can explain why they do the things they do, but your real question is just, "Why?"
The condition at the moment was just right for a single cell to appear into existence? that would be chance. If conditions were different, would the organism had evolve to breath other gases?
new thought, are new single cells coming into existence even now?
Science is digging into the universe for explanations... what are you saying? we can stop if your getting agitated.
@notfree25 Your arrogance on this topic in enormous. Unless you have a degree in this area I suggest you stop asking mundane questions with such arrogance and aptitude. Firstly, Evolution occurs from natural selection, almost 100 percent of scientists agree on that, so for you to propose otherwise is of immense ignorance. Secondly, open your mind. There is no right condition for life. Life can occur and survive at the most extreme and strangest places. Yellowstone’s Hot Springs, (continued)
@notfree25 In bodies below the freezing point of water, entirely alone, The Galapagos Islands, Acidic Mine Drainage, Deep Sea Vents, in the coldest places on Earth, In the Stratosphere (Yes, the stratosphere—the layer of Earth’s atmosphere that starts at about six miles above the ground), we even have revived much older spores of bacteria from 250 million years ago... That is just our own planet. There could be life in other more "inhospitable terrain" on other planets (continued)
@notfree25 Species that could be silicon based, or from some other exotic material. "Evolution is chance and probability" Again ridiculous assertion. Through natural selection those that reproduce more are usually those that live long enough to reproduce. They live long enough because of their more impressive characteristics in comparison to their environment (as opposed to another subspecies of the same animal which is weaker or has lesser traits etc.) This happening over millions of years has
@notfree25 absolutely nothing to do with luck. May I ask your expertise in the subject because it seems to be lacking... "Evolution is chance and probability" I do not understand how you have the audacity to tell me this. I have been an evolutionary biologist for 6 years and studied at MIT and Harvard. I do not need you to arrogantly state to me inaccuracies. Being ignorant about something is one thing, being arrogant AND ignorant about it is another. You are telling me all the evidence (cont)
@notfree25 (cont) we have over the hundreds of millions of years, and the last 3 centuries we have been collecting it, and that all the great scientists, like Charles Darwin, Richard Dawkins, PZ Meyers, etc. simply don't mean anything? Quantum Mechanics explains the origins of the Universe, and this explains the biological component. There is no question among Scientists, all of your misinterpreted pseudo-scientifc beliefs are not of any meritable discussion.
yea, thats their condition. and they formed into a life form that strives in such condition. I never said the surface of the earth was the only right condition.
Im saying it was chance that life formed. Are you saying nothing is to chance? Why isnt new species forming in your toiletbowl?
It was your arrogance that made you reply to each of my comment. Not mine. Like i said, im having fun. I also told you honestly, Im a tech student. U mad. Lets stop
@notfree25 In conclusion, Evolution is a fact. As I said there is no meritable discussion here that will change that. Your questions can all be answered in basic Biology course. See how much you understand in a Semester. I don't know how you went from asking is the formation of life just luck and chance, to now asking "Are you saying nothing is to chance?" Its very incoherent. Also, yes new species are forming out of "nothing", Its called Speciation. We can do it artifically in a lab as well.
@notfree25 Evolution is not chance and probability, it's the exact opposite. Natural selection selects useful traits which aid survival, which is non-random.
@notfree25 That's a good question. I don't actually know the answer. I was told all life started out as a bacterium (one bacteria) that began to replicate, and eventually formed modern cells, but I'm not sure.
"What i meant was why didnt other single cells form (not from Speciation, but formed) from non-living materials, like that first single cell did."
That appears to be the case.
Bacteria and Eukaryota don't share basic features in common that one might expect and it's unclear whether Archaea are an early branching of Eukaryota or a separate Kingdom.
Organisms compete... It wouldn't be terribly surprising if entire kingdoms had become extinct during early abiogenisis.
And to answer that, do you think the universe owes you an explanation? Just because you are one being of 7 billion on planet in a solar system in a Galaxy of 100 billion planets, of 100 billion galaxies, that is evolved from a primate, over only the last 250,000 years. Do you really think that the universe owes you an explanation?
@notfree25 And to answer that, do you think the universe owes you an explanation? Just because you are one being of 7 billion on a planet in a solar system in a Galaxy of 100 billion planets, of 100 billion galaxies, that is evolved from a primate, over only the last 250,000 years. Do you really think that the universe owes you an explanation?
@notfree25 Well I'm no expert on this. But I'll try to explain my thoughts in 500.
Humanoids walked on 2 legs before they developed big brains. This causes a disadvantage for them. The humanoids that were smarter lived long enough to pass their genes. Working in groups proved as an advantage as well, so humanoids with good social skills had a better chance of being selected. Once social structures are in place things can get really complex and more advanced brains are favoured.
This was one of the first videos I've watched from the Khan Academy. Now, 4 months and almost 1100 videos later, I came back to this. What the Khan Academy has done for me is amazing, the amount of things I've learned is more than my whole high school experience. Sal Khan is my biggest inspiration and his work is truly amazing. Thank you for teaching the world.
only critisism I have is that the black moth characteristic was important even before since the industrial revolution simply because there rate of survival was affected before it hence the smaller numbers that they have had.
Our Lord Jesus Christ is not an animal , in fact he made animals just like people too.. He made all thins so how's that ?? i'm human and i'm not an animal .. God created me and God is not an animal !
Our Lord Jesus Christ is not an animal , in fact he made animal just like people too.. He made all thins so how's that ?? i'm human and i'm not an animal .. God created me and God is not an animal !
@MsNica002 It is not a good idea to take creation stories literally when it comes to science. You were created by your parents, so in biological terms you're an animal like all humans. This is not a bad thing (it's actually kind of cool). All life comes from evolution and it's a completely natural process. That's why there are such harmful things like viruses and bacteria and parasites. They are formed by natural processes. No God would create harmful things like those right?
@MsNica002 You are an Animal. We are all animals. Prove that we are not animals. We have all the functions of an animal, apart from the fact that we are of greater intelligence.
