 Welcome everyone and happy Darwin Day. I'm going to throw the link in local chat but it is a worldwide celebration of the birthday of Charles Darwin and in general the principles of logic, rationality, science that he brought to the world in addition to his theory on evolution. So today's talk is the second one so I've actually started a tradition and carried through on it of talking about heroes of evolution and these are individual scientists who have made important contributions to science and particularly in the spirit of Darwin in ways that were novel or had to face the adversity of skeptics and so this year I decided to do two women, Lynn Margulis and Barbara McClintock and I call them the women who broke Darwinian theory and I've slightly modified it from the published title to just say of neo-Darwinian theory because let's be fair some of this was not Darwin's idea that they challenged by the time their work came about. So I am Stephen Geyser, I have a PhD in nitrogenics and cell biology although here in Second Life I am Stephen Zootfly. So without further ado I will be structuring this talk like I do before of a brief introduction of Darwinian theory and then talk about the women in science in this case and then a little bit about their impacts in the long run. So Charles Darwin, the publication of On the Origin of Species in 1859 revolutionized the idea of the origin of where all the species came to be on the planet and how they fit into a model, a scientific model of why they're there and why they look the way they do and his primary you know novel idea was that there's this adaptation to the environment which again other evolutionary theorists have been positing as well that species, organisms have features and characteristics that make sense for what they're trying to do either as a predator or as prey or for mobility but his unique additional unique theory that came to this was the idea of descent with modification and that is the idea that the inheritance pattern is encoded within the organism in some way and then passed on and that these traits are not adapting to the environment but that there is a selection mechanism a sorting as it were that's based on the environment impact on the organism and this is commonly summarized in many textbooks and that's what I have here are these dual ideas that you have individuals in a population where whatever this inheritance characteristic is has some degree of variability and the idea that organisms vary is as obvious as looking around you and then the other key part of this is that because of the dynamics of giving birth and offspring is that they you can have more organisms than you expect and so when you think about for example fish fish lay hundreds of eggs and we think about insects insects lay hundreds of eggs and even we think about slow breeding organisms such as humans that our generation time is such that we overlap we have grandparents even great grandparents and so if you even if you only have two children if two people have two children you're still increasing the population size and so Vic asked an interesting question where I use the term encoded to talk about some sort of physical characteristic of the body and he mentions chromosomes we now know that chromosomes and DNA encode the blueprint for the body the phenotypes back there at the time they didn't per se know a lot of Darwin's work at the time was contemporaneous with microscopy looking at these bodies of things that move around in cells but it wasn't really until I'll get to this the the influence of Gregor Mendel and talking about rules of inheritance where they really started to come to understand the physical aspects of the blueprints for the body and then so the inference that Charles Darwin was making from these two pieces of information is that if you have variants within a population that have the ability to not just people talk about it being survival but it's not so much survival as much as their fecundity that is how many surviving offspring they leave in each generation and that over time if you have these variants that are successful from a population perspective then they can change and they can come to predominate and actually change the population and so over time this can lead to new species and this was summarized in a diagram the evolutionary tree the idea that as species and individuals vary they branch off and become recognizable individual species and of course one of the key features of the species the definition is that they can't interbreed or their breeding population in and of themselves so Max Chattanoir mentions that Mendel's work was published in 1865 and that in fact Darwin had actually seen I think a preprint of that before he published on the original species but it really the problem with Mendel and the thing that is hard to appreciate is his work was actually rediscovered in the early 1900s and so it wasn't until some 40 years later where his impact was yeah early 1900 itself okay that that his work was really then widely disseminated and people started to synthesize that with Darwinian evolution so and this idea caught hold among the scientific community and was really revolutionized the way people thought about the origin of species and how we can represent to understand biology on the planet so and mentioning Mendel I just want to briefly mention that the the main idea of inheritance he had is that these features of of organisms and let's just take the example of petal color so you can find species that are always purple sorry individuals with a species that are always purple find some that are always white and these are called true breeding if you cross them you don't get a blend right this was one of the things that people thought oh maybe blending is how genetics but they don't blend you actually get one or the other and then if you actually go back and then rebreat these with themselves that one fourth of this very specific numeric representation and fraction one fourth of them uncover this recessive phenotype again and so I don't want to go through all the details and again I hope most people are familiar with the basic principles of Mendelian inheritance but the key thing here is that the coding of phenotypes of physical characteristics are