Introduction
This is a description of the evidence for evolution. It is split into different parts to show the many different forms of evidence that are used. Each individual section provides good evidence for evolution, but on its own would not be enough to construct a theory of evolution from. Another problem with evolution is that its greatest effects are only seen over a long period of time, which means we have not been able to observe the major changes in the 150 years since the theory of evolution was first put forward in its modern form by Darwin and Wallace.
This makes it harder to show evolution than to show something simpler like gravity. To show that gravity works, all you need to do is drop a ball. It isn't that simple with evolution. With evolution we are looking for clues which show what happened. The clues take many different forms, and a convincing case can only be put forward if all the clues say the same thing. This requires a more in depth approach than is required to confirm gravity, and that is reflected in the wide variety of different strands of evidence that are used. To understand evolution, it is not only required to understand each piece of the evidence, it is also necessary to see how well they fit together. This requires some work on the part of anybody trying to discover the details.
When people attack evolution, the first thing that is necessary to check is whether what the detractor is saying affects the other pieces of evidence. If a way of showing that the fossil record could have been caused by something else, then we should see if that affects the rest of the evidence. If it doesn't then this possibility is very probably flawed, or at best should be investigated with a great deal of scepticism. Any theory that says X can explain the fossil record and Y can explain the embryology etc will be rejected in favour of a theory which says that Z can explain all the evidence individually and together.
One other point should be made clear. The theory of evolution was based around the evidence. The different strands of the evidence (apart from the biochemistry strand) were all known before Darwin and Wallace. What they did was to devise a mechanism which would explain all these in the best possible way. As new evidence has come in, the original ideas have been changed. This is not a weakness of the original theory, bu the strength of science. We can look again at the theory of gravity and see that all the evidence available to Newton gave him the knowledge to devise the theory of gravity, but this was modified by Einstein when new evidence came in. That is not a weakness of Newtons ideas, but the strength of science. So when in the essays that follow, I say "this is evidence for evolution" I should say "the theory of evolution is consistent with this evidence". I use the former as a shortcut, but this is an important point. Any theory tells us what data is evidence and the data we have will in turn modify the theory. The theory of evolution was not invented in a vacuum, it was devised as an explanation of the evidence.
What you should now do is examine the evidence and see if the theory is, indeed, consistent with all the evidence presented, individually and collectively.
The evidence
EmbryologyTalk Origins also have a page for this whole subject, that goes into a lot more detail here: Talk origins Common Descent page
