Re: Help on honest questions
- From: Timberwoof <timberwoof@xxxxxxxxxxxxxxxxxx>
- Date: Fri, 30 Dec 2005 02:56:30 -0800
In article <1135937802.618458.82260@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"A. Grace Haliburton" <kaosgrace@xxxxxxxxx> wrote:
> I'm having a discussion with a friend about the origin of life,
> evolution and natural selection. He's asked several honest questions
> which I don't seem to be able to answer very effectively; I know the
> answers but don't know how to make them convincing and understandable
> in spoken dialogue. Some are common cretinist questions, but he's miles
> away from being a cretinist so please give him the benefit of the
> doubt.
>
> 1. If humans evolved from apes, why are there still apes? (think I got
> this one with the common ancestor explanation, but if there's anything
> further I could add please do tell me)
Various populations of our ancestors' species experienced different stresses, so
they evolved differently. Consider the many different breeds of dogs. Border
collies were bred from ... dogs ... and so were mastiffs and beagles. So why are
there still ... dogs? (And wolves, for that matter.)
> 2. Aren't all mutations bad? (only answer I could come up with was flat
> "No")
Well, no, they're not. Imagine a mutation that caused some new color-sensing
protein to be formed in the eye, which gave its owner the ability to see the
color spectrum with better resolution than we can. For instance, one form of
dichromatism [red-green color-blindness] arises from a lack of one of the
color-sensing proteins. It stands to reason that there could be more proteins
than our three, and so we'd have more primary colors. (Well, some would see that
as a disadvantage because we'd have to redesign all our TVs, monitors, and film
and printing processes.)
Imagine a mutation that would make one able to run faster... That's good.
Imagine a mutation that makes men more sociable with other men. That's good for
the species. That's the difference between bonobos and chimpanzees, by the way,
and another answer to question 1.
> 3. Why are we the only intelligent species? (when I pressed him on this
> one, it seems he meant mostly self-awareness, high-level language,
> ethics, philosophy and such; I had no response, since most discourse
> I've read on the evolution of intelligence focuses on the relation
> between bipedal locomotion and toolmaking)
Does he mean on Earth? A detailed study of the history of life on this planet
suggests that it took a remarkable confluence of existing species and changes in
environment to give our ancestors the final evolutionary kick into sentience.
One interpretation has it that we're lucky to be here.
And given how quickly we spread over the whole planet, and how we tended to
suppress or enslave any less-advanced people we met later, it stands to reason
that had humans met another species with intelligence like ours, we would have
seen them as competitors and probably eventually wiped them out. There is
speculation that that's what happened to Neanderthal: Cro-Magnon wiped them out.
(BTW, Neanderthal means "Neander Valley" and Cro-Magnon is the name of a hotel
and restaurant where some anthropologists ate dinner a lot.)
> 4. Why hasn't life evolved on other planets? (explained that the only
> other planets near us are hostile to life as we know it)
Well, there you go. Also consider that we've only recently been able to send
spacecraft there to look, and we haven't even come close to visiting any other
solar systems.
> 5. Why haven't we been able to create life (read: abiogenesis) in the
> lab? (response: just you wait?)
We've been at it for only fifty years with maybe a hundred gallons of goo. The
Earth had the whole of its surface and millions of years to try. I suspect that
we don't understand it fully yet. Like you said; give it time. Nobody ever
pretended that science knows everything.
> 6. Why don't we see things (read: complex vertebrates) evolving? Why do
> we have the same animals around now that were written about by the
> ancient Egyptians etc.?
Well, we do see things evolving, if slowly. Dogs evolved from wolves over the
past fifty thousand years or so; we've only written about them in the past five
thousand or so. Corn used to grow and spread by itself, but because of selective
breeding, the best eating corn is now incapable of spreading its own seed. And
bacteria have evolved under the stress of antibiotics into strains resistant to
them.
> 7. Haven't humans stopped evolving? Aren't social programs and modern
> medicine just fighting natural selection?
For both these questions, consider the time scale of evolution. It takes a long
time for a species to differentiate into another one. Have humans stopped
evolving? I dunno. Come back in half a million years and see. As for social
programs and medicine, absolutely they are affecting which humans reproduce.
> Please help? I need to somehow give solid, accurate answers in language
> no more complicated than the wording of the questions.
I hope I have helped.
--
Timberwoof <me at timberwoof dot com> http://www.timberwoof.com
.
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