@MsNica002 This comment is just arrogance, it seems you have no place for new discovery because of you religion. I'm a Christian, i still believe in natural selection because i'm open to new things.
@waksibra No, monkeys have tails and are not as smart as apes. Apes are Chimpanzees, Binobos, Gorillas, & Orangutans and are extremely intelligent, second or third in the world. Humans are first, Dolphins may be second, it's debatable.
@Stevesrssrssrs I've learnt that apes are monkeys because apes evolved from monkeys in the same way birds evolved from dinosaurs. But, yes, people use different terminology.
wouldn't the peppered moths that weren't "as peppered" get hunted to extinction before the industrial revolution came around coz they would be easier to see without as many spots. not a great example iyam.
Good point. The answer is perhaps that the 'unpepperedness' was a novel mutation at the time of industrial revolution. What would have been a harmful freak mutation in other times, became a very useful one in industrial environment. The rules of the game change as the environment changes. The same genes for craving sweets that made our ancestors survive, are now killing us by millions.
Awesome videos! Just one little detail: in this video at about 17:20 you make a claim that seems to suggest how the selection itself is also random. No big deal, and i mention it only because it is often how creationists "understand" it and then start arguing that the complexities observed could not have arisen out of pure chance. If selection was random, they'd be right-- but of course we know that selection is everything but random. The very word gives a hint after all. Keep up the great job.
Natural selection is only one of the forces that can cause evolution. You forgot to mention mutation, genetic drift, and gene flow. And related to natural selection is sexual selection.
@QPEY07 you are an ape and you have a tail bone. thats what youc coccyx is. you actually have the genetic instructions for making a tail, they are just never manifested... well.. they are sometimes. sometimes a baby is born with a tail. its a genetic mistake that accidentally expresses those genes that are responsible for making tails.
its called a "vestigial organ". we see it all around nature. if you are a creationist idiot, its all the proof you need that evolution is true.
@volound yes, there has been observed instances of evolution, but you make the very common mistake of convoluting macro-evolution with micro-evolution. Micro-evolution is extremely common and is attributed to the natural adaptability of a species. However, the change of a genetic code from one species to a completely new species (i.e. macro-evolution) has never been observed and lacks a sufficient mechanism to acheive it (no, mutation is not a sufficient mechanism).
@volound Also, speciation is more of a byproduct of our naming conventions than it is proof of evolution. We could say the chihuahua and the great dane are two different species, but really they are both variations of a dog. The problems with naming of species and speciation is really a different topic.
@Threnodist1 natural selection is the mechanism. natural selection is the process wherein the environment favours attributes (which are sympyomatic of genes) more than other attributes. this results in variations in allelle frequencies which accumulate. enough accumulations (time and environmental change) results in speciation.
each human today inherits approximately 100 mutations. thats only ONE generation.
im curious, do you acknowledge the chihuahua and great dane come from the wolf?
@volound Natural selection competes traits that are already existant in a species. In the peppered moth example, there were already dark and light moths. Natural selection merely dictated which would thrive; it did not create the light or dark moth. And yes, I would acknowledge the shared ancestry of the two dogs (though i can't be sure of their common ancestor). The genetic potential for large and small existed in their common ancestor. Husbandry selected it. Not evolution.
@Threnodist1 "Natural selection competes traits that are already existant in a species."
so how do you hope to account for the myriad examples i could give you right now that are obviously not? this is absurd. traits are lost and gained in their dozens/hundreds every single time an organism is conceived. this is one of the most absurd things i have ever read.
"The genetic potential for large and small existed in their common ancestor."
the genetic potential for ANYTHING exists in ALL genomes
@volound New traits are never gained. Only lost. I can always lose information. i can never create new (in a naturalist environment). Mutations are either natural variations of the source genome or corruptions that result in deformity. Compare controlled fruit flies and fruit flies with artificially mutated genes, and the normal are the "fitter" every time.
"the genetic potential for ANYTHING exists in ALL genomes"
False. A mosquito will never birth a fly or a horse or a frog or a human.
and now there would be no more moths at all. I hope you understood my question.
KingDcome11 1 week ago
I'm new to this topic. I have a question. In the example of the moths. You know how before the industrial revolution trees were NOT black? How could then black moths survive before trees became black? they could have easily been spotted by birds and therefore would have been easily destroyed leaving only moths with white dots around. After the black moths were destroyed then Industrial revolution came and there were no black moths anymore therefore moths with white dots were destroyed .
KingDcome11 1 week ago 2
@KingDcome11 Because that theory has been disproven. Birds don't observe based on color - rather, they see in a spectrum beyond human vision (UV as well I think). The moth wings are supposed to disrupt that UV vision and NOT color vision. It's an interesting paper.
Gilgamesh417 6 days ago
@Gilgamesh417 So a moths surviving has never been based on their color?
KingDcome11 6 days ago
@KingDcome11 You're generalizing. It depends on the ecological niche that the moth your talking about. If the predators depended on color spectrum light, then the moth would evolve defenses to camouflage them based on color. But if the predators saw in a different spectrum, then the moth would evolve defense to camouflage based on that. It all depends on what predators are around in that specific moth specie's environment.
Gilgamesh417 6 days ago
I don't think we can assume that natural selection is the only form of evolution, there is much it doesn't explain; for example, why are humans losing their hair? Why are we losing our baby toes? Why are we losing our wisdom teeth and why are we losing our appendixes? It's not like the person without any of these is more adapted to their environment. Well the explanation is that genes do possess a mind - epigenetics.
Apes don't have tails, that's a monkey. The singular for bacteria is bacterium.
