Text 564, 154 rader
Skriven 2004-10-28 16:46:00 av Erwin Moller (1:278/230)
Ärende: Re: Can evolution go back
=================================


Larry Moran wrote:

> On Tue, 26 Oct 2004 05:47:39 +0000 (UTC), Catherine Woodgold
> <an588@freenet.carleton.ca> wrote:
> 
>> Erwin Moller
>> (since_humans_read_this_I_am_spammed_too_much@spamyourself.com) writes:
> 
>>> One sidenote: For evolution to work you need environmental pressure.
> 
> This is not correct. Populations will evolve even if the environment is
> perfectly stable. There are two important reasons why this is so. First,
> a large part of evolution is due to random genetic drift and
> "environmental pressure" is irrelevant for this mechanism of evolution.
> Second, no species is perfectly adapted to its environment. There's always
> room for further adaptation. (Do you know of any species that has stopped
> evolving because it has become perfectly adapted to its present
> environment?)


Ok Larry, if you interpret my words to the letter you are right, of course.
I know evolution is happening all the time.
The question is if it is going in a direction we think is good.

I am also very aware we have in our modern world other pressures than 
before. No discussion there.

What I ment was simply this:

Because of medical care we can let all kind of bad genes prosper in the 
genepool. 

With bad genes I mean genes that carry some disease.
What is a disease? I don't know, lets just name it anything that makes your 
body function less or not.
We can go into details and definition, which is not very interesting at this 
point IMHO.

In a harsh world without medical care, these individuals have little to none 
chances to survive, depending on the disease.

When we let medical care polish away those symtoms, the individuals survive 
and have offspring.
In that way these disease-carrying genes will be found more in the genepool.

I, for example, need -6 glasses to correct for my bad vision. 
What would me chances be to survive 10.000 years ago?
I think quite bad.
So I am really happy with medical care. 
I don't know how much genes are involved (direct and indirect) to develop 
eyes, but it must be a bunch.
Nowadays pressure falls away on selecting for good working genes for eyes.

Before you start shouting names like Nazi, let me clarify: 
I am not offering a solution, nor giving a moral verdict. I was just stating 
that this is a result of medical care.

This is not happening with all the genes of course. It is only happening to 
genes involved in thing we can polish away with medical care.

> 
>>> We humans have a way of making our complete environment to fit our
>>> needs. We also take care of all sick fellowhumans with medical care.
>>> 
>>> I am not oposing to that (being human myself), but it reduces the
>>> environmental pressure a lot by the use of our technology. In a certain
>>> sense we are so on top of our environment, that our evolution slows
>>> down. Ironical, isn't it?
> 
> What's "ironical" is that your conclusion is completely wrong.

Is it?
Why?

> Because of
> advances in medicine etc. we are causing the rate of human evolution to
> speed up, not slow down. In the past, certain individuals with genetic
> diseases (for example) would be eliminated from the population because we
> didn't have the technology. Today (in industrialized countries) these
> individuals survive and reproduce. Thus, the genes they carry have a
> chance of spreading in the human population and this is what evolution is
> all about.

Aha, that explains our misunderstanding.
I think it is you who has poor understanding of what evolution is all about.

You wrote: "Thus, the genes they carry have a chance of spreading in the 
human population and this is what evolution is all about."

That is a really strange way of looking at evolution.
You think that spreading genes, good ones or bad ones, into the genepool is 
what evolution is all about.
With 'good and bad' in this context in mean: building individuals that are 
more or less healthy.

You could make a case that having bad eyes is a nor a good thing, nor a bad 
thing because we have glasses and operation to correct this nowadays.
Which is true.
We don't have much natural pressure on good functioning eyes.
But in my view this creates a dependency on the medical care, that only gets 
bigger with the generations.

> As a general rule, when negative selection is relaxed evolution
> speeds up.
> 
> Your conclusion seems to be based on a misunderstanding of evolution. You
> focus too much on positive natural selection as a mechanism of evolution
> and you assume that we have become so well-adapted our present environment
> that further adaptation isn't happening.

No, I do not think that.
No matter what environment, no matter what technology, the ones that make 
the most offspring in that certain situation, will be the most succesfull 
in the sense that they/those genes will be in the majority.


> 
>> Just because we have medical care doesn't mean we're
>> not evolving.  For one thing, medical care can only do
>> so much.  Vitamins have much more effect on health and
>> length of life IMO.  Anyway, we are evolving to promote --
>> what?  intelligence?  A collection of humans that incluces
>> a minimum number of creative people?  A collection of
>> humans who care about each other -- or who don't care?
>> People who are careless about birth control, or who
>> love children?  There are environmental pressures --
>> just different ones from before.
> 
> Cathy, you also seem to be focused on positive natural selection as the
> only significant mechanism of evolution and you seem to accept the idea
> that we have no room for adaptation to our present physical environment.
> You shouldn't have conceded Erwin Moller's conclusion since it's
> incorrect.

according to Larry.

> 
> 
> 
> 
> Larry Moran


Regards,
Erwin Moller
---
ū RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info@bbsworld.com

---
 * RIMEGate(tm)V10.2á˙* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 10/28/04 4:46:09 PM
 * Origin: MoonDog BBS, Brooklyn,NY, 718 692-2498, 1:278/230 (1:278/230)