[Jubloz]

Quote by: scofield Evolution is by now a very old theory, but is still itself evolving.

Yes, it's about a century and a half old at this point, but to say that the theory itself is still evolving is, perhaps, a bit misleading. The details surrounding and supporting the ToE are certainly changing and growing as we learn more, but the theory that Darwin managed to piece together is still fully intact.

Quote by: scofield For example, it was a natural conclusion that Human evolution had slowed down, but it was recently announced that in fact there is now much greater genetic diversity in the worlds population than expected - evolution is happening about 100 times faster than we thought it was!

This may also be a bit misleading. Because there are significantly more people than in the past, there's likely quite a bit more random mutations occurring as a whole, but it's not as if the percentage of mutations is necessarily growing.

To illustrate what I'm saying, let's say we have 100 of organism X in a jar, and a random mutation will occur in 2% of them. Under this scenario, we'd find that there were 2 mutated X organisms. Now, let's say we've got 10,000,000 of organism X in a jar, with the same potential for mutation. We'd find that a whopping 200,000 of the organisms had mutated, but not because their "evolution was sped up", but simply because there were more of them.

Of course, things are far more complex than this simple example, but I felt it necessary to demonstrate how scale can add quite a bit of confusion. Another factor in what you said, of course, would be that many people who had been isolated for geographic reasons can, due to technology, now come together and have children, which allows for quite a bit of genetic change.

Quote by: scofield As for hair-loss, this is still a largly unanswered question. Actually, that's probably not an accurate statement; in truth there are many answers, just nothing definitive.

I'd say that your second sentence is probably more accurate than your first. The savanna hypothesis is extremely popular, although it has its flaws. I tend to buy into the aquatic hypothesis quite a bit more, although it, too, is in need of fine-tuning.

Quote by: scofield For a long time the reigning theory was that we lost our fur to aid heat loss in warmer climates, but this would be at least balanced by the disadvantage of having our skin exposed to direct sun.

Right. This is the savanna hypothesis. The problem with it is that most mammals in warmer climates retain their fur, whereas it's extremely common for aquatic animals to be more hairless. Adapting to a semi-aquatic life would have had a lot of perks for our ancestors, including access to otherwise unattainable resources (like fish), an escape from the heat and from predators, significantly less stress on the joints and therefore a promotion of bipedalism, and even drastically reduced stress during childbirth. The development of a dark pigmentation would have been a somewhat simple adaptation to solar radiation in compensation for bare skin.

Quote by: scofield A more recent theory (Link posted in next post) is that we lost our hair to help fight bugs. Lice and other biting insects can be a major problem, which is why our still-hairy primate cousins place so much importance on social grooming. Indeed, it was reported this week that some monkeys actually trade grooming for sex!!

An idea which is not without problems. I can understand how being hairless could be protective against insects in some circumstances, but hair can also provide quite a bit of protection against biters and blood-suckers. Whether or not hair is advantageous or disadvantageous depends quite a bit on the type of insect, the particular group's social and grooming habits, and the context of the given situation.

Quote by: scofield I think evolution is a very solid idea that's not likely to ever go away, but I also think we have a long way to go before we fully understand it. On its own, it just doesn't fully enough answer all of the questions.

I fully agree that the ToE is here to stay, and that we've just begun to understand it; after all, the human genome was mapped only recently. On it's own, the theory of evolution answers quite a bit, but there is still much yet to be learned. Our purely molecular and chemical predecessors ending with abiogensis, and perhaps beginning with some sort of big bang, still requires much explaination, and I imagine that none of us will be fortunate enough to have our questions answered within this lifetime. That being said, there is far too much evidence supporting evolution to ignore the theory's implications.