discreet and they follow important rules and that there are patterns of inheritance that are important now one thing that's important to recognize what Mendel and this is in the next slide he purposely picked very discreet true breeding phenotypes that could be well characterized by the math that he wanted to do and using p as an organism and I want to just make one key point about this is that this is not Mendelian inheritance that's a very good job of describing the behavior of chromosomes and that of the seven characteristics he picked they all acted independent of each other and so this is the the principle of independence inheritance where these the one fourth math that I showed you about this dominant versus recessive in that third generation was true for every one of these and they in no way influenced each other so the idea here is if you think about flipping a penny the fact that you're also flipping a nickel at the same time they don't influence the probability what you're gonna get against so what also came to the forefront and again in terms of understanding inheritance patterns and the discreteness by which this happens started to change in the early 1900s and this was using the model organism of the fruit fly the genus Drosophila and this is in the lab of Morgan and Hunt where what they were recognizing is that if you think about some of these characteristics and patterns and phenotypes you can look at this independence was not always true and that in fact sometimes the same phenotype would always be linked they would always come together so that the progeny would say if they had yellow peepod then they actually always had or a high frequency had the purple pedal and so this argued that they were not independent and what we know now is that chromosomes these large bodies of DNA and sequences encode genes and that if they're close together they actually are physically linked and the things that late make them independent scales by distance so the closer two things are together the more they're linked the farther away they're not linked now what was the really important insight from this work is that you could create quote-unquote maps of where genes are relative to each other by looking at recombination patterns and so in those very rare cases where a yellow peepod would actually be inherited and offspring with a white pedal and the frequency at which you could describe this is something that you can help make these maps and in fact you still call this genetic linkage map in the distance the unit of that is the Morgan and so what this now you could do is combine this at the time with the idea that if you looked under the microscope and you isolated chromosomes for individual cells and you also did this during meiosis when chromosomes are duplicating and making copies and then making gametes i.e. the eggs and the sperm or say Ova and pollen but you could see these things lining up and these are the physical markers of passing on genes and inheritance and this whole idea that things are linked is because they're physically next to each other on one of these bodies and so this was kind of the state in the early 1900s where we could now really understand population genetics we had phenotypes to measure this one could bring statistics along and one had a sense that between the combination of understanding Darwin and understanding mutations and illegal variants that you could really explain the vast majority of evolution and so this movement was turned neo Darwinism this combination of genetic patterns of inheritance as well as mental and the idea of chromosomes being hard fixed physical characteristics of organisms and genes being something akin to beads on a string was the prominent idea and what I'm going to do is describe two things that really broke this theory from two pioneers in science Barbara McClintock and Lynn Markle so I'm gonna start with Barbara McClintock but any questions about basic Darwinian theory and kind of this neo Darwinian fusion at the time I mean one thing to be aware of is some people even today refer to what we now call the modern synthesis of evolution as neo Darwinism as it's as if it's the new Darwinism but it's actually termed for late yet tagline mentions you know I guess the late 19th century you know they really started to develop mathematics more and that's really don't think it when was Dubran ski maxed you know is that 1930s or 1920s I always that's so my reading I'd have to look them up Dubran ski he's kind of one who wrote but he's kind of considered the grandfather of like the mathematical application of population genetics but but anyway I digress so if there are no other questions about this idea of chromosomes and genes and neo Darwinism let's have a lot of them so born in 1902 and was a precocious identified as very smart person and actually went to college which was relatively rare for women at the time and received ultimately her her PhD in botany at Cornell University so you know she's recognized by some of the leaders of the research field as being talented and and various and very sharp and she did go on again this is early 1900s was actually an instructor and research fellow at Cornell and then moved to a few places where she was a research fellow and eventually settled at the Cold Spring Harbor in Long Island New York and the the accolades which I'll summarize here in terms of her her life work was that she was in 1944 elected to the National Academy of Sciences then by 1971 received the National Medal of Science the then 81 the Albert and Mary Lasker award which is generally considered a very good sign that you're going to win the Nobel Prize and then she received the Nobel Prize in Physiology of Medicine in 1983 the the award was for when we talk about jumping genes or transposons but the first thing I would just take you through a few of her publications that I really think one highlighted where she was in the field that even before she came up with her with the theory of of transposons what led her to that I think what were the key points that allowed her to come up come across that theory and what she actually had already received a lot of you know accolades for so her early work what she was well known for was being a very good cytologist and