CromlechDolmen 2 weeks ago
@CromlechDolmen get a life. he graduated from harvard, and people make some mistakes. he was only trying to relate to younger audiences when he even drew the picture. genes don't possess a mind; they're the things that make UP our mind. we're not losing our baby toes...whoever is has a mutation. we don't lose our wisdom teeth, we get them taken out. we don't lose our appendix; they become inflamed, having the need to be taken out.
xoalaraxoxo 1 week ago
@xoalaraxoxo @CromlechDolmen , we AREN'T losing our hair; perhaps from old age but that's due to the dying of cells. If you're talking about hair on our body, it's simply adapting to our environment. variation. if you go to the middle east or to mexico or spain, you'll see people are very hairy there. you need to get off your 50 year old trolling ass and stop trying to "correct" people with what you THINK is right, and do something productive with your life.
xoalaraxoxo 1 week ago
@xoalaraxoxo We are also losing our appendixes, a few tens of thousands of years ago they were a large extension of our caecum, now they have become vestigial organs sucking a few minutes of our life. Again our wisdom teeth may have been used for finely grinding fibrous foods such as leaves etc., our bodies recognise that they are no longer needed and many people never develop any during their lifetime.
CromlechDolmen 1 week ago
@xoalaraxoxo Baldness, although affected by senescence, is a phenomenon they only some experience, thus, it is not directly related to old age and again is becoming more common as the human race develops. The simple explanation is that unused enzymes cease being manufactured and trigger chemicals to alter the structure of our genes; these alterations may travel through the generations and become more pronounced. By the way, I'm not 50 I'm 19 - how embarrassing for you!
CromlechDolmen 1 week ago
@xoalaraxoxo Am I supposed to be impressed by the fact that he holds a Harvard degree in business? How does that have any bearing on how much he knows about genetics? I bet I know more on the subject than he does anyway. People may make mistakes, but I assure you I am no ordinary person; I have made no mistakes on my original comment. I can't explain all on one YouTube post but rest assured, the human race is indeed losing their fifth toe, within a few million years it will be gone
CromlechDolmen 1 week ago
It's a good thing to be black!!! 07:43
mohtadi52 2 weeks ago
why can't my teachers be like you
jblack222able 3 weeks ago
You sir, are the best teacher that ever walked the planet :)
nexify1 3 weeks ago
WOW. What a great ending of a two thousand videos. Way to go till the MAN!!!!
makbadwan 3 weeks ago
eliminate the tail!!!
sonicheroin 3 weeks ago in playlist Biology
Natural selection is actually one of the easiest things I have ever seen! After thinking about it you ask yourself " this is so obvious! !"
INMATE2468 3 weeks ago
A very good video, but some minor points are wrong: "natural selection" is not a different name for Evolution, but rather one of its components. Also, in the moths example, by your drawings there is a flawed logic: if the trunk looked like that before the revolution, the dotted moths would be selected and preferred by natural selection already. I understand that a change from one dominance happened to another, but the detail can be confusing.
edilsoncr1 4 weeks ago
'willy-nilly' hahahahaa
boxerek123 1 month ago
You need to label these videos better so I can follow them in order.
briangunn21 1 month ago
@briangunn21 You can follow a more linear order at the website.
edilsoncr1 4 weeks ago
that was a great video
mikeeg96 1 month ago
what program did u use to draw this??
ArTZaKalnw 1 month ago in playlist Biology
@ArTZaKalnw
im sure he used paint
bevon17 4 weeks ago
So you are saying if I am black, I will have more sex? Get me a can of spray paint quick!
sethboy66 1 month ago
what if the moths get selected to eat the birds???
Ultbeastman 1 month ago
@Ultbeastman Then they would eat birds...
sethboy66 1 month ago
I think sal might have started the "arrow to the knee"
Ultbeastman 1 month ago
So your channel covers Biology,Chemistry, Physics, Maths, History etc. I've always waited for an Art section, but I now see why you've chosen to leave that subject out ;)
FilmFanatic94 1 month ago
@FilmFanatic94 its an academic channel I think, just finished watching the american history, that was very good.
thecrazybhanu 1 month ago
One would think creationists would be jumping behind evolution; if it turns out that God created the elements and the physical rules, and let everything spontaneously occur, then at least God would be off the hook for clumsy, far-from-intelligent designs such as autoimmune diseases and coagulation disorders; because if an omnipotent being designed those doozies, it must have been done during a heavy night of drinking.
hexokinice 1 month ago
"wow these moths are geniuses" XD that is too damn funny
Jue35Jue 1 month ago
Hey Sal are you entering Education: King of the Web I think you would do very well!
Chrisberg1996 2 months ago
This has been flagged as spam show
Hear what God of Israel YAHUSHUA-YAHUWAH (Son and Father are ONE) saying to our generation by His chosen prophets: Trumpetcallofgodonline. com ; Letter called "Purify Your Faith, and Come to the Father as It is Written": EXCERPT: "Only in the Bible and through these very Letters, of which I have given to My prophet of the end of this age, shall you find Him and know Him."
Watch:
"youtube.com/watch?v=INH-lNUQQZg"
"youtube.com/watch?v=lutJYDxP6ys"
"youtube.com/watch?v=R9ike7PKd8U"
Regards.
TrumpetCallofGodLT 2 months ago
I can't stop laughing! the site's goal is stated as 'aimed at providing world class education' and here the guy is drawing hats on monkeys, and saying "this dude" and "that dude" every other sentence. PROFESSIONALS AT WORK, GUYS!
i love this!
Nazareadain 2 months ago
@Nazareadain It's ok to have a bit of fun when you've got the intelligence to back it up.
Discern4 2 months ago 2
@Discern4 as opposed to when you're stupid - then it's just plain wrong!
Nazareadain 2 months ago
@Nazareadain
I don't understand your point.
infidelguy 1 month ago
@Nazareadain
I don't see you doing a better job than khan academy ,plus I don't see anything wrong with saying "this dude" or "that dude" if that will make the student understand the subject.
GenericCoder 1 month ago
@GenericCoder does that qualify as an argument where you're from?
Nazareadain 1 month ago
@Nazareadain
Why wouldn't it qualify as an argument many teachers use whatever they have in their toolbox in order to explain a idea its much better than being overly formal and noone would understand anything.
I hope I made my point clear now :).
GenericCoder 1 month ago
@GenericCoder you made it clear that you think i was on the standpoint of mocking their approach, *whispers intimately into your ear* which i never did...
