Given Darwin's theory of evolution. What scientific evidence best supports evolution by natural selection?

Answer 1

There's a fair amount of it out there, but no one piece that is completely dead-bang. Still, it has made the theory of evolution predominate from sheer mass of circumstantial evidence. The kinds of evidence are usually grouped into four categories:

BIOCHEMICAL AND ANATOMICAL SIMILARITIES: All creatures are similar... even to the degree that there seem to be a few genes shared by virtually every lifeform in existance. Unless many of these creatures are related, there is no reason for them to look and be as much like one another as they do. Most of us would expect to be able to tell the difference between a group of five family members and a group of five randomly picked individuals. It's the same kind of thing.

GEOGRAPHIC DISTRIBUTION: Groups of related, similar organisms tend to clump together inside geographic boundaries. For example, Australia has a lot of marsupials, but other regions - even those with identical climates - do not. Further, we can also find examples of very closely related species separated by relatively new barriers, while those separated by old barriers are wildly different.

RECORDED CHANGES IN EXISTING SPECIES: We can observe instances of natural selection in action in species with very short generation times. Bacteria can be shown to develop novel genes to survive in new environments. We can also see how one characteristic has been favoured in one environment and not in another.

FOSSIL RECORD: Best of all, as far as we can tell all the above things have been occurring as long as there has been life. Nor does all life of all complexities seem to have sprung up simultaneously. There is no evidence of modern life at the oldest of times and almost no examples of ancient life that is still present in modern times. 99% of all species we know about came into and left existance before any human was around to see them.

In spite of a few of its grievous difficulties (the fossil record is notoriously spotty) I think most consider it to be the BEST evidence, in part because it also shows all the other trends mentioned above for millions and millions of years.

That's my take anyway. Hope that helps!

Answer 2

In my opinion I don't believe there is any 100% proof evidence for the theory of evolution. Evolution occurs over such a large timescale that in human lifetime we cannot see a clear chronological order of adjustments happenning within a population of organisms with a perterbation of the environment and see what happens. What there is, is a lot of bits of evidence from fossil records, bacteria, the wide variety of similar organisms yet with differences that one can measure makes them better for a particular environment. An example is bears particularly brown bears and polar bears where natural selection helps polar bear with white fur better survive in artic regions and conversely brown bears in temperate zones.

I suppose for me one of the strongest arguements for evolution is simply that all things evolve over time including cars, planes, technology etc. The Jumbo jet or Ferrari did not just appear but they evolved from the Wright Brothers first flight or from whoever built the first whatever could be considered a car. One could go back to say the chariots and that evolution of the car rapidly increased with the Model-T Ford rapid assembly.

Now this may suggest, since humans had a hand in evolving these things, that this may give proof of a God - the idea of Intelligent Design. Well I supose that then all depends on what your concept of God is. It is my belief that God is NOT some human form up there evolving things - for me God is simple nature and all the forces in the universe that was able to make things happen and as environments change nature is able to allow changes that make organisms adapt better and evolve.

This is my opinion - hope it gives some food for thought

Answer 3

Despite the fact I couldn't find Appendix B anywhere here are some examples: TB - the virus has mutated over the past 50 years and has adapted to become resistant to early anti-TB treatments; Chinese Lady Bugs - They have invaded North America and are becoming an issue. Have a look at the species itself and you will see why. There you go.

Answer 4

There is *lots* of evidence in support of evolution by natural selection.

Check the wikipedia entry for more details:
http://en.wikipedia.org/wiki/Evidence_of_common_descent