cytology is the act of breaking apart cells and fixing on microscopic slides the chromosomes and then characterizing what you could see again usually through sorry in the early days primarily through a bright field microscope or compound microscope and she was the one who was the first to publish on the the complement of chromosomes in maize which we commonly call corn and you know she was considered to be just a for a forerunner of one of the foremost experts and technicians at doing doing this type of work in corn but one thing I want to point out is that chromosome 5 had this physically noticeable knob that was at the end of the chromosome and the other feature that's important to recognize about the cytology is the even at the time the proportion of the part of the chromosome above the little horizontal line versus the bottom as well as the overall length and size of the chromosome were allowed you to identify which one you were working with and this was her follow-up publication where in general like I showed you in the earlier slide the same chromosome from the mother and the father in myosas typically lineup and make this very nice looking little spiral ladder type of structure and what she was publishing is that on occasion you would find chromosomes that were not partners we're not both chromosome 5 but maybe chromosome 5 and chromosome 7 actually pairing together and so what this argued when the first things is that there are relocations of information on chromosomes such that as they pair again they're trying to find their similar partner in order to undergo myosas to divide and that some chromosomes rearrange spontaneously and so this is starting to you know attack as a chink in the arm or the idea of chromosomes being these fixed structures that represent the physical blueprint of an organism and what she was also the first to characterize was this idea that genetic recombination these things that we observe in say fruit fly actually represented the behavior of chromosomes and so her paper a correlation of psychological and genetic crossing over in ZMAs was this taking advantage of the fact that you had this knob and then genetic information that in the offspring in the crosses you could correlate the knob to particular genetic information and so that's what she was showing here is that in these crosses the different features or the different gene characteristics were correlated with exchanges at the other end of the chromosome so again these are papers that even I find daunting to read so I don't want to go through the details but this was the key point from this is that this was very early evidence that chromosomes represent the chromosomes and their dynamics represent the genetic information and so I would say this was one of the key pieces of information for the eventual discovery by Crick and Watson that DNA based on its structure is the molecule of inheritance well no Vic I think she did get credit for this for this observation it's not what she's most well known for but it was one of these things that was a contributing idea to how DNA and chromosomes are what encode genetic information because otherwise people were just looking at things that tended to sort and migrate so this was I think the first well demonstrated proof they answer your question Vic and I think also and I don't exactly know the time in this compared to Drosophila but there are these polytine chromosomes that you can isolate from Drosophila saliva glands and they and they actually kind of replicate themselves without dividing so you can actually see them as sort of under the microscope a little better so there's also probably parallel work from the from the Drosophila labs that was also supporting this correlation of physical elements on chromosomes with genetic inheritance but I'm not as familiar with that literature in terms of the chronology of it and Max Chatmouir makes an interesting point here which is you know her papers were hard to read and a part of it was that she didn't have the terminology described what she was doing these these you know you look at genetics papers these days and people have very well defined ways of describing inheritance patterns and tables understanding the names of genes and and it involves people being just comfortable and familiar with math and so this was one of these things where it was difficult for her at the time among other difficult all right so let me go to the the pair of papers that are probably the most that really describe her noble prize when you work on jumping genes this is the origin of behavior of mutable loci in maize and induction of instability at selected loci in maize and what's important to recognize here is that in general people thought of genes with these inheritance patterns for the whole organism like you saw with Mendel's peas and that is you know if you have a yellow pea the whole pea is yellow and every pea in that plant you don't see peas that are half yellow half green that's just not the pattern you see and so the idea is these are fixed phenotypes and the genes represent that and I think what you'll see um sorry so one of the the conclusion from her work and this is I think related to the idea that she was really one of the first people to be thinking about the correlation and the mapping of chromosomes to particular genes is that this instability actually represented the uncovering of recessive phenotypes that if you're crossing two organisms then the the allele variance the dominant versions of the alleles that you see on the brown chromosome is what you should see in every single say kernel and what she would do in these crosses is notice that at a relatively high frequency this combination of recessive phenotypes would come through and so the kind of the most obvious and best conclusion of looking at something like that is that whole link sets whole linkage sets of genes are being lost which could be physically due to the breaking off of a chromosome at and so um I think that is kind of the key parts of understanding her work is that the representation of losing multiple phenotypes at once that also again was appearing in some breaking this one to four obvious pattern of inheritance that you'd see from Mendel and then the other phenotype that she was