Nazareadain 1 month ago
Natural Selection; The people Chuck Norris decides not to kill! Period.
ACoustaDC 2 months ago
Khan Academy now has significant backing from the Bill Gates Foundation and Google.Yet every day I search on Wikipedia, I see a large banner asking for donations or else they threaten us with advertisements. If Bill Gates funds Sal and Sal uses Wikipedia, wouldn't it make sense for Gates to fund Wikipedia? Wikipedia: "If everyone reading this donated $5, we would only have to fundraise for one day a year." Bill has the $ so that wiki stops bombarding the middle class.
Thumbs up if you agree!!
jumb0mumb0 2 months ago
@jumb0mumb0 Makes sense;email bill gates and the CEO of wikipedia
Ilikemeows 2 months ago in playlist Biology
@Ilikemeows
Thanks!
jumb0mumb0 2 months ago
@jumb0mumb0 The amazing wonderful thing is that they are independent of the higher class.
edilsoncr1 4 weeks ago
so we must change the word " creations" to " mutations" !?
dreamer12021 2 months ago
@EnlightenedReader An essential, well documented and easily observable, change in form. I understand the unfairness of it, a man of science must provide and immeadiate and comprehensive answer to any question asked, and if he cannot, the alternative is true by default. I see it as a spin-off of affirming the consequent, if not a, then b.
DomeSwag 2 months ago
@DomeSwag Untrue, an answer need not be provided immediately, a question may be answered after evidence is acquired. And the "if not a, then b" statement is ridiculous, no proposition to a question can be automatically accepted without scientific evidence. Case and point Pastafarianism.
TheFearUnlimited 2 months ago
@TheFearUnlimited ... unfuckingbelievable how dense the smart kids on the internet can be.
DomeSwag 2 months ago
@DomeSwag Bull-fucking-shit.
That's a false dichotomy. There's several creation stories and some of them are inconsistent with evolution. So all of them are correct, even if they are contradicting each other, just because evolution is wrong (which it hasn't been shown to be)?
Even IF evolution was proven wrong that doesn't make ID or creationism correct, because they still have to prove their own assertion before it can be taken in as a theory.
You're advocating ignorance you monkey.
Squiglypig 2 months ago
@EnlightenedReader And you totally just gave the example which I obviously just saw in the video, lol.
DomeSwag 2 months ago
@EnlightenedReader Really needs to be a non-phenotypical change. Many/most creationists have accepted (only due to a mountain of evidence) that simple phenotypic changes are entirely possible, but no 'real' changes can come about.
DomeSwag 2 months ago
Can anyone think of relevant examples, in real time, where natural selection is displayed? I see it in Sickle Cell Anemia and Staph's resistance to antibiotics. Are there more examples?
DomeSwag 2 months ago
@DomeSwag The ability to drink milk without getting sick (lactase persistence). This actually evolved 3 separate times within the last few thousand years in response to the domestication of cattle. Most people in the world actually can't drink milk without feeling sick. Drinking milk is the minority and it's thanks to natural selection.
vicksoma 2 months ago
@DomeSwag Evolution of HIV can be seen very easily as it occurs in a very short period of time.
TheFearUnlimited 2 months ago
is it better to be black?
Simplistified 2 months ago
This has been flagged as spam show
@Simplistified
"is it better to be black?"
In an environment where it is an advantage... yes.
Dark skinned humans are better protected from damage by UV light.
BUT
In environments where there is less sunlight, that also inhibits the skin's ability to produce Vit D.
So, the traits that are an advantage in one environment can actually be a disadvantage in another.
DeathofSpeech 2 months ago
@Simplistified "Better" only depends on the context which you exist. It's better to be black in Africa because of the amount of direct sunlight you get can damage your skin. It's better to be light skin in the Arctic because it allows more sunlight in to synthesize vitamin D. So there's no single answer for "better". This is the reason why people have different skin colors in the first place; it's in response to the sun's intensity.
vicksoma 2 months ago
you had me at "and maybe he also had a hat"
fancybelizabeth 2 months ago 47
ok so, overtime, we have developed many characteristics. we have developed many ways to live. -alysha 3rd,Biology
LATINA210MAMMII 2 months ago in playlist Evolution and biological Change
Just a random thought; if humans are the result of natural selection from apes, why do apes still exist, and not things that are halfway between humans and apes? I'm not questioning your explanation, I was just wondering.
InflatiblePalmTree 2 months ago
@InflatiblePalmTree because natural selections never affects every single being in a species exactly the same way. If that was the case there wouldn't be any, bacterias, amoebas, fishes etc in this world. Some apes exist because they didn't have to evolve to become more like humans, most prehuman species though are actually extinct. Which takes us to your next question.
There are a lot of things that are halfway between humans and apes. Most of them are extinct but their remains are found.
eddiemc7 2 months ago
@InflatiblePalmTree An important thing i think you're missing: To say humans evolved from apes doesn't mean we can pick a chimpanzee out of the forest and say they are our ancestors. They are not. BOTH chimpanzees and humans are descendents of yet another (extinct) ancient ape that was different than both species. All species change over time (some more than others), and when two populations become separated they can BOTH change enough to be very different down the line.
vicksoma 2 months ago 24
@InflatiblePalmTree two things: Humans didn't evolve from apes. We share a common ancestor with apes. It looked more like an ape than a human, but it wasn't the apes we see today. Second, our ancestors took many different evolutionary paths. A group gets isolated from the rest of the population and takes a different evolutionary path.
Jonmad17 2 months ago
@InflatiblePalmTree Modern apes, the "apes" we know today, are not what humans evolved from. Humans and apes simply share a common ancestor - humans and apes both evolved from another creature, one which closely resembled apes.
Task5003 2 months ago
@filmlovingmaniac thnx 4 d help :)
CSIR999 2 months ago
"...And maybe he also has a hat."
Oh god, I love you Sal.
