‘What would change your view on evolution?’

I hear that question posed from time to time. Sometimes it is directed at me, but more often I hear it directed towards established (and often famous) scientists. It’s usually a product of creationist rhetoric where the answer doesn’t really matter. Regardless, it is an interesting question.

What would change my view on evolution?

It depends what is meant by “change”. My view on evolution changes quite frequently, actually. Sometimes it’s a qualitative change: the relationships between our known ancestral cousins are always shifting ever so slightly. Often, there is little consensus about where to place certain members of the genus Homo on the evolutionary tree. As new evidence is found, as more research is done, as further facts come to light, my views are always changing on that aspect of evolution.

And then there are quantitative changes. One excellent example comes from the discovery of tetrapod footprints. That discovery pushed the evolution of tetrapods back about 18 million years. All the relationships between species of that general time period stayed the same, but our view of when tetrapods began to populate the land changed.

And then there are all sorts of other changes, like recently when it was shown that natural selection works differently on allele fixation in sexually reproducing populations versus more simple asexual populations. (That was also a qualitative change, but on the genetic, not taxonomic, level.)

So if that is what is meant by “change”, then there are all sorts of examples that show how my views on evolution are, well, evolving. The same can be said of biologists around the world. But what if by “change”, the real question being asked is, What would make me dismiss evolution? Then the answer is very different.

As I recently explained, a basic fact of science is that it does not tend to operate on individual studies. It requires a body of evidence to change views. For example, I reject a connection between cell phone use and cancer. Studies have shown possible links, but they have been far from conclusive, weak even. And more importantly, there is a body of evidence showing no significant link. I’m going with the evidence in bulk, not the individual packaging. This relates directly to the question of what it would take to get me to dismiss evolution because there is a famous quote by J.B.S. Haldane I had in mind when starting this post. When asked what it would take to change his mind, he retorted,

Fossil rabbits in the Precambrian.

But that wouldn’t change my mind. My very first suspicion would be fraud; I suspect little more from creationists (and we know how much they would be promoting such a discovery). But let’s say it came from a reputable research team, then what? I would admittedly be perplexed. There is no reason a fossil rabbit ought to be found in that era, but that doesn’t mean we get to throw out such a well established theory as evolution. We know evolution is true insomuch as we know gravity is true. It would necessarily take more than a few rabbit fossils to alter the unifying theory of biology, just as it would take more than an apple falling up for us to alter the theory of gravity. Even if we could never explain the fossils satisfactorily, I would have no doubts that evolution still formed the basis of my field of choice.

What would change my view would be the discovery of a number of fossils in all the wrong places. We would need to start finding mammals and birds dating back 800 million years; we would need to see dinosaur fossils embedded in the rocks of 20 million years ago; we would, yes, need to see rabbit fossils in the Precambrian. No, I don’t need these specific examples, but I do need these sort of examples. I don’t want just individual anomalies that fly in the face of modern theories. I need more than that: it takes a body of evidence to start changing my view. Because that’s how science works.

2010: FTSOS in review, January to March

Yes, this is one of those lists. And there are going to be four parts. Deal.

January:
There was some good stories from this month, but I can only focus on a couple. One of my favorites was the discovery that pushed tetrapod evolution back 18 million years. This was a quantitative change – not a qualitative one. That means that the discovery did nothing to change the relations scientists have constructed for species at and around that time (397 million years ago); it only increased the time frame in which we recognize tetrapods to have lived.

This was also the month when I was attacked by a bunch of caricature feminists. The whole issue arose over my position that a picture of two fat women on CNN was an objectification of fat people (because it accompanied an article about fat women). The caricature feminists took this to mean that I hate women, don’t think they should have any rights, and as I recently saw in an unrelated thread on an unrelated blog 11 months after the fact, that apparently I’m also racist.

And then there was the first threat of the Maloney Mess. It is not clear how the maker of that threat knows Maloney, but she apparently knows him well enough to be aware of the profession of his wife. (Everyone now knows she’s a lawyer since she amateurishly issued a cease-and-desist request, but that happened only recently.)