observing is this idea that within a kernel that should be again this dominant negative inheritance pattern of bronze versus you know yellow the mutant phenotype is that within a kernel you had what was mosaicism and that is something that you would expect to be yellow suddenly you're seeing lots of patches and spots of the bronze phenotype coming through the darker pigmentation and I have this highlighted in the slide is that this is happening at a high rate in developing tissue meaning that somehow the genetics within the cells of an organism one organism are variable and so I'm gonna I'm adapted some slides from a very good talk a Howard Hughes Medical Institute um video series featuring Susan Westler who was a plant geneticist from University of California Irvine and she did this very nice representation of what's happening here that we now know from the work of Barbara McClintock and that she again Barbara McClintock did propose the system of how it works that if you have a color gene that creates the pigmentation and it is somehow interrupted and mutated in a way uh with what we call a transposable element but just a fragment of it so that then now you have this yellow phenotype and people would also recognize that most of the time these are fixed mutations you don't see this mosaicism very often so the different ways of mutating the gene to make it so that the kernel is yellow and that in her observations if you added in this other genetic element somewhere within certain crosses the so-called activator elements or the ac we now call it the ac that it could cause the the the element that's interrupting the spotted kernel to just jump out and that there are other times where this these elements could actually jump into the gene taking something that was supposed to be colored and pigmented into into yellow and so the next slide demonstrates this idea is that the combination of this element this little interrupting element inside the gene within cells could be jumping in and out would lead to this mosaic pattern on the kernel and that in some cases when this activator is you know activating the ds element the dissociator instead of it sometimes just jumping in out of the gene what would happen sometimes is it would break the chromosome so that you would lose that fragment and uncover multiple phenotypes at one time and so again her work described this model in which elements that are within the genome are dynamic that they can be jumping in and out of genes and that there are other controlling elements that allow those to work and again complementary with other work at the time where you could identify repetitive elements in genomes using some basic chemistry but you can identify exactly where they were or what they were this idea of repetitive elements in genomes was kind of was basically she was the first one to to come up with this idea that they're in elements that they're in genomes they move around they can contribute to genetic variation and that this basically breaks the idea that within any sort of cell from an organism that you have this fixed phenotype as the organism develops again the idea of having this mosaic kernels is explained by different chromosomes within an organism being different from each other and Vic asked the question is this epigenetics this is not what we would call epigenetics epigenetics is the modification of DNA that changes the transcription the expression of genes without changing the underlying sequence and so what transposed on subscribe is actually changing the sequence of DNA because you are inserting or excising these elements from within a particular spot so the impact of understanding how repetitive elements are in the genome and i'm just going to pick a couple highlights from here because this is now something that as we've looked at a variety of organisms that are eukaryotic there's a percentage of repetitive elements in genomes from like five percent all the way into the 80 for a variety of different plant species and so uh you know it comes to human diseases we've identified active elements that we have now identified where in 124 different cases they've contributed to inherited disease and we've also there are lots of groups who are taking advantage of the mobility these elements in order to try and modify genomes there's a an ancient basically fish transpose on that was dead but they reconstructed the original sequence and they call that sleeping beauty so they reactivated in old active elements and you can use that to insert genes into into fresh organisms with genetic engineering this is work from university of minnesota that's just amazing so um now one thing i'll just mention though is that a lot of mclintox very forward thinking idea of why this would be the case why would you have elements jumping around was proposing that these are regulatory controlling elements for gene expression now i'm going to talk about this a little bit more later but that was something where in general she as a general rule that is wrong and it was something that she promoted and very strongly thought made sense and i'm not disagreeing with that with that proposal but ultimately as the science came through these elements are generally just considered to be selfish genes that they are just they tend to be these autonomously replicating sequences that again according to how evolution works are just trying to replicate and survive how they can but i do want to point out that as we understand the vertebrate immune system and so you guys know about antibodies and probably heard of b cells and t cells which again are the source cells for leukemias again a type of you know white blood cell cancer is that we have to be able to adapt to basically any type of organism invading us so we do this thing where we recombine gene segments of immunoglobulin genes the things that make antibodies in a way so that we have this incredible variability for them with which to and so the fact that it works this way is due to an ancient transposon system and that is the the rag one and rag two proteins used to be their own transposon and had these little um tag element sequences that could cause this recombination and so when you think about how antibodies are made and you're taking the different segments