Zitozu 2 months ago
Khan makes a lot of general assumptions most of which are completely unproved and unsubstantiated. He over simplifies the real issues to make evolution "acceptable". Although he states progression from ape to man as a fact, there's still no definitive evidence of this and absolutely no supporting fossil record. He simply avoids where the original "design" came from and the "info" that was coded in the DNA to make this possible. He again presupposes that the original design just happened.
DaddyDAJ 3 months ago in playlist Biology
@DaddyDAJ yes, there are fossil records. you are going to say there's gotta be more. fossil first of all are extremely rare, but we do have fossil records and genetic evidence. not only on primates to men but other animals as well.
your "original design" isnt evolution, it's a study called abiogenesis (inorganic chem to organic chem to self replicating chem). evolution is the study of change, from simplicity to complexity, a study of adaptations
filmlovingmaniac 3 months ago
10:14 omfg we evolved into aliens by the flu!
skjimon 3 months ago
Are there any good genetics lectures on you tube?
CSIR999 3 months ago in playlist Biology
@CSIR999 you could try to go to youtube(dot)com/edu
it's youtube's education page, you'll lectures and courses on your search, really good stuff
filmlovingmaniac 3 months ago
please please please upload genetics lectures really need them.
pleaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaassssssssssssssssssssssseeeeeeeeeeeeeeee
CSIR999 3 months ago in playlist Biology
I called you an idiot because your belief is "is just a gut feeling, or insecurity and need for reason of crap that happens." You typed that, didn't you? I can't respect anyone who thinks like that.
MrBazingafy 3 months ago
lol he says "this dude" a lot
serooter 3 months ago
@khanacademy Isnt it amazing how far our brains evolved? It passed the point of basic survival and "need" to the point where we cant ever reach the maximum capacity or potential of our brains. Not to be religious(i dont support any one religion), but that is a pretty good prove of a creator or intelligent design.
If you see this post elsewhere, its probably me feeling the need to share this epiphany. =|
notfree25 3 months ago
@notfree25 firstly, there are 3 types of natural selection, there is an narrowing in variation, a shift in traits, and a split effect. so let me explain this, our brains are an example of narrowing variation, the brain and the nervous system evolved to keep balance, just imagine a person that trips 2 or 3 times while chasing animals or running from predators, he wouldn't survive for long, then there came the problem of walking upright, which is economical(in energy) but not fast. I ran out of ch
quzishen 3 months ago
@notfree25 How is that proof? Darwinism eliminates the need for an intelligent creator. You're an idiot.
MrBazingafy 3 months ago in playlist Biology
@MrBazingafy and you are a close minded asswipe. Even Khan doesnt out-right say intelligent design doesnt exist.
notfree25 3 months ago
@MrBazingafy You know what, im sorry. Your entitled to your opinion that im an idiot. *shrug*
notfree25 3 months ago
@notfree25 Well I am an evolutionary biologist, so let me be the first to tell you what you said is absolute hogwash. There is absolutely no evidence that supports "intelligent design" (you might as well label that pathetic term creationism) and it hurts to see people flailing their ignorance in a subject they know little about
karim3343 3 months ago
@karim3343 seriously? do you guys see the word religion and decide that you have to argue?
How is spirituality any different from unproven theory? Last i heard, multiverse still has no conclusive proff and physicists swear by it. Are you calling them idiots too?
Here is a new word you to to learn today. "Verificationism". Bye
notfree25 3 months ago
@notfree25 First of all "spirituality" is not a theory. Secondly, the Multiverse is hypothetical. Physicists do not "swear by it", or else yes those particular physicists that you speak of should be labeled as distorting science with pseudoscience. Please do not try to claim that the Multiverse scenarios (of which there are 6-7 different versions, all understood to be mathematically possible in general scientific consensus) with that of "spirituality" which has no theory or conjecture. Thanks
karim3343 3 months ago
@notfree25 Thank you for bringing up "Verificationism". For your information, Verificationism is the view that a statement or question is only legitimate if there is some way to determine whether the statement is true or false, meaning your belief that Spirituality is existent in this universe, cannot be proved or disproved, thus should be discounted completely as not worth having a conversation over.
karim3343 3 months ago
@karim3343 so.. why did you decide to reply in the first place?
I chose my word poorly. Sorry.
Many physicists believe in multiverse, and make theories based on it, despite it being unproven.
Many people believe in a higher power, and place their faith in it, despite it being unproven.
Spirituality could either remain unproven forever, or science will eventually turn it into myth, or a massive spiritual event occurs.
I appreciate your civilized, matter of fact tone tho.
notfree25 3 months ago
@notfree25 I would like to agree to disagree, and leave it at that, but unfortunately what you are saying is incorrect. Physicists do not "believe" in the Multiverse, they have Mathematical theorems that provide for additional universes. Spirituality claims in itself to be unproven. It is so special that you can't prove it with Scientific conjecture. That is the whole point of spirituality. What good would it do if you could measure it? It would not give it that extra appeal if you could.
karim3343 3 months ago
@karim3343
So they are forced to "believe" it? The only explanation to their mathematical theorems are parallel universes?
notfree25 3 months ago
@notfree25n Not at all, there are many ways to explain these fundamental results. Extra dimensions, Many-worlds interpretation, etc. But these all center on the "different realms" if you will, of "things". The fact that this is not the only explanation means that it is not a given law. Physicists just say, "oh look, there is no Scientific law that goes against a Multiverse theory. Oh and look, a lot of these postulations work towards a Multiverse. Therefore it's certainly probable" That is it.
karim3343 3 months ago
@karim3343 i would leave it at that but hey, this conversation is getting kinda interesting. Also im an ass.
Can we go with "Oh look, there is (still) no way to disprove sprituality. Oh and look, weird stuff is happening that no one can explain. Lets call it supernatural and "a greater beyond" ".
Well, im having fun with this so thank you.
notfree25 3 months ago
@notfree25 First of all, Multiverse theories are explained very precisely. The only reason there is still ambiguity about them is because there is no way (yet) to test these hypotheses. With Spirituality there isn't even a theory, not even a conjecture or guess. I reason that this is where you input your "Oh and look, weird stuff is happening that no one can explain" Please state the "weird stuff. no one can explain" (there is a difference between something we cant explain yet and miracle stuff)
karim3343 3 months ago
@karim3343 Honestly, mine is just a gut feeling, or insecurity and need for reason of crap that happens. I dunno, im not a physiologist, im a tech student. * shrug*.
