Evidence for Evolution?

Question

Please give me the strongest- the bottom line of evidence for Evolution. Please don't make it too long tho.

Answer 1

Evolution is a proven fact. The proof is as follows:
- Variation exists. Due to radiation damage, chemical insult, or pure happenstance, an offspring may differ from what it would be if it came strictly from the DNA of its parents. The variant may have some advantage over an unmodified offspring. Every commercially important plant or animal is a variant of the original wild type, sometimes to the extent that it is not cross-fertile with the original -- it's a new species.
- Selection exists, at first natural, and now artificial as well. If the offspring has an advantage, it will reproduce preferably to the unmodified offspring, and eventually dominate. Farmers select dairy cows for improved milk production, and other crops for other advantages, but nature selects species for improved speed, strength, fertility, and other useful attributes.

These are the two essential elements of evolution, and since both are existential statements which are demonstrated, the theory is proved. Which makes evolution something of an oddity among scientific theories, most of which are universal rather than existential statements and as a result inherently unproveable.

This proof that the theory is correct does not, of course, help in unraveling the evolutionary history of any particular species -- it merely shows that such a history exists. For details of the evolution of a particular species, one has recourse to genetics, fossils, and other evidence.

Answer 2

There are whole libraries of such evidence, and no
way to condense it into a small space. Beginning
with Darwin's Origin of Species and continuing to
the present mountains of evidence have accumulated in many different fields of science.
Many people forget, if they ever knew, that Darwin
was a creationist at the beginning of the voyage of
the Beagle. It was his observation of facts and
his thinking about them that changed him.

Creationists actually have one completelly
irrefutable argument, that is, that god created the
universe with all the signs of great age, even
though this is a false appearance. With this sort
of argument you could claim that the world was
created ten minutes ago, with all your and my memories of an earlier life implanted in us. There
is absolutely no way to disprove this argument
because it can not be observed or tested in any way, it is completely nonscientific.

Unlikely as such an argument may seem, it has
been seriously proposed. A book entitled Omphalos by Gosse (I can't remember his first
name) was published during Darwin's lifetime. It
proposed just this idea, that the earth was created
with all the indications of an earlier existence that
never occurred. Gosse's son, Edmund Gosse,
wrote a book entitled Father and Son, about his
father's life, in which he discusses the reception
of Omphalos by other people.

Answer 3

DNA analysis. Human DNA is only 1.2% divergent from chimpanzees DNA, and 1.6% away from gorillas. It also identifies certain genes that are contained in ALL life, from bacteria to humans, and those genes are used in showing phylogenic (species) relationships, and also help build phylogenic trees, also known as trees of life, which are diagrams of evolutionary relationships. the link below is the human phylogenic tree...
Also, remember the mutation rate of cells is well documented and has been observed time and time again...in the end evolution is simply a numbers game...by simple mathematical odds, at some point a mutation that will help an organism be better at survival will occur, and if that mutation helps the animal, it will survive and pass on that mutation. If not, the animal dies off...

Answer 4

Evidence for evolution falls into these categories:
1. Fossils show us that life has changed over time.
2. DNA, protein structure, and other chemical comparisons allow us to see the relationships among species.
3. Structural evidence includes such things as
-- homologous structures that are different now, but have a similar embryonic origin (arms of people, flippers of dolphins)
-- analogous structures that show how different species have developed similar adaptations when they have similar environmental needs (eyespots on butterfly wings, eyespots on fish tails, eyespots on cobra hoods)
-- vestigial structures that had functions in the past but do not function in that way now (goosebumps on human skin to make our hair stand up all fluffy and keep us warm, but we're not that furry any more)
4. adaptations such as mimicry and camouflage

Answer 5

By insisting "please don't make it too long" ... this is a bit limiting. There is a *lot* of evidence ... a LOT. And it isn't just one piece of evidence by itself, but the fact that all of the evidence confirms each other. (E.g. the age of the fossils verified using radiometric dating, and stratigraphy, and molecular evidence of how fast mutations occur, all three *independently* put the same estimated ages on certain evolutionary events.)

In previous posts, like this one ...
http://answers.yahoo.com/question/index;_ylt=AjpZ94JlJEYpHVvlJ7yI267sy6IX?qid=20061114162706AAJ3vs9
... I divided it up into 10 categories:

1. Evolution documented in the laboratory or in nature.
2. Fossil evidence.
3. Genetic evidence.
4. Molecular evidence.
5. Evidence from proteins.
6. Vestigial and atavistic structures.
7. Embryology.
8. Biogeography (the locations of related species on the planet).
9. Homologous structures.
10. Bacteriology, virology, immunology, pest-control.

(For more description, click on the link and read my answer.)

Of all of these, it is probably the genetic and molecular evidence (#3 and #4) that is the strongest. People often just think of fossils and they don't realize that even if a single fossil had never been discovered, the specific patterns that are seen in the DNA of living organisms, is solid evidence all by itself that animals are related by common ancestry. It's not just that we are "related", but the *degree* of relationship shows a specific pattern. Our DNA tells a story ... just as surely as we can tell from DNA that you are more closely related to your brother or sister than you are to your 3rd cousin. That same pattern shows up in spades in all life forms as well.

But as far as what I think convinces other people, the vestigial structures evidence (#6) is pretty mind-blowing. For example, our body is full of little hand-me-downs from our ancestors that have no useful function in humans, but do in our ancestors. Everything from the appendix, wisdom teeth, and tailbone, to the structures in your legs and feet that used to be necessary for grasping with the feet (like your big toes). These structures make no sense at all until you compare them to the exact same structrures in other primates, where they serve important functions.

Answer 6

I'm not sure if this is the strongest but this is rather convincing:

If you look at members of the ape family, specifically chimpanzees, you will notice that they have many features similar to humans. They have similar looking hands, with less well-developed apposable thumbs. They have similar faces. They have similar social tendencies to humans, only not as well developed. Their talk sounds a lot like human laughter. They have intelligence similar to humans, only not nearly as developed. With all of this, it's not suprising that they also share approximately 98% of their DNA with humans.

If you take this and combine it with the idea that individuals who are successful in their environment have more offpsring than those that aren't, it is clear that humans evolved from a relative of the ape family.

This is just one example, it can be generalized to all animals if you look at more examples.

Answer 7

Probably the strongest argument for Evolution is not a single opposing notion comes even close to producing a shred of evidence in support of it. Especially not the creationist conjecture that "God did it", which is based on the first conjecture that a god exists in the first place.

Answer 8

Defining evolution as a change of frequency of a gene or trait within a population, we can see evidence of this in domesticated dogs, cats and cows (to name a few).

New breeds of dogs are created by selective breeding - breeding those dogs with desired traits (increasing the frequency of that trait) and not breeding those dogs without certain desired traits.

Answer 9

A short answer would be microorganisms evolving to be resistant to antibiotics. I do a lot of microbiology and this is a large problem due to doctors prescribing large amounts of these medications and you can find many organisms which have evolved, making man made drugs ineffective.

Answer 10

The fact that you have to get a new flu shot every year because the flu virus is constantly evolving.