and recombine them into one final gene which is what's demonstrated here in the left hand side that this that this recombination of gene fragments to a final gene form is basically the expectation of a transposon to do so this is just an amazing example and that while it's only a limited example in terms of genetics it's actually a really important example for us to survive on this plan okay and uh again had a question from tagline about Down syndrome and about whether that's related to transposons and I'm not familiar with any particular ones Down syndrome is typically due to having three copies of chromosome 21 in humans but you can imagine there might be certain types of recombinations where you get partial duplication but you have trisomy for parts of it maybe due to transposon recombination between repetitive elements okay so let's move on to limber goals and again she uh a little bit old sorry a little more recent than uh mclintock where uh chicago schmidt university chicago again my graduate alma mater with a master's degree in zoology and genetics and then she got a phd in genetics from uc berkeley and joined the faculty and then became a distinguished professor at the university of massachusetts now the majority of her scientific work that i'm going to describe was in the 1970s late 1960s but again by the by the time near the end of her career she was recognized with the national academy sciences uh medal in 1983 again the same year that um mclintock won the nibble prize uh she was named given the william proctor prize of sigma chi uh she won the u.s national medal of science in 1999 and the darwin wallace medal of the lenayan society of london in 2008 so her primary challenge to neo darwinian theory was this idea that when we think very far back in evolution let's go back about a billion years that the eukaryotic cells again eukaryotic cells are ones that are complex and larger that we are we as humans are eukaryotes that those very early eukaryotes were the result of fusions between other smaller organisms at least in terms of key characteristics that there was some sort of progenitor eukaryotes and then some of the things that we describe as organelles or subcomponents of the eukaryotic cell were actually a engulfed bacteria and that it eventually just took up residents inside the cell because it provided some sort of beneficial adaptation and so this is from her original work um she actually also talks about flagella and the centriole as probably one of these things as well but the legacy that's largely left behind that's supported the most by the scientific literature is that chloroplasts and mitochondria are formerly bacteria that took up residents so again i don't want to go through this entire diagram because it's very complex and doesn't quite make the case i want to make but in this um article as well she provides a framework for understanding how to understand whether something was an engulfed organism that took up residents and this had to do a lot with i mean and the best criteria was actually isolating dna and saying hey look the dna in this organelle is related to bacteria that do a similar function and then other aspects of this that you could characterize over time would be the metabolism of the cells maybe the structure of the cells the life cycle of the cells versus organisms and any other sort of common phenotypic traits and so here's a representation of chloroplasts and mitochondria the role of chloroplasts in plants is to basically make chlorophyll and take that chlorophyll and convert it into basically usable chemical energy so ultimately making sugars so that the benefit to the organism is that you can take a physical property a physical element that is sunlight and then convert that into something you can use within organic metabolism and of course that's beneficial that you're just getting sunlight from the outside environment so you always have this net surplus of energy available as compared to trying to grow and use up that energy in the body again chlorophyll being green is one of the most recognizable aspects of of plants and also again single celled organisms that also conduct photosynthesis including blue-green algae and then the other organelle here is the mitochondria and the mitochondria is responsible for the very efficient oxidation of chemical energy to make carbon dioxide and water but the amount of usable energy one gets from mitochondria is basically 18 times as much as you would from what we consider just basic chemical metabolism that that is anaerobic in other words does not use oxygen so again one thing one of the key things about this conversion process is that mitochondria converts sugars plus oxygen into carbon dioxide and water and a whole lot of usable chemical energy for the organism now the reasons uh sorry within the context of the cell in this diagram here is the uh you know this example of a kind of generalized plant cell where you have the outer membrane you have a large central vacuole you have the nucleus that contains the DNA and then also within that you can have tens to hundreds of chloroplast or mitochondria and so these are very small and so vick asked the question when did mitochondria become part of cells before or after cyanobacteria so cyanobacteria came first because it's believed that the chloroplast are specifically derived from some variants of a cyanobacterium i don't know the i don't have the phylogenetic background to to understand that as well as i probably should but that essentially um the so the idea of photosynthesis developed first in bacteria that is the chemistry of the photosystems in order to use chlorophyll to transfer energy from sunlight across a membrane and then to build it up into the chemical parts of it and then um the the chloroplasts have the remnants of this of all these parts and abilities to do it within within the cell and so the timing of this is actually a good question i think it's probably about a billion years ago when eukaryotic cells are recognized as being found in the fossil record and the timing based on molecular clocks but in terms of the engulfment and the presence of this probably a little bit later one thing we do know from looking at geology of the planet is that for the vast majority of