Have you ever meditated? Your a biologist right? could you explain that tingly feeling i get on my forehead when i place things near it, or when i focus/meditate on it, "miraculous recovery of terminally ill patients"? placebo effects and "power of the mind/belief"?
Maybe my interpretation of spirituality is loose. Also out or cha..
notfree25 3 months ago
@notfree25 I am sorry but you would have to be much more specific than just hearsay and social perceptiveness of these events. Could you give me a particular event that is actually so awe aspiring as to have not only no explanation, but also an understanding that we will never have an explanation? Those are two very very different things. There is already an understanding of how placebo effects work, "power of the mind/belief" just sounds so generalized.
karim3343 3 months ago
@karim3343 ._.
lets start with placebo effect and how believing a pill is a medicine can cure some people, while not others
notfree25 3 months ago
@notfree25 Sure ok. There have been many studies concerning the placebo effect. We know how it works, but understand the brain is still extremely complex, and to characterize all the hundreds of billions of inter-neural connections and protein functions will take more time (1-2 decades). But many processes that occur during placebo medications have already been categorized. Your genetics largely dictate whether you are more prone to the effect.....
karim3343 3 months ago
@notfree25 The brain has control over the body processes affected by placebos. Pain, motor fatigue, and fever are directly organized by the brain. Other processes usually regulated by the body such as the immune system are also controlled indirectly through the sympathetic and parasympathetic nervous system.
karim3343 3 months ago
@karim3343 ok fine, belief has no use whatsoever. Genetics and things that we still need to further study does.
i could ask about the birth of the first single cell, or the universe itself, but it could be explained away with chance occurrence. There is no larger meaning to life than an effect of your parents reproducing. Why does wave travel the way it does? It just does. Why does light travel at so fast? it just can.
imma stick with science and spiritualism can still compliment each other.
notfree25 3 months ago
@notfree25 I'm not saying people can't be spiritual, I am just saying that spirituality does not correlate with Science whatsoever. Spirituality has no Scientific meaning although I do believe it can help with someones life. As for the universe or first cell, that has nothing to do with chance, and your questions about waves and light are very childish. Of course we can explain why they do the things they do, but your real question is just, "Why?"
karim3343 3 months ago
@karim3343
If its not chance, what was it? =S
Evolution is chance and probability.
The condition at the moment was just right for a single cell to appear into existence? that would be chance. If conditions were different, would the organism had evolve to breath other gases?
new thought, are new single cells coming into existence even now?
Science is digging into the universe for explanations... what are you saying? we can stop if your getting agitated.
notfree25 3 months ago
@notfree25 Your arrogance on this topic in enormous. Unless you have a degree in this area I suggest you stop asking mundane questions with such arrogance and aptitude. Firstly, Evolution occurs from natural selection, almost 100 percent of scientists agree on that, so for you to propose otherwise is of immense ignorance. Secondly, open your mind. There is no right condition for life. Life can occur and survive at the most extreme and strangest places. Yellowstone’s Hot Springs, (continued)
karim3343 3 months ago
@notfree25 In bodies below the freezing point of water, entirely alone, The Galapagos Islands, Acidic Mine Drainage, Deep Sea Vents, in the coldest places on Earth, In the Stratosphere (Yes, the stratosphere—the layer of Earth’s atmosphere that starts at about six miles above the ground), we even have revived much older spores of bacteria from 250 million years ago... That is just our own planet. There could be life in other more "inhospitable terrain" on other planets (continued)
karim3343 3 months ago
@notfree25 Species that could be silicon based, or from some other exotic material. "Evolution is chance and probability" Again ridiculous assertion. Through natural selection those that reproduce more are usually those that live long enough to reproduce. They live long enough because of their more impressive characteristics in comparison to their environment (as opposed to another subspecies of the same animal which is weaker or has lesser traits etc.) This happening over millions of years has
karim3343 3 months ago
@notfree25 absolutely nothing to do with luck. May I ask your expertise in the subject because it seems to be lacking... "Evolution is chance and probability" I do not understand how you have the audacity to tell me this. I have been an evolutionary biologist for 6 years and studied at MIT and Harvard. I do not need you to arrogantly state to me inaccuracies. Being ignorant about something is one thing, being arrogant AND ignorant about it is another. You are telling me all the evidence (cont)
karim3343 3 months ago
@notfree25 (cont) we have over the hundreds of millions of years, and the last 3 centuries we have been collecting it, and that all the great scientists, like Charles Darwin, Richard Dawkins, PZ Meyers, etc. simply don't mean anything? Quantum Mechanics explains the origins of the Universe, and this explains the biological component. There is no question among Scientists, all of your misinterpreted pseudo-scientifc beliefs are not of any meritable discussion.
karim3343 3 months ago
@karim3343 dude..
yea, thats their condition. and they formed into a life form that strives in such condition. I never said the surface of the earth was the only right condition.
Im saying it was chance that life formed. Are you saying nothing is to chance? Why isnt new species forming in your toiletbowl?
It was your arrogance that made you reply to each of my comment. Not mine. Like i said, im having fun. I also told you honestly, Im a tech student. U mad. Lets stop
notfree25 3 months ago
@notfree25 In conclusion, Evolution is a fact. As I said there is no meritable discussion here that will change that. Your questions can all be answered in basic Biology course. See how much you understand in a Semester. I don't know how you went from asking is the formation of life just luck and chance, to now asking "Are you saying nothing is to chance?" Its very incoherent. Also, yes new species are forming out of "nothing", Its called Speciation. We can do it artifically in a lab as well.
karim3343 3 months ago
@notfree25 Evolution is not chance and probability, it's the exact opposite. Natural selection selects useful traits which aid survival, which is non-random.
