Evolution and 100 million year old mammal hair
Ok, I just have to rant a bit about this to get it out of my system. A group on Facebook pointed me to an anti-evolution group. Bored and tipsy, I went over to it to have a look. It was pretty depressing, but this post at the top really got to me. It's a 4-minute video about the recent discovery about a 100 million year old strand of mammalian hair found in a chunk of amber.
What bothers me is that the narrator clearly has no idea about what evolution by natural selection is or how it works. They make two particular attacks that bother me:
1) "How do they know it's 100 million years old." Um. I don't know exactly. At 100 MYA, it's not carbon-dating. It was probably found in a geological strata that has been reliably dated using potassium-argon dating or just plain strata dating that reliably places it. Or maybe it's well established that it takes at least that long to turn tree sap into amber. Not my field, but this stuff is as well-tested and reliable as any process in science. If you deny this you deny electromagnetism.
2) Their real issue is the quote in which one of the scientists involved in the paper says that it demonstrates that mammal hair was established a very long time ago, it worked as well as it needs to, so it hasn't really evolved since then. They laugh at this - "the mammal hair is so perfect that it doesn't need to evolve, but the mammal itself needs to evolve from rat to lemur to whatever? As dumb as evolution is, it just keeps getting dumber."
This demonstrates such a lack of knowledge that a first-year biology student would burst out laughing. Evolution isn't about "perfection"; it's about sexual selection. It's simple. Some genetic differences provide a survival advantage to a creature. This survival advantage lets them live longer and produce more offspring. More individuals in the next generation have this survival advantage, and they in turn live longer and produce more offspring. Eventually, nearly all members of the species will have this advantage.
What's clear with this discovery is that mammal hair, 100 MYA, had reached a point where the actual structure of the hair didn't provide any survival advantage to one generation. No mutation of the structure of the hair provided a competitive advantage to the generation which had the mutation, so the minor mutations stayed minor. This, bear in mind, is just the structure of the individual hair itself, not how the hair is grown on the skin or other minor changes.
For example, many cat species have thicker, longer and denser hair on their skin than other species, because they evolved in colder climates where keeping warm provided a survival advantage. Thus, Maine Coons have long, thick, dense fur that kept them warm in a way that Siamese cats didn't need in their warmer climate. Nonetheless, both an individual Siamese hair strand and a Maine Coon hair strand, under a microscope, have most things in common, as well as in common with all other mammals. One just grew more of them (or thicker, thinner, etc.) on their skin than the other.
Look at the well-known evolutionary example of the gypsy moth, whose natural habitat are white-barked trees. When the air was clean, the white ones dominated and the odd mutated black moth was easily spotted by predators and eaten early in its life, producing less offspring. When the Industrial Revolution blackened the trees of their habitat, the white ones became easier to spot to predators, the black ones were better camouflaged, so after time the black moths dominated the species. Once the air got cleaner, the trees got whiter again, so the white moths eventually became dominant again.
Most of the rest of the moth other than their wing colour - the wing shape, the body shape, the number of legs and antennae of the moths, etc. - are the same, because their antennae and leg configuration provided no survival advantage to either colour of moth. There were probably mutations of these as well during that time - moths born with an extra set of legs - but they didn't either hurt or favour the lifespans of the moths with these mutations, so they didn't really change from generation to generation.
This is first-year college stuff. This isn't a complicated or difficult concept to get around. It's something that is observable all around the world, like the small population somewhere in South America whose males mostly have blue penises, just because chicks a few thousand years ago thought blue penises were hot so they hooked up with those dudes more often.
I just have to believe that these anti-evolutionists need to completely ignore the facts and the way evolution works in order to push a faith-based belief system. It's depressing and upsetting, and I'll be trying to not click on those kinds of links anymore to spare myself from a half-hour lost preaching to a choir of people who most likely aren't nutbags.