history up to before a billion years ago the world was largely anaerobic and around that time you can actually see an influence by the net effect of photosynthesizing organisms to change atmospheric oxygen so that again oh sorry i should say when we think about mitochondria being glucose plus oxygen to make carbon dioxide and water basically the chloroplasts does the reverse reaction well helps aid the reverse reaction of taking carbon dioxide and water and turning it into oxygen so the fact that um you know probably about 600 million years ago we started seeing an increase in the atmospheric oxygen for the planet indicates that there was a big bulk amount of photosynthesis so yeah anyway that being said the key thing that i think was important for uh around the time that margulis was studying this in chloroplasts other people were making very seminal contributions of mitochondria demonstrating that these organisms that these organelles sorry these organelles had DNA that was encoding bacterial like genes and that the structure of their DNA was in a circle so like i mentioned earlier eukaryotic organisms have big linear chromosomes that you can see cited genetically but bacteria and then these organelles as well have small circular genomes and so this idea i think is the most solid piece of evidence to say hey and now that we have so much more sequencing ability very much solidifies the idea that these were formed from an engulfed organism now in terms of thinking about how this inheritance pattern especially now that we know that these things have DNA how does that break neo-darwinism and the example i have here in the next slide that um is this this idea the term is called variegation and so the main thing that you notice in looking at this plant is that while plants are normally green throughout a young shoot and its leaves then this in some cases you find them with this very mosaic different pattern that's not solid one or the other so again in certain ways very similar to what we saw in the kernels that we're losing bronze and becoming yellow it's quite variable and this is actually explainable by mutations in chloroplasts where the the chloroplast distribution in cells changes and then the gene that's important for making the green is different as you get to different parts of the plant so again there's a little bit of a discussion that i i think we can address a little bit later about extraterrestrial organisms and plants and organisms and the chemistry required for them but let's let's i'll i'll address some of that later but this idea of having this genetic inheritance pattern that's again just not solid green or not green is something that again breaks this neo-darwinian theory and was again contributory to understanding how the inheritance patterns of organelles are important for for for the whole organism okay so now how does this also really challenge core darwinian theory and what i've drawn here in as a template using darwinian's tree of life is the fact that if you think about identity by descent what this merging of organisms really represents are two branches of the tree merging and so this is not identity by descent this is actually the merging of a new organism which again extends out and becomes something different and then kind of follows normal patterns this normal idea of identity by descent with with progeny but this is something that is i think this very important challenge to understanding the original darwinian theory so the thing that i find again very satisfying to think about this is that when we talk about the modern synthesis and trying to get away from using the term darwinian evolution it's important to recognize that what darwin described it's really for understanding the majority of life on this planet is not an accurate and full description it's not wrong but it's not a full and accurate description so in terms of science evolving our understanding of some certain topic in field this is a great example of of this and that's again really kind of puts the neo-darwinism theory to rest as a viable theory and one thing that's wonderful about this idea this what's called symbiogenesis is the term that margulis came up with is that as you start looking for it it predicts you'll find more examples of this and so this larger thinking that lin margulis started proposing is that random mutation natural selection are just parts of how evolution works and that some of the big leaps forward result from the mergers between different types of organisms this idea of symbiogenesis now sorry i should back up to the idea that organelles are due to this merging we call that biogenesis but symbiogenesis is this idea that this is a more widespread phenomenon that explains examples of evolution and so um let me say i'll say it from that's maybe or maybe not true it's probably not true the way she described it as being a most important driver of speciation however people have found lots of example where this is an example of the of a photosynthetic slug and what the slug does is it doesn't have the its own encoded capability to do photosynthesis but at a very early larval stage it starts sucking up algae and steals their chloroplasts and basically has the ability to nurture and allow chloroplasts to divide and what was found in this paper that is that one of the genes from chloroplasts is now embedded in the sea slug genome yeah the elysia it's such a great story and so this idea again this is another example where you don't have in a sense or whatever progenitor beginning of species you had you had the merging the integration not of a whole organelle but at least the dna of an organelle from a completely different organism into your own genome and so the idea that this is an important driver of evolution i think is something that is as well maintained and supported within within biology and the other thing i want to mention and this is not exactly lin margulis's theory but is related and she talked about this in many for examples as well is that she really basically described this larger idea that is a well established phenomenon of science which is the microbiome so if you think about again the last let's just say 20 years of science people are really talking about the relationship of say the bacteria