re: #98 lostlakehiker

They have acquired genetic differences from the rest of our species that are adaptive in their own situations.

This is an incorrect way of view evolution. They don’t ‘acquire’ genetic differences, but genetic traits that are present in the rest of humans as well are emphasized there.

The prevalence of Samoans in the NFL is unlikely to be a simple accident; in times past, Samoans with strong arms were more likely to make shore ahead of the storm, or to be on the winning side of some naval skirmish.

That is really spurious; there are any number of reasons why body mass may have been selected for. Speculating about random reasons is just silly.

As humanity has fanned out across the globe and into more and more varied climes and environments, some quite recent [e.g., high altitude, big cities] it stands to reason that evolution has only sped up.

Again, no. That’s not what evolution is. If you mean that there’s been a higher selection pressure on us because of different environments, it’s true, but most of the selection pressure comes from bacteria, viruses, and other pathogens, causing a Red Queen effect; running in place, in an arms war. Humans are already well-adapted to nearly every environment because we’re humans— we can create tools, systems, and work together.

Ten thousand years from now, they’ll be arguing about whether or not we here count as human. And even that’s the conservative prediction.

This is completely wrong. We are really not very genetically distinct from ten thousand year old ancestors at all.

Meanwhile, can we perhaps notice that polar bears are evolving into marine mammals? Before our very eyes?

Yes, because it’s not true. There is no end-point to evolution. They have evolved in adaptation to their environment, part terrestrial and part aquatic. Saying they’re evolving into marine mammals is as silly as saying frogs are evolving into lizards or into fish.

You’ve got a lot of misapprehensions about evolution.