A Rational Argument for Evolution (Part 2)

Cont'd

This next example will provide and demonstrate the amazing predictive power of evolution, so we know from comparative anatomy, embryology, genetics, and the fossil record, that the tetrapods, creatures with four legs, arose from lobe-finned fishes. Now from the fossils we can predict, or we find, that there are no tetrapod vertebrates 390 million years ago, but they are clearly there around 360 million years ago, so as such we can predict that we will find the transition from lobe-finned fishes to tetrapod somewhere in that 30 million year gap. Armed with this information, Neil Shubin and his colleagues looked at maps of exposed freshwater sediments, which were about 375 million years ago. They formed an expedition and after five years of searching, found the needed transitional fossil… Tiktaalik.

Tiktaalik has gills, scales, and fins. it clearly lived in the water. Nut more importantly though, it had eyes and nostrils on the top rather than the sides of its skull, enabling it to peer above the water. It also had robust fins allowing it to push itself above the water and look around. Additionally, these fins have the precise arrangement of bones predicted by comparative anatomy. These appendages are best described as half-fin half-leg. Even more interestingly though, the Tiktaalik have sturdy ribs for pumping air, and they had necks. Fish do not have necks, and for them, their skull joins directly to their shoulders.

Therefore, using the tools from the fossil record and comparative anatomy, researchers can go to a precise location in the world and find a transitional fossil with the exact features that evolution predicts. Creationism simply can't explain this. And once again, using these fossils in the fossil record as a whole, we can construct a phylogenetic tree. Let's take a quick look at genetics and molecular biology. Can we construct phylogenetic trees from these fields… and the answer is a resounding YES. From genetics alone, we can look at organisms’ DNA and see precisely how it is changed over time. Every gene of every organism on earth can be analyzed and assessed for phylogeny. When we do this, we find that not only do we find the same tree pattern fingerprint of evolution, but that all of those trees are the same.

The same goes for molecular biology; every molecule synthesized in your body can have its history traced and a tree constructed for it. In fact, using medical biology and genetics we've even traced the evolutionary history of snake venom, something we couldn't do if evolution was incorrect. Not only are phylogenetic trees constructible for every branch of biology, but there are additional little biological quirks that can be used to construct them as well.

Endogenous retroviruses (ERVs) are one such thing. Basically sometimes a virus inserts into an egg or a sperm and remains inactive, but its genes are still there. It can insert at random so the odds of two unrelated organisms having the same viral DNA at the same location is simply unimaginably small. Think of it as dropping two needles from space and having them land on a football field in the same molecule of dirt. However, if these two organisms share a common ancestor, their DNA will of course show the same viral DNA at the same location. When we look at our genome we find not one, but dozens of these endogenous retroviruses in the same location and phylogenetic trees can be constructed from them alone.

So as I've shown, phylogenetic trees best explain the meat of every field of biology. This is only explainable by evolution, but that's not the real reason that scientists accept it. Science takes it one step further and accepts evolution as the only possible solution because all of the trees from every independent field of biology line up and match one another. they are the same tree using different methods to confirm its accuracy. Remember the age of the tree I discussed earlier? Most reasonable people will accept the age with just three independent points of verification. With evolution, there are literally millions of data points along all of those independently formed trees, and the trees line up seamlessly. This is why every rational informed person should accept evolution.

This wraps up my argument supporting evolution. Hope you found this interesting.

Let me know your thoughts! Do you have a different perspective?