Task5003 2 months ago
@Task5003 one thing about that argument (which you apparently read.. sorry about that) bugs me.
Do all species share a common ancestor?
What i meant was why didnt other single cells form (not from Speciation, but formed) from non-living materials, like that first single cell did.
Anyway i googled and one article imply that plant also shared the common ancestor.. Pretty cool...
Doesnt answer the question tho, was there only one single cell that formed or many but the rest died off?
notfree25 2 months ago
@notfree25 That's a good question. I don't actually know the answer. I was told all life started out as a bacterium (one bacteria) that began to replicate, and eventually formed modern cells, but I'm not sure.
Task5003 2 months ago
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@notfree25
"What i meant was why didnt other single cells form (not from Speciation, but formed) from non-living materials, like that first single cell did."
That appears to be the case.
Bacteria and Eukaryota don't share basic features in common that one might expect and it's unclear whether Archaea are an early branching of Eukaryota or a separate Kingdom.
Organisms compete... It wouldn't be terribly surprising if entire kingdoms had become extinct during early abiogenisis.
DeathofSpeech 2 months ago
And to answer that, do you think the universe owes you an explanation? Just because you are one being of 7 billion on planet in a solar system in a Galaxy of 100 billion planets, of 100 billion galaxies, that is evolved from a primate, over only the last 250,000 years. Do you really think that the universe owes you an explanation?
karim3343 3 months ago
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@notfree25 And to answer that, do you think the universe owes you an explanation? Just because you are one being of 7 billion on a planet in a solar system in a Galaxy of 100 billion planets, of 100 billion galaxies, that is evolved from a primate, over only the last 250,000 years. Do you really think that the universe owes you an explanation?
karim3343 3 months ago
Comment removed
notfree25 3 months ago
@notfree25 Well I'm no expert on this. But I'll try to explain my thoughts in 500.
Humanoids walked on 2 legs before they developed big brains. This causes a disadvantage for them. The humanoids that were smarter lived long enough to pass their genes. Working in groups proved as an advantage as well, so humanoids with good social skills had a better chance of being selected. Once social structures are in place things can get really complex and more advanced brains are favoured.
That help? =)
Sanngot 3 months ago
Evolution Dudes reproducing.
TheAnti6od 3 months ago
This was one of the first videos I've watched from the Khan Academy. Now, 4 months and almost 1100 videos later, I came back to this. What the Khan Academy has done for me is amazing, the amount of things I've learned is more than my whole high school experience. Sal Khan is my biggest inspiration and his work is truly amazing. Thank you for teaching the world.
078matthijs 3 months ago
Willie Nillie!!!!!!!!!!!!! hahahhaha
Valentinort 3 months ago
only critisism I have is that the black moth characteristic was important even before since the industrial revolution simply because there rate of survival was affected before it hence the smaller numbers that they have had.
ecos889 3 months ago in playlist Biology
This has been flagged as spam show
Our Lord Jesus Christ is not an animal , in fact he made animals just like people too.. He made all thins so how's that ?? i'm human and i'm not an animal .. God created me and God is not an animal !
MsNica002 3 months ago in playlist Biology
Our Lord Jesus Christ is not an animal , in fact he made animal just like people too.. He made all thins so how's that ?? i'm human and i'm not an animal .. God created me and God is not an animal !
MsNica002 3 months ago in playlist Biology
@MsNica002 It is not a good idea to take creation stories literally when it comes to science. You were created by your parents, so in biological terms you're an animal like all humans. This is not a bad thing (it's actually kind of cool). All life comes from evolution and it's a completely natural process. That's why there are such harmful things like viruses and bacteria and parasites. They are formed by natural processes. No God would create harmful things like those right?
vicksoma 3 months ago
@MsNica002 You are an Animal. We are all animals. Prove that we are not animals. We have all the functions of an animal, apart from the fact that we are of greater intelligence.
gothix114 3 months ago
@MsNica002 This comment is just arrogance, it seems you have no place for new discovery because of you religion. I'm a Christian, i still believe in natural selection because i'm open to new things.
Myawakenings 3 months ago
@MsNica002 By your definition, God created you (in his image) and thus God is human? Blasphemy. You should visit your local church and confess.
No one said God is an animal. We said human are animal. That doesnt mean God is an animal too.
Why are you even on this playlist? You sound intelligent enough to not make a comment like that. Trololololo?
notfree25 3 months ago
super bus
jubjubfriend64 4 months ago
Sorry, but i think your giraffes look like penises.
xArchangelSGE 4 months ago
creationists need to watch this :D
devilpizza123 4 months ago
Really interesting video.
MissLaManta 4 months ago
The americans need to see this, i cant believe they have debates over this. I mean how bad the education can be and still be a leading country.
kataevans 4 months ago
@kataevans What debate?
AtheismIsCorrect 4 months ago
@AtheismIsCorrect I assume he means the debate where Creationists seem to refuse Evolution point blank.
GreyPeaJim 4 months ago
@GreyPeaJim I thought that. It is ridiculous there even still is a debate, but I don't think watching this will convince people evolution is real.
AtheismIsCorrect 4 months ago
@kataevans
Not ALL of us are creationists.
berniebay 4 months ago
Apes don't have tails, dude. Only monkeys have tails.
Stevesrssrssrs 4 months ago 22
@Stevesrssrssrs Monkey and some character in Dragon Balls.
MissLaManta 4 months ago
@Stevesrssrssrs Apes are monkeys...
waksibra 4 months ago
@waksibra No, monkeys have tails and are not as smart as apes. Apes are Chimpanzees, Binobos, Gorillas, & Orangutans and are extremely intelligent, second or third in the world. Humans are first, Dolphins may be second, it's debatable.
Stevesrssrssrs 4 months ago
@Stevesrssrssrs I've learnt that apes are monkeys because apes evolved from monkeys in the same way birds evolved from dinosaurs. But, yes, people use different terminology.
waksibra 3 months ago
@waksibra That's like saying that humans are monkeys too because we evolved from apes!
