How could we have stopped evolving?

[Michaelangelica]

Originally Posted by nutronjon

I don't think Cochran/Hawks in World Science report is correct about our evolution stopping.

I agree

Although there may be atrait or two in the oldest continuous religious goup on earth- Judaism
It may be that there are some metabolism differences. I believe, for example, that coeliac disease is more prevalent among Jewish people as it is with Irish (Celtic ) peoples.

[CraigD]

Originally Posted by nutronjon

I don't think Cochran/Hawks in World Science report is correct about our evolution stopping.

Though I can see how one would get the impression from posts such as the first in this thread:

Originally Posted by charles brough

In March 2007, Cochran/Hawks in World Science reported that the main genetic changes that have taken place in us in the last almost 200,000 years have merely been a slight shrinking of body and brain size and changes in metabolism!

An actual read of the World Science article “Human evolution, radically reappraised” reveals that it reports a claim almost exactly the opposite of the claim that human evolution has stopped. The first sentence of the article reads

Human evolution has been speeding up tremendously, a new study contends—so much, that the latest evolutionary changes seem to largely eclipse earlier ones that accompanied modern man’s “origin.”

I’m puzzled how charles brough interpreted the article as a claim that humans have stopped evolving, though I believe his reasoning has something to do with the difficult-to-precisely-define biological term “species”, and the not unreasonable belief that biological evolution in humans has become less significant in many ways than changes in human society.

It’s wise, I think, to reread a source before repeating conclusions made about it. In this case, we appear to have twisted our impression of the article in question to almost the exact opposite of its actual message!

[nutronjon]

Well good.

Last night's show about starvation around the world, is so pressing on me at the moment, it seems silly to argue the evolution issue, so I am glad there is no serious arguement going on here. The only reason I get involved in such arguments, is to oppose superstitious notions, so we can get down to the work that really needs to be done.

[PocketLint]

Having very, very poor eyesight and very very large glasses to correct the situation, I have often wondered how I would have survived during the era(s) where our species experienced vast changes in our biological features.


There would have been no Lens Crafters to help me see. I could not have hunted my own food. I would have been a burden on any 'clan' to feed. I would have passed on long before I could sire any children, who would most likely inherit my poor eyesight based on the fact that my 4 kids current wear glasses also.


So, bouncing around in the back of my head is the idea that mankind's ability to harness technology has played a very large role causing our evolutionary changes to plateau.


-Bob

[Michaelangelica]

Originally Posted by PocketLint

So, bouncing around in the back of my head is the idea that mankind's ability to harness technology has played a very large role causing our evolutionary changes to plateau.


-Bob

There is a lot of archaeological evidence that injured humans (broken bones, arrow wounds (with the arrow head still in situ) ,trepanned skulls, arthritis) were cared for by early humans and I think Neanderthals too.
So the evolution of a caring society changed evolution?

You may have been the Monet of the tribe?
(The world looks like one of his paintings to me without my glasses)

[PocketLint]

Originally Posted by Michaelangelica

There is a lot of archaeological evidence that injured humans (broken bones, arrow wounds (with the arrow head still in situ) ,trepanned skulls, arthritis) were cared for by early humans and I think Neanderthals too.

I was referring to genetic issues more than environmental. It's not inconceivable to me that someone with a broken arm might get cared for as they will eventually be able to function again in some capacity.

What about the person with diabetes or inherited heart valve issues they would surly die out long before their genes could be passed on to later generations with or without societal care.

I guess survival of the fittest kind of thing. For the most part, we no longer have that mechanism as one of the cogs of evolution in play.

Don't get me wrong. I'm in no way suggesting this is a bad thing. I would not want to exist in a society that did not care for it's infirm.

I was just trying to answer the original question. "How could we have stopped evolving?'



-Bob

[Moontanman]

Originally Posted by Michaelangelica

I don't think this is true.
There have been a number of genetic changes in the last 10,000 years.
EG:-
1. Ability to digest lactose
2 Loss of ability to manufacture Vitamin C
3. Among those who live in high altitudes, the ability to access oxygen more efficiently.
5. The ability to digest gluten.
6. Resistance to many diseases such eg AIDs, due to exposure to c 10-15C plague virus. Also small pox and measles resistance among Europeans.

While I am not sure about the other things you are proposing strike the vitamin C thing. All great apes share this trait with us and it almost certainly evolved several million years ago.

[DFINITLYDISTRUBD]

We ain't done evolving...
Humans will get smaller and dumber in a few thousand years or so...A direct result of having machines do all the thinking and remembering for us and our insatiable need and love of mechanised transport...size and smarts simply won't be needed so with lack of use for a few few generations

[CraigD]

Originally Posted by PocketLint

So, bouncing around in the back of my head is the idea that mankind's ability to harness technology has played a very large role causing our evolutionary changes to plateau.

Take care to read the actual March 2007, Cochran/Hawks in World Science from which the original post of this thread drew the conclusion that humans have stopped evolving. In particular, note that it begins:

Human evolution has been speeding up tremendously, a new study contends—so much, that the latest evolutionary changes seem to largely eclipse earlier ones that accompanied modern man’s “origin.”

Rather than supporting it, Cochran and Hawks’s research suggests almost exactly the opposite of a present-day plateau in human evolution.

Originally Posted by PocketLint

Having very, very poor eyesight and very very large glasses to correct the situation, I have often wondered how I would have survived during the era(s) where our species experienced vast changes in our biological features.

There would have been no Lens Crafters to help me see. I could not have hunted my own food. I would have been a burden on any 'clan' to feed. I would have passed on long before I could sire any children, who would most likely inherit my poor eyesight based on the fact that my 4 kids current wear glasses also.

Rather surprisingly, there appears to have been little detailed research of the genetics of nearsightedness. As far as I can tell, this 2005 “gene scan” study is the first broad study of it, and is very preliminary. This is less surprising when one considers that, compared to other heritable disorders, such as diabetes, nearsightedness has very little lethality, and, as wearers of very thick glasses and recipients of radial keratomy surgery know, can be very effectively managed.

The preliminary research indicates that, as was expected from empirical observations, nearsightedness involves many genes, with complicated dominance-recessiveness characteristics, so it’s unclear how common it was among prehistoric, or even historic humans up prior to fairly recent times. It’s also unclear how important to survival and reproduction good eyesight was among prehistoric humans – unlike the literacy requirements of recent industrial and “information age” society, one can argue that ancient hunter-gatherer society required little more from many of its members than the ability to perceive large objects at close range, a good sense of smell, taste, and touch, and appropriate cognitive and memory skills. It’s even reasonably to speculate that poor vision might have resulted in early social specialization, as humans unable to see well enough to run and hunt assumed “high tech” roles of a more intellectual nature (ie: “cave geeks” ). If this was the case, bad-eyesight genes may actually have had an important positive effect on our species survival and growth, and been selected for, not against.

[DFINITLYDISTRUBD]

one can argue that ancient hunter-gatherer society required little more from many of its members than the ability to perceive large objects at close range, a good sense of smell, taste, and touch, and appropriate cognitive and memory skills.

So us farsighted folks must have been the lookouts..eh?
(You'd think there'd be more of us than even normal sighted folk as we could see the various large carniverous critters comin to dinner alot sooner)