Why aren’t human feet adapted to walking on rough surfaces, say for example, bushland, which is where we “supposedly” came from?
Who says they’re not?
The sole of the human foot is very susceptible to building callouses. People who constantly walk without shoes develop a nice leathery sole that allows them to walk great distances onver fairly rough country. People who protect their feet in shoes all the time only tend to build up callouses on the ball and heel. There are a goodly number of societies where shoes are not worn, even today. I don’t see those people constantly limping or hobbling around on damaged feet by the age of twelve. (If you point out that they do suffer fot damage by age fory–and I do not know that this is actually true anywhere, I will note that by age forty, they will probably have already bred and raised thier children, so evolution has succeeded in getting what it needed out of them.)
Felix, i’ll explain this to you with my limited knowledge on evolution, thanks to the link from Ben. Please correct me if I’m wrong.
Evolution is a change. Did you ever bother to think that we may have changed back seeing that we came from those bushlands…well, quite some time ago. The people in the bushlands still have tough feet. I’d bet money on it.
Felix:
Welcome to Straight Dope. Human feet adapt fairly easily to rough terrain. How do you see your question as bearing upon natural selection?
Native populations the world over go barefoot in most any terrain. The Sherpas of the Himalayas even go barefoot over glaciers carrying heavy packs. I don’t think you have done much research before deciding what the human foot is suited for.
One addition … the original poster may have been asking why human feet aren’t optimized for walking on rough surfaces.
If so, the answer is that evolution is not “globally optimizing” process. Personifying evolutuion (which is of course formally wrong), it has no long term goal or direction. It automatically finds a “local optimum”; what works best here and now.
Human feet are good enough for walking on the surfaces on which we walk.
Well, that was easy.
Got a tough question, Felix?
(Oh, BTW . . . what in tarnation is an “evolutionist?” Is it simply someone who accepts that a preponderance of evidence supports evolutionary theory? Or are there actually still people out there who believe that evolution is a belief system?)
Actually, yes. There are still people who subscribe to Henry Ward Beecher’s theology, of which Darwin’s work is the cornerstone.
What I can never figure out is why the Creator (Intelligent Designer, whatever) gave us an appendix. Doesn’t seem very Intelligent to Design something with no purpose that gets infected and kills you. Unless maybe its purpose is to kill you.
Intelligent Design does not necessarily imply a creation of man fiat ex nihilo. It more often implies a general intelligent design of such things as the laws of physics and natural selection.
Er, as far as I know HWB founded no religions, and no movements. He preached acceptance of evolutionary theory. That doesn’t make evolution a religion or belief system, any more than it makes the other issues he preached–abolitionism, temperance, suffrage–religions.
I just wanted to chime in and point out that not everyone believes that humans evolved chiefly in bushland. The aquatic ape theory states that an important evolutionary precursor to humans was a wading, swimming, fishing hominid which lived near the Indian Ocean and/or the Red Sea, and/or in marshlands and rivers near them.
I hope I summarized that theory pretty well. I don’t know a ton about it, but it is interesting since it attempts to explain a bunch of differences between humans and apes at one fell swoop: apes are thin and furry; we are fat and naked, etc. Anyway, I think human feet would be pretty good for general purpose duties. They are flat, which would be better for wading than hooves or cat/dog feet, which might cause heavy humans to sink into the silt. They are presumably better for walking cross-country (from marsh to marsh, or something) than the comparatively “hand-like” feet of many primates. They are okay for climbing trees, at least comparied to hooves (although chimps have us handily beaten in this regard).
Anyway, I didn’t want the tacit “humans are certain to have evolved exclusively in scrubland” assertion to go unchallenged.
Andros
Beecher didn’t found a religion per se, in the sense that Jim Jones did, but that’s not what I said. His theology was considered highly unorthodox at the time (I feel his pain…) because he presented new ideas about man that were unthinkable without the integration of Darwin’s theories. He wove, or tried to weave, the man of Christ and the man of Darwin together, and presented scripture passages as concurring with evolution. He even saw Paul as a sort of Darwin precursor!
From one of his sermons…
The egyptians thought this of the brain didn’t they?
[sub] well maybe not infected[/sub]
:shrug: I don’t see how drawing a parallel between Paul’s version of the duality of human nature and Darwin’s ideas means that Beecher’s theology was dependent on evolution. There are no ideas in the passage you quoted which require evolution. This is as close as he gets:
So man has a bestial nature, but has the potential for more. He’s not the first to say that, and won’t be the last.
Andros:
From the passage quoted:
You’re so used to evolution that maybe you don’t understand what a jolt it was back then — especially to Christian theologians.
No, I think I understand very well the impact it had. But perhaps we’re reading the line differently. As far as I can see, Beecher is saying:
“Where traditional theologies hold mankind to be divine and far removed from beasts, modern scientific thought holds that we are directly related to animals, developed from animals. Paul holds we have an animal nature. There is a seeming parallel here.”
I cannot see this as suggesting that Paul somehow knew of evolution or was a “Darwinist” (whatever that means); rather, it merely points out that Paul knew that mankind has an animal nature that must be striven against.
(Regardless, I still haven’t seen that any of Beecher’s theology was at all dependent on evolution, much less a cornerstone.)
I’ll try to dig up some HWB sermons tonight or this weekend, but if you can provide any further support for the “evolution as religious tenet” idea, I’d truly appreciate it.
Here’s one from The Center for Theology and the Natural Sciences, as part of an article written by Dr. Francisco Ayala, Professor of Biological Sciences and Philosophy at the University of California, Irvine.
I don’t think he was saying Paul was a Darwinist, but I think he was saying that, contrary to the hysteria in the church over evolution, Paul’s doctrine was not challenged by Darwin.
I meant to add, “and in fact was augmented by it.”
From Dr. Ayala:
OK.
Yup.
Hold the phone. Upon what does Ayala base this? And what does he mean by it?
You said:
Yup, not problems there, either. Lots of folks nowadays believe that evolution does not necessarily contradict Paul. They didn’t in Beecher’s day, true, but that in itself does not make evolution per se a cornerstone of his theology.
(I’m heading home now . . . I’ll be back sometime over the weekend.)
-a-