Stevesrssrssrs 3 months ago
@Stevesrssrssrs correct.
waksibra 3 months ago
Great job Sal, greetings from Italy!
vikintosh 4 months ago
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"False. A mosquito will never birth a fly or a horse or a frog or a human."
So are you saying that your understanding of evolution is that it involves a mosquito giving birth to a horse?
Or are you saying that biologists consider evolution to involve a mosquito giving birth to a horse?
Because both would require you to do a little more reading on the subject. Just a little.
cherryghost7 4 months ago
wouldn't the peppered moths that weren't "as peppered" get hunted to extinction before the industrial revolution came around coz they would be easier to see without as many spots. not a great example iyam.
nicermog 5 months ago
@nicermog
Good point. The answer is perhaps that the 'unpepperedness' was a novel mutation at the time of industrial revolution. What would have been a harmful freak mutation in other times, became a very useful one in industrial environment. The rules of the game change as the environment changes. The same genes for craving sweets that made our ancestors survive, are now killing us by millions.
Happyascanbe1 5 months ago
these videos are amazing.. i learn more on youtube than i do in class..
sarahyeoh95 5 months ago in playlist Biology
Awesome videos! Just one little detail: in this video at about 17:20 you make a claim that seems to suggest how the selection itself is also random. No big deal, and i mention it only because it is often how creationists "understand" it and then start arguing that the complexities observed could not have arisen out of pure chance. If selection was random, they'd be right-- but of course we know that selection is everything but random. The very word gives a hint after all. Keep up the great job.
Happyascanbe1 5 months ago
Salman Khan should be awarded the Nobel Peace Prize for giving peace of mind to students all across the globe! B-)
(By the way, I am from Nagpur, India)
kaustubhchahande 5 months ago 36
Natural selection is only one of the forces that can cause evolution. You forgot to mention mutation, genetic drift, and gene flow. And related to natural selection is sexual selection.
mmalone1987 5 months ago
one of the things that rlly stood out in this lesson: apes have tails
NThornne 5 months ago
Monkeys have tails. Apes have vestigial tails but no true tail per se. We have a tail bone.
linzelj 5 months ago in playlist Biology
A tail on an APE WTF????????!!!????
QPEY07 5 months ago
@QPEY07 you are an ape and you have a tail bone. thats what youc coccyx is. you actually have the genetic instructions for making a tail, they are just never manifested... well.. they are sometimes. sometimes a baby is born with a tail. its a genetic mistake that accidentally expresses those genes that are responsible for making tails.
its called a "vestigial organ". we see it all around nature. if you are a creationist idiot, its all the proof you need that evolution is true.
volound 5 months ago
Natural selection is not evolution. It is the proposed mechanism for evolution.
Natural selection has been scientifically observed.
Evolution has not been scientifically observed.
Threnodist1 5 months ago
@Threnodist1 Yes it has.
linzelj 5 months ago in playlist Biology
@Threnodist1 observed instances of speciation have been observed.
mechanism of evolution + instances of evolution = evolution.
volound 5 months ago
@volound yes, there has been observed instances of evolution, but you make the very common mistake of convoluting macro-evolution with micro-evolution. Micro-evolution is extremely common and is attributed to the natural adaptability of a species. However, the change of a genetic code from one species to a completely new species (i.e. macro-evolution) has never been observed and lacks a sufficient mechanism to acheive it (no, mutation is not a sufficient mechanism).
Threnodist1 5 months ago
@Threnodist1 first you say:
"Evolution has not been scientifically observed."
then you say:
"yes, there has been observed instances of evolution"
you really need to sort your shit out.
"However, the change of a genetic code from one species to a completely new species (i.e. macro-evolution) has never been observed"
that is called speciation. instances of specitation have been observed, thats why they are called "observed" instances of speciation.
mutation is not a mechanism.
volound 5 months ago
@volound Also, speciation is more of a byproduct of our naming conventions than it is proof of evolution. We could say the chihuahua and the great dane are two different species, but really they are both variations of a dog. The problems with naming of species and speciation is really a different topic.
Threnodist1 5 months ago
@Threnodist1 "Also, speciation is more of a byproduct of our naming conventions than it is proof of evolution."
under the strictest possible definition of "speciation" you can posit, i can go out there and find you examples that meet that definition.
"We could say the chihuahua and the great dane are two different species, but really they are both variations of a dog."
and cats and dogs and bats and humans are all variations of a "eukaryote", "chordate", "mammal".. so? there was speciation.
volound 5 months ago
@Threnodist1 natural selection is the mechanism. natural selection is the process wherein the environment favours attributes (which are sympyomatic of genes) more than other attributes. this results in variations in allelle frequencies which accumulate. enough accumulations (time and environmental change) results in speciation.
each human today inherits approximately 100 mutations. thats only ONE generation.
im curious, do you acknowledge the chihuahua and great dane come from the wolf?
volound 5 months ago
@volound Natural selection competes traits that are already existant in a species. In the peppered moth example, there were already dark and light moths. Natural selection merely dictated which would thrive; it did not create the light or dark moth. And yes, I would acknowledge the shared ancestry of the two dogs (though i can't be sure of their common ancestor). The genetic potential for large and small existed in their common ancestor. Husbandry selected it. Not evolution.
Threnodist1 5 months ago
@Threnodist1 "Natural selection competes traits that are already existant in a species."
so how do you hope to account for the myriad examples i could give you right now that are obviously not? this is absurd. traits are lost and gained in their dozens/hundreds every single time an organism is conceived. this is one of the most absurd things i have ever read.
"The genetic potential for large and small existed in their common ancestor."
the genetic potential for ANYTHING exists in ALL genomes
volound 5 months ago
@volound New traits are never gained. Only lost. I can always lose information. i can never create new (in a naturalist environment). Mutations are either natural variations of the source genome or corruptions that result in deformity. Compare controlled fruit flies and fruit flies with artificially mutated genes, and the normal are the "fitter" every time.
"the genetic potential for ANYTHING exists in ALL genomes"
False. A mosquito will never birth a fly or a horse or a frog or a human.
Threnodist1 5 months ago