Proofs of evolution

[Nelsson]

Hi! some people believe, biologists as well, that evolution never has or will take place. are there any commonly known allegations/proofs which contradicts the evolution theory, if so, which? what are the most accepted proofs that evolution has happened and is still occuring today?

Thanks for any respons:)

[Darby]

A biologist who doesn't accept evolution is like a chemist who doesn't believe in atoms - there's not much understanding there. And the list of contradictions come from people who don't come close to understanding what they are criticizing.

The list of evidence is long and varied - the fossil record of shelled marine animals especially (they are much more likely to fossilize); observations of adaptations in quick-reproducing species (it seems like there's something new in that arena almost every month - just yesterday I read about speciation processes from isolation of natural populations, can't remember the species though); comparisons of metabolic and genetic systems across broad swaths of living things (the science blog <i>Pharyngula</i> has a report on a recent conference up with many examples from developmental systems). It doesn't take much reading to find a huge amount of support, both observational, experimental, and simulational.

[Nelsson]

Thanks for your response:)..

I've been searching on the Internet now, and it seems that opponents of the theory of evolution claim that survival of the fittest and Darwins concept of natural selection only explain the development of individuals within a species.I've read so much by evolution critics, which argument with the fact that no dogs can suddenly get wings and fly and such bizarre scenarios. What are the basic facts/concepts that substantiate the evolution from one species to another? Is the only explanation that mutations, crossing over etc occur in one individual, which makes that individual uncapable of having fertile offspring with another individual of the same specie?

The evolution from one species to another is a slow step by step process, right?

[mith]

talkorigins.org has a good faq on positions of creationists and the scientific rebuttals.

[Darby]

Take your dogs for example - if you ran across, out in the wild, chihuahuas and mastiffs, would you classify them as separate species? The only reason we don't is that, being the products of artificial selection (we choose who gets to mate rather than their environment), we sort of think they shouldn't be. Anyway, that also tells you the sorts of major differences that selection can produce over fairly short periods (and how even the concept of species isn't black-and-white). Extreme changes in natural conditions can select powerfully - and although the selection works on individuals, it works on the make-up of the population as well, changing their average nature, sometimes quickly.

[MichaelXY]

Mith, you should post that talkorigins.org link in your FAQ. Pretty good site.
It can be like an catch all link for evolution questions.

[stevor]

Look in the current issue of Scientific American. They talk about how the differences between "species" is frequently just what we see when certain genes are activated (they use another word). The different species have the same genes.
As was mentioned by another with dogs, they would seem to be different species but they aren't. The same is probably for many other animals. Tigers and lions breed to make ligers. Though I don't know for sure, I think Ligers can't reproduce, just as mules can't. I think that being able to reproduce themselves is probably part of the definition of a species, but definitions are man-made and ...

There are probably a lot fewer species than we think. There's just many "breeds" of the species and it's hard to tell what is a different breed and what is a different species.

Though the article didn't imply it, this has great implications. If these "species" are just breeds with different genes expressed, then we could get back "extinct" species by finding what genes they have expressed, find a close "breed" and somehow trigger the genes of the "extinct species" in the relative.

[alextemplet]

I'm not so sure we can resurrect extinct species just by reactivating genes in living species. I think there are at least some differences in the genes themselves between species, although exactly how different two organisms must be to be classified as a different species is, I believe, a hotly debated subject.

Getting back to the point, I am often amused at the many attempts to disprove evolution. Most of evolution's biggest critics, I am certain, have never taken a single college-level biology course. Philip Johnson (the author of Darwin on Trial, for example, is not a biologist but a lawyer (can never trust those weasly lawyers!). Kieth Miller, who founded the Institute for Creation Research, has his degree in engineering rather than biology. The only biologist I can think of who is an outspoken critic of evolution is Michael Behe, author of Darwin's Black Box, and I am pretty sure he is widely considered to be a quack.

Biologically speaking, evolutionary theory is one of the most solidly-supported theories you can imagine.

[stevor]

Alex,

Though others might not be bioiogists, I majored in biology at the University of California. I am smart enough to know that not all that is "taught" is true. Check out that Scientific American article, read about the difference between "species" only being coloration, and then ...

[mith]

http://en.wikipedia.org/wiki/Breeding_back

[stevor]

Thanks, Mith. Interesting article.

The problem of breeding back is that there are so many genes and you'd be awfully lucky to get the right combination to breed back. But if both "species" have the same genes but different ones are expressed, it would be easier but might still entail a lot of genes to match up and figure out how to get them expressed (making a particular gene be expressed hasn't been figured out yet).

[alextemplet]

In my opinion Scientific American is not the most non-biased source of information, but that still doesn't change the fact that evolutionary theory is supported by vast amounts of evidence. I find it hard to believe that anyone who has seriously studied the subject can be anything but convinced of its validity.