Devolution

This is entirely unsurprising. A few days ago, the editors ran a rather random letter arguing that attempts to "teach the controversy" regarding evolution (a fake controversy driven entirely by religious fundamentalists) are misguided "attempt[s] to undermine sound science because of religious beliefs." Given that there seems to have been no reason to run the letter-- the topic of evolution had hardly been a topic in and among US politics, let alone Oklahoma politics-- I surmised that this was just an attempt by the editors to agitate its readership to gin up lots of anti-evolution replies.

I wasn't wrong. Indeed, it's nice to be right. For today, we get not one but two letters countering the earlier submission from Mr. Doane. In the first, Craig Hampton, Oklahoma City notes that he "[has] a bachelor's degree in a recognized field of science," and is therefore qualified to judge the truth of "sound science and religion masquerading as science." For anyone who is familiar with the evolution debate, these are classic lines-- first, the claim to have some professional scientific knowledge (though, admittedly, this one is pretty meager-- a bachelor of science earned some time ago is a fairly weak claim to authority), and second, the implication that evolution os just a "religion."

Mr. Hampton goes on to other classic bits of misinformation-- that "macroevolution" hasn't been "proven" and therefore, it must be religion. Unfortunately-- but nor surprisingly-- Mr. Hampton is uninformed and quite wrong.

Perhaps the best argument for "macroevolution" comes from genetic evidence in the form of HERVs, or human endogenous retroviruses. From talkorigins.org:

Endogenous retroviruses are molecular remnants of a past parasitic viral infection. Occasionally, copies of a retrovirus genome are found in its host's genome, and these retroviral gene copies are called endogenous retroviral sequences. Retroviruses (like the AIDS virus or HTLV1, which causes a form of leukemia) make a DNA copy of their own viral genome and insert it into their host's genome. If this happens to a germ line cell (i.e. the sperm or egg cells) the retroviral DNA will be inherited by descendants of the host. Again, this process is rare and fairly random, so finding retrogenes in identical chromosomal positions of two different species indicates common ancestry.

Imagine if scars on one's skin were inheritable-- if your parent had a scar, you would, too, in the exact same spot. If that were the case, you could look at a picture of painting of someone from the past and, if you saw the exact same scare on the exact same spot as you, be reasonably sure that that person was a relative.

This is essentially what we are talking about with HERVs. But it's even more compelling because we are talking about specific scars along very long and complex genome sequences. And when we look at one particular HERV, namely HERV-K, in primate genomes, we see something that looks like this:






















The writing at the top is hard to read, but they simply indicate the insertion points of viral DNA into the genome. All primates share the viral "scars" to the far left, but only "old world" primates share the viral DNA to the right of that, and so on.

It is hard to explain this other than to talk about common ancestry. Note, though, that there is potential falsification-- a hallmark of a good scientific idea. For instance, it would be a blow to the whole thing if the same retrovirus DNA were inserted at the same point in humans, chimps, and New World moneys, but not in gorillas or gibbons. Likewise, if we saw them in gorillas and dogs but not humans and chimps, the whole notion of what's going on with these HERVs would be wrong.

Of course, none of that has been shown to be true, but perhaps people like Mr. Hampton can hope...