I have been having a debate with a creationist named Dave Lone Ranger on Free Republic (read it here). We agreed to each present three evidences for our viewpoints. After that, the opposing speaker would respond, and the presenting speaker would get the last word. I went first, and presented my case for evolution as follows:
When you see this (1) that is there to denote the passage. A reference will be posted at the bottom.
Evidence #1 The Fossil Record
When you start off with a 5 toed horse like animal, then higher up in the strata find a 4 toed horse like animal, then a 3 toed, then a single toed, what does that mean to you? The Geologic column is riddled with example after example of this. Here is the infamous horse series:
Here are other examples:
The Sea Sloths
Why is the fossil record littered with sequences that just so happen to be in an order that makes them look like they evolved? I cannot make sense of it without evolution. In fact, I think anyone who saw these sequences would suggest evolution, had it not already been proposed so long ago.
Evidence #2 ERV’s
Another Major line of Evidence is the Endogenous retroviruses (ERV’s). About 8 percent of our genome is made up of these ERV’s(1). On a rare occasion a virus will insert itself into it’s host’s genome at random(2), and the host’s descendants will inherit this and have the virus in their genome. Our genome is 3 billion base pairs, so it is extremely unlikely that any creature would share the exact same virus in the exact same place in the genome. But yet humans and primates do have the same viruses in the same places in their genome.(3)
2. The Blue Lollipops show the regions that HIV has inserted:
NOTE: When it says “distinct target site preference” it does not refer to one specific place, but rather a very wide range of places (the gene, the promoter of the gene).
Evidence #3 Embryological Evidence
Now, the first thing I want to make perfectly clear is that I am NOT referring to Haeckel’s work nor to his long discarded theory. Ontogeny does not recapitalate Phylogeny, but there are some interesting similarities in development which I believe are best explained by evolution.
Mammal Embryos develop 3 sets of kidneys(1). The first, pronephros, is the same set found in primitive fish like Lampreys.(2)
After 3.5 weeks, the mammal embryo replaces it. The second set, the mesonephros, is the same set found in higher fish and amphibians. In human males it gives rise to urogenital structures, while in females the remnants are vestigial. The third set (Metanephros) is the set which develops and becomes the adults set of kidneys, and it is the same set found in mammals and birds.
Snakes as well as Dolphins are known to develop legs as embryos, only to reabsorb them later. (3)
Whales Develop hair as embryos, only to discard it later (except for the nosehair) (4)
All Kidneys are listed here:
After this was posted, another member challenged me on the ERV's, claiming that insertion was not random. However, if you read the paper he cites, you will notice that it says the "envelope genes" are used in reproduction. So this isn't a case of a fully functional ERV, rather a case of exaptation. This material in the genome was used for another function.
Dave is not done with his rebuttal yet, but I do plan on keeping everyone updated!