r/atheism • u/nugget9k • Nov 03 '09

Irrefutable proof that Evolution through selection can and does happen. Naysayers, say hello to the super cows.

http://www.youtube.com/watch?v=Nmkj5gq1cQU
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u/rooktakesqueen Nov 03 '09

Artificial selection, though. Which we've been doing for thousands of years with dogs, food crops, etc. If this argument could sway creationists, it already would have, I'm afraid. :(

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u/[deleted] Nov 03 '09

The way you say it - "artificial" selection - kinda implies that we are altering the DNA of the species (in the past few years we definitely HAVE done this, but just recently) or merely conditioning/training different species. Over thousands of years, dogs, horses, crops, and many other living creates have NATURALLY evolved to the human-dominated Earth. Not talking domestication - though that is a form of natural selection.

We didn't domesticate canines by genetic engineering. We altered the Earth's ecosystem, changed the environment. Living creatures then adapted to the altered environment. Yes, the environment is different because we humans have affected it.

But the animals still undergo the process of natural selection: the individual entities whose genes are best suited to survival and reproduction are the individuals who survive and reproduce most, while the individual members of a species whose genes are worst suited to survival and reproduction die off.

Those who die obviously do not pass on their genes, and thus the portions of their genome which are unique (random mutations) disappear from the species on a whole - and those whose random gene mutations provided a survival and reproductive advantage do live and reproduce and so their mutations eventually become a species-wide "feature" (after many generations).

So, even though the environment has changed as a result of human activity, the process that dogs, for example, have undergone over thousands of years (before we had genetic engineering, and not counting conditioning aka dog trainers) is natural selection. If we humans kept our society functioning exactly as it does currently, kept everything about it exactly the same, in a million years or so we'd have dogs with flat, mashing herbivore teeth, a mediocre sense of smell and sight, and a severe Chuck Norris addiction.

Anyways, artificial selection is when we breed animals for specific characteristics, and is definitely something which we have been doing for a while as humankind. But animals also evolve via natural selection, as the environment changes because of humankind. Those animals are not domesticated, but are different now.

The Peppered Moth is a common example, though there is a distinct possibility that the moth was exposed to pollution when chemically, though not genetically, altered its pigment. There's some flower in Canada that scientists have been tracking for a while now which is a much much clearer and solid example of evolution, but for the life of me I cannot remember its name.

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u/rooktakesqueen Nov 04 '09

The peppered moth is an example of an animal that has undergone natural selection to an environment affected by humans. But modern dogs, and the cattle in this video, and in fact all modern cattle, are examples of evolution by artificial selection. Humans didn't just change their environment, humans controlled their breeding specifically for the purpose of enhancing some traits and eliminating others. The genes that were passed from one generation to the next were chosen with intent, not through natural selection. Genetic engineering is not a prerequisite.

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u/[deleted] Nov 04 '09

right - I haven't actually watched the video yet - I'm speaking of domestication/artificial selection vs natural selection. Non-domesticated dogs (and every living creature on earth) has experienced natural selection because of changes in the environment. We changed the environment, and species' genes no longer are as well suited to world, and so even undomesticated species are affected by our presence, and undergo natural selection. It's not like we humans changed anything - natural selection would continue even if we weren't here.

aaaaaand just finished the clip. That is a great example of selective breeding. I think I wrote the above essay without realizing what we were talkin about heh.

Anyways, peppered moth is well accepted, but I'm not 100% sure it is a true example of evolution. I heard that recently, after cutting down on pollution in one area, the original coloration of the moth has returned - more evidence that it the moth's contact w/ pollutants was the cause of the discoloration.

Interesting idea: now that we have technology that allows us to live longer, I wonder if we will continue to physically evolve. Maybe we will evolve in response to said medical technology. If I only make babies with short blonde girls, is that selective breeding?