This is a great illustration that even I understand, from Think Atheist: http://www.thinkatheist.com/video/bang-goes-the-theory-evolution-made-simple
Evolution Made Simple
(8 posts) (5 voices)-
Posted 1 year ago #
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A very nice illustration of what happens during repeated replication with error. As the presenter pointed out, it lacks selection pressure (which would tend to drive changes faster), but it's a pretty good approximation of genetic drift.
Posted 1 year ago # -
it also lacks the group gene pool. this was an example of copying, erasing the one being copied, then copying the copy, erasing the previous, etc. There was no sexual reproduction, only copy errors.
I still enjoyed the simple, the visual, and the experiment nature of it.
Also, I just thought how if you wanted to set out to make species that have no possibility of drifting genetically into a variety of species, I think an imperfect copying method coupled with sexual reproduction would be the worst possible design. Further than this, why do we reproduce at all? If there was a god that wanted friends, why weren't they all just made at once?
Posted 1 year ago # -
what I meant by the 'gene pool' is that it would have some memory of what came before, and would dampen some errors/drift.
Posted 1 year ago # -
Asexually reproducing species are best-suited to and most successful in stable, uniform environments. They are often derived from sexually reproducing ancestors who have evolved optimal form and function, and then discarded sex. But if the environmental conditions change, they are quickly out-evolved by their neighbors who still reproduce sexually, who are mutating at the same rate, but are able to reshuffle the deck and explore new hands with each generation.
what I meant by the 'gene pool' is that it would have some memory of what came before, and would dampen some errors/drift.
I have no idea what you are trying to say here.
Posted 1 year ago # -
Wow Len, there's a lot of great stuff there - statistics and the "9 reasons why you're a christian" video... thanks!
Posted 1 year ago # -
"Asexually reproducing species are best-suited to and most successful in stable, uniform environments. They are often derived from sexually reproducing ancestors who have evolved optimal form and function, and then discarded sex. But if the environmental conditions change, they are quickly out-evolved by their neighbors who still reproduce sexually, who are mutating at the same rate, but are able to reshuffle the deck and explore new hands with each generation."
all very fascinating, thanks :D . I didn't know that some asexual species had previously been sexual, I always thought there was some evolutionary branch early on in earth's history that separated sexual from asexual. Sounds like statement of fact, but if there is a specific point you are trying to make/address, I don't see it :(
"I have no idea what you are trying to say here. "
Well first, I was trying to point out that some interesting aspects of *Sexual Biological* evolution were not so evident from the video. No I was not trying to say that DNA 'remembers' its loving parents and their original genes.
One thing I was trying to say is that (I think) a mutated part of one individuals DNA may be (in its sexually produced offspring) *not* passed on, and that space could possibly (I think) be filled by the partner with a sequence which was accurate to the previous generation. In other words, not all mutations will be passed on. Some will be, (and new mutations will occur as well), but when I said 'dampening' I was referring to:
the event that a mutation, which exists, is NOT passed on. Especially when the 'original' DNA (*before* that mutation) is the one that is passed on (thanks to the partner) *instead*.I hope this seems clear. Or else perhaps I have demonstrated that whether trying to be concise, or aiming for detail, I am incomprehensible.
Posted 1 year ago # -
tread, obviously the way real mutations are generated and transmitted is much more complex then what the video show. In the case of sexually reproducing diploids like ourselves only 50% of your genetic material is transferred to your offsprings and since a newly accruing mutation is almost certain to be heterozygous (on only one copy of the two in each cell) there is a 50/50 chance that it will be present in any of your children and nearly 100% that your partner will not be carrying the same mutation and therefore your kids will either won't have the mutation at all or have one copy of it. Once you start factoring in things like recombination, repair mechanisms and selection things get even more complex.
The video do a good job in addressing two point that seem to be difficult for many people, one is the fact that each generation is hardly distinguishable from the ones immediately before and after it so you're not going to find a crocoduck and the second is that accumulation of small changes can generate a large difference (micro Vs macro evolution argument).Posted 1 year ago #
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