Patrick Michaels, not happy with butchering climate science, has decided to try failing at biology, genetics and ecology all in one go. In an article published at World Climate Report and naturally reposted at my new favourite source of idiocy WUWT, Michaels, the oil-funded shill from the CATO institute had a go at misunderstanding and misrepresenting a PNAS paper on polar bear genetics, and did a fantastic job.
When I first read Michaels’ article, I immediately thought about doing a large debunking on it, but to be honest, it is so wrong on so many levels, in so many ways across so many disciplines and in every single paragraph, I just really didn’t think I had the time to do a line by line destruction of it. I kid you not, this article is so bad, even my 12-year-old daughter was able to pick apart some pieces. So, rather than deal with the constant facepalming involved in picking it apart, I urge you to read it for yourself. Wear a John McEnroe type headband for protection. I have though, pulled out my favourite bit of Patrick’s obvious ignorance.
In referring to how polar bears might adapt to climate change he suggested that because there is genetic evidence that polar bears and Grizzly bears diverged a long time ago and because they are able to be hybridised in zoos and produce viable offspring, they will naturally be able to interbreed in the wild. He says,
“And, further, it seems rather than extinction, what a warmer climate leads to is an increase in interbreeding with brown bears—something which apparently took place with some regularity over the bears’ history, even more so in warmer times. So perhaps in extended warm periods, the polar bear becomes a bit browner—and takes on characteristics which are better suited for a warmer climate, only to re-emerge as the great white bear of the north when glacial conditions return.”
Yep, that’s what he said. Now, while there have been a few (3) recorded cases of hybrid bears in the wild, this notion that it is somehow going to be an easy thing is so simplistic and ignorant it beggars belief. For a start, the paper he is referring doesn’t paint a picture of polar bears and grizzly bears interbreeding easily every time there has been a swing in the climate. The last time there was any significant gene flow between the two was 150000 years ago and even then it was fairly limited. That is why polar bears are so genetically depauperate now. If it there was regular prolonged gene flow there would be much higher levels of diversity. But what about ecology? Not only are the two bears very different morphologically, behaviourally they are extremely different. They have different courtship rituals, different levels of aggression etc etc. It’s not an easy thing. But Patrick seems to be inferring that it’s a simple case that whenever polar bears come into contact with brown bears they’ll simply breed and become “a bit browner” and then when it’s all better in the next ice age, they’ll go back to being polar bears. This is where my young daughter said, “That’s stupid! They won’t be the same. They’ll look different,” and she’s right. The hybrids that have been produced in zoos and the 3 documented wild cases, are bears that are very very different, displaying characteristics of both parental lineages. They have white hair on their bodies, grizzly type heads, an arched back, and extended claws. They are also an in-between size. What second, third, fourth,…., hundredth generations would look like is impossible to predict as it would depend on the numbers and how much backcrossing there was etc etc. All the sorts of things Patrick really doesn’t understand. But that is assuming of course that that is a viable hypothesis.
A much more likely scenario is that in the short-term, polar bears will become extinct. The few hybrids that are produced during that death spiral will see their genes swallowed up by the brown bear population, and then, in however many hundreds of thousands of years when we do eventually slide back into an ice age, allopatric speciation will occur in the bear population and something, probably not resembling modern polar bears will emerge. That is of course provided we haven’t driven the brown bears to extinction by then.
So again, I urge you to check out the original paper and Patrick Michaels’ obvious ignorance and facepalm away. Thank me later.