How could we have stopped evolving?

[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!

So, what explains what has happened to us in all that time? What caused us to build up such a cultural heritage and expand in numbers to fill, indeed, even crowd the Earth?

Social theorists have no concensus on that. Some resort to "meme"s as an "explanation." Others just won't believe it and insist that is can all be explained by some sort of biological evolution going on somehow somewhere.

Why hit our heads against the wall? The explanation is available in
HOME PAGE Natural selection has been occuring between societies---not the races as the Social Darwinists and Sociobiologists claim. Not economic systems as the Marxists claim. It is between religion-bonded entities we call "societies," "cultures" or "civilizations but which are distinct entities that compete with each other for survival.

Of course, religious believers hate that idea because it gives religion a natural cause evolutionary purpose! Natural selection working on religions!

But, hey! lets get at a real explanation of what's going on and skip the spiritualism. If we bothered to figure out what is going on, we might be able to do better. . .

[Buffy]

I responded to your *agenda* elsewhere, but to clarify:

Lack of evolutionary changes or actual speciation among humans is excellent supportive evidence for Eldridge & Gould's theory of Punctuated Equilibrium: stability in species is highly likely in the absence of environmental stresses.

Start a war between the races or religions or whatever else the Social Darwinists wanted to do, and you might end up with such stresses!

Be careful what you wish for!

The most erroneous stories are those we think we know best - and therefore never scrutinize or question,
Buffy

[rockytriton]

Originally Posted by Buffy

stability in species is highly likely in the absence of environmental stresses.

Does that mean with the increased stresses of fear mongering by the politicians and the increased stresses of big brother watching over us that it will trigger a new evolution in mankind? Maybe we will evolve tin hats!

[Buffy]

Originally Posted by rockytriton

Does that mean with the increased stresses of fear mongering by the politicians and the increased stresses of big brother watching over us that it will trigger a new evolution in mankind? Maybe we will evolve tin hats!

Or our ears will go the way of the appendix and we will rely solely on smell to decide who to vote for!

Ninety percent of the politicians give the other ten percent a bad reputation,
Buffy

[orbsycli]

we didn't.

[charles brough]

Originally Posted by Buffy

I responded to your *agenda* elsewhere, but to clarify:

Lack of evolutionary changes or actual speciation among humans is excellent supportive evidence for Eldridge & Gould's theory of Punctuated Equilibrium: stability in species is highly likely in the absence of environmental stresses.

Start a war between the races or religions or whatever else the Social Darwinists wanted to do, and you might end up with such stresses!

Be careful what you wish for!

The most erroneous stories are those we think we know best - and therefore never scrutinize or question,
Buffy

Your academic "doubletalk" confuses me. It seems that you are saying that there has been no actual biological evolution since we became a species (which is the concensus now) because of an absense of environmental stresses. Different societies have had a lot of environmental stress, but as you say, even so, there has been no biological evolution of any significance. And that war between the races might bring about "punctuated" biological evolution.

I agree with all that except that a war among super powers with race-based ideolgies would very easily end in a gigantic population crash and unlikely to produce any evolutionary change.

[CraigD]

Originally Posted by charles brough

… there has been no actual biological evolution since we became a species (which is the concensus now) ..

Before this claim can be accepted, it’s necessary to show that it actually is the consensus of evolutionary biologists that H.Sapiens.S. has not evolved since becoming a species.

Aside from the difficulty of defining a distinct event of “becoming a species”, I don’t think this is the conseusus. For example, as described in this World Science article, and discussed in this hypography thread, scientists such as controversial but well-respected anthropologists Gregory Cochran have proposed that not only has human evolution in the past 200,000 years not slowed or stopped, but that it has dramatically accelerated.

Charles, what support can you present for your claim? Might your impression of the consensus among evolutionary biologists be based on out-of-date data?

[Buffy]

It is very important to distinguish between "evolving" and "speciation": the former, as Craig said, is according to some accelerating, but is limited to morphological changes, while the latter--although also subject to some debate as to its definition--revolves around the ability for two organisms to reproduce: animals of different species normally cannot mate, thus they become distinct gene pools that diverge more rapidly.

I don't believe anyone is arguing that there has been--or even that we are close to--a species split. Normally a significant, long-term separation of populations is required for speciation to occur, and it has been tied to environmental stresses. Moreover, due to the ease of travel and the breakdown of cultural barriers to intermixing between groups, it is likely that this consistency of the specie--not that its not *evolving* but that it is not *splitting* into different species--is likely to continue for some time.

Familiarity breeds contempt - and children,
Buffy

[Boerseun]

Originally Posted by charles brough

...end in a gigantic population crash and unlikely to produce any evolutionary change.

Populations going through bottlenecks like the above example, is the most fertile ground for evolutionary change, and most likely the only instance in which the human race will undergo wholesale evolutionary modification.

As it is now, the human race is simply too big and too well-connected genetically, so that any change (of whatever nature, beneficial or not) will be diluted to oblivion in only a few generations.

[Michaelangelica]

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! .

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.