Moi, defender of science? [UPDATED]
However, I have not learned squat about evolution since, um, 10th grade honors biology with Mrs. Schwartz. (It wasn't even AP. We didn't have AP Science classes.) I never took an evolutionary biology class in college at all. Seriously. Everything I wrote here I gleaned from 10th grade (I did do very well in that class) and, I guess, from reading the newspaper since then.
Are any of you biologists? Don't have BA's in History and Women's Studies? Smarter than me? Help a girl out here! Thanks.
I am going to copy just my comments here, since, well, I wrote them and I figured that I didn't need to ask permission to do that. (I did not ask permission to copy his words, so I didn't. Anyway, you can just go to his blog to read them.) I corrected a few typos in my comments in an attempt to save face, but otherwise, it's exactly as it appears on his blog, mistakes and all. Oh, I also added a few Wikipedia links for the heck of it. In my comments, I quoted his questions, so it should be fairly understandable even without P-Life's side of the debate.
The sane thing to do, of course, would just have been to recommend Natan Slifkin's books and to leave it at that. (He is only four years older than I! I had no idea until I looked at the Wikipedia article.) I have a feeling, though, that P-Life will never be convinced of the viability of science, no matter how many of Natan Slifkin's books he reads.
Without further ado...
UPDATED on May 10 to add that P-Life responded to some of my points here.
Above is an excerpt from my post http://shmuzings.blogspot.com/2007/03/progress-notes-on-my-evolving-thoughts.html
Just another later thought I didn’t include on the post was if there is a personal God perhaps his role in the midst of true evolution would be- He’s the one who has the rock fall on the a certain creature and this gives another specials the upper hand in the natural selection process. Maybe He is the one who sends the UV ray that causes the mutation that gives one species a detrimental effect while another gets the mutation that will benefit its species.
So maybe there is some hope for R. Slifkin, that there can be evolution and yet there still be a God beyond an ultimate cause who is still part of the real world (He is certainly part of our mental world!)
A few details in your post that weren't quite right--Cro-Magnons did have clothing, and almost surely had language as well, given their level of culture, and the fact their brains (judging from the shape of their skulls) seem to have been anatomically identical to modern humans' brains. Neanderthals had brains as big as Cro-Magnons/modern humans, even slightly bigger on average, but their cultural level was lower, and their culture didn't develop as fast, relative to the size of their population, so there was probably something different about their brains. Quite possibly they didn't have language, or their linguistic abilities were inferior. I think I have seen arguments that that was the case, based on the shape of the surface of their brains, which matched the shape of the interior of their skulls. I think they did have clothing, though.
The division between the lines that led to humans and to chimpanzees was not between larger and smaller brains, and there is no evidence that the ancestors of humans were more intelligent than the ancestors of chimpanzees, right after that division took place, or for some time afterward. Rather, the division was between walking fully upright all the time, and walking sometimes on all fours as chimpanzees do. Richard Dawkins (who P-Life probably wouldn't like reading, because he constantly throws in gratuitous attacks on religion, although he does explain evolution and natural selection very well) lists 14 different theories as to why it was advantageous for the human line to walk upright, in his book "The Ancestor's Tale." One possibility is that it freed up their hands to carry food, so the males could forage further and bring food back to the females who were stuck at home with the children. Another possibility is sexual selection, which doesn't require any objective advantage to walking upright initially, but only requires a temporary fad that was initiated by someone and caught on. (Read the book to understand for why it then continues to spread. Or I can explain it to you if you want.) In any case, once humans were walking upright, large brains might then have been more of an advantage than they were to chimpanzees, because, for example, they could then invent baskets and carry even more food from even further away. Large brains also have a big disadvantage, viz. more complications in giving birth, and babies necessarily being born in a less developed state (before their heads are too big to fit through the birth canal) and less able to survive infancy. (Carl Sagan points out, in one of his books, that difficulty in giving birth is one of the punishments given to Adam and Chava as a result of their eating the pri etz ha-daat.) So unless there were an advantage that outweighed these disadvantages, larger brains would not have evolved. That could explain why chimpanzees, which didn't walk upright, didn't evolve larger brains than they already had. The environment they were in (jungle, vs. savannah for humans) could also play a role, of course, as you pointed out.
A theory isn't required to make testable predictions about everything, any more than a purported Navi is required to make testable predictions about everything. But where it/he does make testable predictions, the predictions had better come true, or the theory is wrong. (Maybe not completely wrong, but it has to be modified, and if there is no core of reliable predictions that it makes consistently, no one will take it seriously.)