in your gut to the whole organism's health and i talked about this in some previous talks about helicobacter and stomach cancer but that both when you think about the human body and the ones that they're showing here is they're talking about in the urogenital tract in the oral mucosa on the skin as well as in addition to the digestive tract inside that our health and our ability to metabolize and to interact with the environment and protect ourselves from the environment is related to this ecosystem that basically also lives on us and the important thing to recognize is that while we don't necessarily transfer genes back and forth you can find examples of quote unquote inheritance based on the bacteria you have in your microbiome that influences your survival and your fecundity as an individual and so i think that this is a key point and human microbiome is not the only example uh the um plant the root microbiome is a really important topic for understanding how nitrogen fixation that there are these really important ways that understanding these ecosystems influences our understanding of biology and the planet and and evolution so that being said i think you know she she um she really described that extremely well and she could take this from particular examples of looking at associations of specific bacteria or microorganisms on an organism that go back and forth so some really good examples of this are lichen you can also think about coral that that's a combination of fish and other bacteria a lot of interesting aspects of this that go on okay but that being said that's a topic for another larger topic for another time uh again anybody who's kind of read through thomas coons the structural scientific revolutions understands and anybody who's a historian of science understands that new ideas don't always take right away and so um uh thanks gantel yeah this was so i actually had a chance to go to a crisper conference uh a couple years ago at cold spring harbor and this is where mclintock had her lab and this is a building dedicated to to her and her name where she worked and the um uh and there's an interesting history of mclintock at cold spring harbor okay so i think partly and let's just also mention to be fair to the scientific community it was very difficult for mclintock to effectively efficiently communicate her amazing science she understood it um and she could communicate it in scientific articles but even then it was very hard for people to really understand something that was so new and then also just to be fair very technically complex and so this is an interest so there's a biography written about barbara mclintock called a feeling for the organism i've read it great book very well written anybody would enjoy it and it describes in chapter nine this important uh moment where mclintock wanted to convey her ideas at the annual cold spring harbor seminar series and people just were like we don't get it we don't understand it and we're going to dismiss it and so the chapter describes again two interesting things it kind of describes her kind of retreat from being highly active at the social aspects of science again part of science is being a member of a social community and some of the ability to get your important science across relates to your ability to communicate and interact with people and to influence them and then the other thing it actually describes the chapter is a very nice job of describing from other sciences point of view if you think of einstein or richard feinman that they could they their brains were so advanced that they knew their stuff and that trying to communicate that back down to even scientists who are brilliant but weren't familiar with it could have a lot of a lot of problems with understanding the science you're trying to get at and i think you know as a parallel within our own lives have you ever tried to explain something to a five-year-old where you know it so well that sometimes the stuff they say back to you so funny because you miscommunicated in a way that you didn't think was a miscommunication but to a five-year-old is very different so you know i think that this is an important aspect of her science that you know she really did become much more well appreciated as really in a sense other examples and other scientists describe the same phenomenon that the work in bacteria with the mood the mu phage the work with aloe elements in humans the p elements in drosophila really helps solidify this phenomenon and then she was really the first and the basis for understanding it and then the other so lindmore gullis was is a very interesting person in science and first of all this organelle theory of symbiosis the idea that two organisms are living in a symbiotic relationship that ultimately turns into the merging into one single organism was something that was met with skepticism early on as well because that was just such a new idea compared to how we understood cells and the inheritance patterns and this again contradicting darwinian theory of identity by now the second thing of course is that she talked about this idea of symbiogenesis that this is actually a driving force of speciation and evolution and that she really tried to argue against a lot of the paleontologists at the time like steven j gold that you know fossils can't tell us much of anything about what's really happening in the microbiotic world that you really need a microscope and other techniques to understand what evolution is really about and again as a general phenomenon symbiogenesis does not function very well to say every new species is due to this type of event and i think that that's one very fair criticism that she was in fact wrong about that that's been born out by by the science however very by lots of very good examples of this and of course the microbiome being a way to influence inheritance pattern strong idea too um then third one is just that she had this from some of the readings and writings that i've i've read of her she's pretty ornery that she really didn't mince words and she really again the way some people described it like uh cherry coin from university chicago is that she really took the percent the perception that she was right and that you were wrong and that it was really