Evolution - Understanding the Debate Pt2

This video is the second in a series meant as an introduction to some basic concepts involved in the public debate about evolution, emphasizing common misunderstandings. In this video, I talk about neutral DNA and Genetic Drift, and contrast Genetic Drift with Natural Selection using a simple experiment involving M&Ms.

Category:

Education

Tags:

• Evolution
• neutral
• junk
• DNA
• Genetic
• Drift
• Natural
• Selection
• Creation
• Creationism
• Intelligent
• Design
• ID
• m&ms
• experiment

[gertomaniac]

Junk DNA is just DNA that has not yet been understood.

[EvoBiologist]

If that were true, then we'd all be truly screwed by the ~200 mutations each person gets each generation. If most DNA isn't neutral or very nearly so, then we could never handle the mutation load. That's a mathematical fact.

[gertomaniac]

@EvoBiologist: "Not neutral" is not quite the same as "very nearly so". Some parts of the junk DNA has already been proven to mean something in the last decade.

something else: It's quite striking, how a lot of otherwise well-informed guys can't correctly draw the distinction between evolution and genetics.

[EvoBiologist]

Other DNA referred to as "junk" is actually completely silent and can be mutated with no effect.

Since Ohno decided to call all non-coding DNA "junk", it's hardly surprising that we found uses for a bunch of it. Nowadays, most serious biologists rarely use the term because of all of the baggage associated with it.

Regardless, my point was that by far, most of our DNA could be mutated without any significant damage to our ability to survive and reproduce - if this were not the case, we'd die.

[bigchurp]

you do a great job explaning evolution.

[SomeStylistGuy]

Dude... when the religious rite shows up with torches and a stake.... DON'T get the M&M's out. That just isn't making the case.

[SGresponse]

"Mmmm... Selection"

That made my day!

[EvoBiologist]

A big dog doesn't have "increased information" over a little dog, only different timing on genetic growth switches.

Dogs did have to mutate to evolve from wolves. In order for the differences between dogs and wolves to last through the generations, the physical differences have to be based on genetic differences. Pure bred dogs have gone through many population bottlenecks, meaning most of the changes arose from variation that only came about in inbred populations - new mutations were needed.

[gregrutz]

Does a big dog have 'increased information' over a little dog?

Or does all dogs coming from a wolf show they didn't have to mutate to evolve? Micro evolution is evolution given enough time,

[LeopardFrogPilboxhat]

Because the infrastructure involved in genes, the promoter, activators, splice sites, regulatory elements, are so improbable to just mutate into existence on their own 20,000 times evolution predicts that all genes should fit into a family tree.

And this is what we see with no exceptions anywhere. When we look at lineages we see genes get copied and then mutate to cause changes.This is why genes are said to be members of families.