February:
The big hubbub during this month was the suspension of FTSOS. The reason had to do with Andreas Moritz and Christopher Maloney. I hardly need to go into great detail at this point, but briefly: I made a post criticizing Moritz nearly a year earlier. I later made a post criticizing Maloney. The two got in contact with each other as a direct result. Moritz emailed WordPress with information provided to him by Maloney. The claim was that Maloney was a doctor (not true) and I said he was not a doctor (true). Since there was a threat of a lawsuit, WordPress demanded I change or delete my statement. I did. But I was suspended anyway. As it turns out, Maloney is a naturopathic doctor, not a real doctor, so I was always in the right. But that wasn’t important to anyone at the time. Well, except Simon Singh, Richard Dawkins, PZ Myers and a number of other defenders of real science who helped publicize the censorship. And presto, I am back.

This was also the month when FTSOS hit the arbitrary mark of 100,000 views. I have always been open about the fact that I am fortunate to have images show up in Google Image, but the vast majority of views come from posts with substance. And really, that has always been the trick: Put up content that interests people and they will read it.

One of the biggest non-Moritz/Maloney posts was the one about circumcision. I always feel the reactions to these sort of posts end up very skewed because much of the absurdly vehement opposition is just that – absurd and vehement. It is a vocal minority being vocal. But they do have legitimate concerns. In fact, I suspect if I wrote that article again, it would go through some significant revision. But I do not see myself ever sharing the inane passion against circumcision that the anti-snip crowd displays.

March:
My favorite post from this month was the one on mitochondria and microsatellites. I wrote about the difference between how the two are utilized in studies on populations and evolution. Mitochondria is good for the long-term, but microsatellites can be very useful over short periods, perhaps over a few thousands generations. In the post I cited one study on the spatial and temporal structures of populations of Atlantic cod off the coast of Canada and Maine, extending to Nantucket Shoals.

There was also the heartbreaking story of Constance McMillen. Her bigoted southern school would not allow her to attend her prom with her girlfriend because, well, it was a bigoted school. A judge ruled as much, but the school then encouraged parents to create a private prom to which Constance would not be invited. Constance has since moved on, receiving scholarships from celebrities and others who respect her for being a human being who matters.

Another heartbreaker comes from the post about Kelly Glossip. Kelly was in a relationship with Dennis Engelhard, a police officer who died while on duty. And even though they had long shared their lives together, Kelly was not allowed to receive any sort of survivor benefits because the two were legally prevented from entering a same-sex marriage. I think if more people bothered to realize how their anti-gay, pro-bigot stances hurt real human beings, we would start to see a lot less opposition to equality.

Finally, I have to break with the short-lived tradition of only featuring three posts per month because I just have to mention my article about the reasonableness of absolute uncertainty. I wanted to explain what atheists mean when they say “There’s probably no God” since so many people seem to think atheism is the same as certainty. It is not.

Expect April to June tomorrow.

Neglected point

One point I neglected about Tiktaalik is that its ability to walk on land was limited. Its limbs wouldn’t have been able to support it terribly well to do terribly much. Its life was likely spent more in the water than on land.

Coupled with the recent discovery of tetrapod footprints in a marine environment, the way to think of all this is that tetrapods did evolve at least 400 million years ago, but there were clearly still viable alternative lifestyles to go alongside fully terrestrial life (and still are). Nothing demands evolution be perfectly linear. (Neanderthals lived at the same time as our direct ancestors as recently as 30,000 years ago.) A further important fact is that while probably 90% or so of all fossils come from the ocean, they tend to be from the more settled sediments, i.e., not the shoreline, the evident habitat of these newly discovered tetrapods. That indicates a possible sampling bias. Just looking at Tiktaalik, it’s clear that its freshwater habitat lent itself to preserving fossils – aside from the area being targeted for its fossilizing properties, there were several examples extracted from the site.