hard to challenge her ideas when she wasn't listening very well so again i don't want to judge too much that because i haven't read through everything in detail but um i think that that's an important aspect of science is that you know it's you do have this community where you're debating the ideas and at least from my own personal perspective it's very important to i think be ready to strongly defend a logical idea but to not let your ego interfere with your commitment to it so um there's a very good essay and um again i'll put together my link collection for the final upload for this in a few days this guy is a tough bitch and this is really interesting article or book series by john brockman which is called edge which you'll find at edge.org where he'll have somebody write an essay and then specifically invite other luminaries in the field to comment on it and so if you want to see a very interesting conversation um then and i'll just go and pop this link in here real quick is that um this ends up being a very interesting conversation and you can see that many people do not like to uh soften their stance on their opinions so nonetheless and what i want to summarize here is that um you know these are two people who were novel creative and insightful and challenged the current thinking of the time and both of them had science that backed up exactly how the science needed to evolve and again this is your standard structure scientific revolutions examples uh as described by thomas kuhn and um and yet i think well okay so vick i'm gonna i'm gonna address vick's question says vick said would she have been ornery and that's a term i picked very precisely if she were a male or assertive and one thing i want to point out is one thing i changed in my slides is that i called it again if you take a look back challenges as pioneers in science because one thing i didn't want to per se judge is that the reaction to these women's ideas was because they were women that were right or whether they were just pioneers that were challenging the idea and and then to ask you know what how would other people describe lin margulis i think anybody would call her any number of words that also do have a female uh discrimination aspect to them and uh and i think that that is the thinking that we we need to make sure we get past that we again when i talk about getting away from egos i think a lot of certain discrimination and bias is because we have egos maybe not just about ourselves but also about larger populations to which we belong or we see others as not belonging but i did think the term ornery because i think you know we think about i think ornery is a pretty non gender descriptive term that uh she really was if you look at her writings and you could take her writings and take her name away from them and you would be like wow that's that's pretty pretty aggressive way of putting that or pretty pretty uh yeah aggressive way of putting it whether you saw a name on the writing or not so i'll put it that was answer your question vic i don't want to get too much again i really primarily wanted to focus on the science about these um of these of these women uh and i but i will admit that i'm quite sure that there was quite a bit of dismissiveness from some individuals within the scientific community because they were women but i i don't want to assert any particular person having done that so anyway so two heroes of evolution that really helped bring us to what what is a very modern and different understanding of what darwin originally proposed what were the modifications to darwinian theory uh from the merging with with mental and to recognize that really a lot of our understanding of of how evolution is a unique field comes from and the dynamic nature of evolution and chromosomes and genomes and genes really comes from from these two women so any questions i would like to thank this small dedicated crowd of people coming out for darwin day you can probably still find events in your area it is an international celebration thanks max yeah you know my one of my fields that i professionally was in and published in was was retro transposons a type of transposon class i'm very tempted to do that to do a history retro transposition of transposons more dedicatedly so we'll see maybe by the end of summer i can put that together yeah thanks shantel yeah i've done i've done a few talks for the science circle but any questions or any thoughts on you know modern evolutionary theory or anything else to just celebrate darwin day well you're welcome shantel i think yeah taking some time to really celebrate darwin day every year and hopefully talk about again recognizing darwin but recognizing how science changes in darwinian evolution theory is is pretty pretty important well vik actually what i i will recommend and this is a talk that i had given before it's a little bit dated now but there was a 2009 nova pbs documentary called what darwin never knew and i think if you watch that it's about a hour and a half long documentary that should be freely available still i think that's a great place or you can see my talk where i talked about that documentary and that would be in the archives yeah yeah so well yeah socially based on actually i think primarily one book but also kind of series of book by by shawn carol who was used to be at university wisconsin madison now hhmi director of education outreach and uh yeah he's written a whole series of great books remarkable creatures was really good he's a great writer all right well with that it's i hit i've hit one oh well sorry i've hit um 1101 second lifetime so i'm gonna go and close my mic and maybe stick around for a little bit of local chat but then i've got to get up and stretch move around a little bit oh okay what so all right good luck good last question are there darwin award nominees is what darlin darlinda is asking and uh the darlin awards are a slightly different award than um then what the scientific community is recognizing but um it's for people who in certain ways exit themselves from the gene pool in dramatically misguided ways shall we say that's a great reading now i i know you know darlinda it's but if anybody wants to look those up you might enjoy some all right so i'm gonna go off mic