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, B)

Buffy

[rockytriton]

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! :rolleyes:

[Buffy]

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! :rolleyes:

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

 

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

Buffy

[Queso]

we didn't.

[charles brough]

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! :doh:

 

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]

… 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?

Edited June 19, 2011 by CraigD
Fixed broken post link

[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, :doh:

Buffy

[Boerseun]

...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]

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.

[charles brough]

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?

 

My soucre was: In March 2007, Cochran/Hawks in World Science reported that the main genetic changes have merely been a slight shrinking of body and brain size and changes in metabolism! Don't you think that is unlikely to explain the growth of the human cultural heritage? If it is, then it assumes the different societies located on and in certain races are superior to others and that they evolve superior and then devolve in line with the rise and fall of civilizations!

 

"Experts" will not explain natural selection as working on religion-bonded societies because that would give religion an evolutionary natural cause explanation and lead to a lot of bitter religion-science controversy. Do you really think social science theory is OBJECTIVE?

[CraigD]

My soucre was: In March 2007, Cochran/Hawks in World Science reported that the main genetic changes have merely been a slight shrinking of body and brain size and changes in metabolism!

The article in question states

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.”

and

The traditional picture of humans as a finished product began to erode in recent years, scientists said, with a crop of studies suggesting our evolution indeed goes on. But the newest investigation goes further. It claims the process has actually accelerated.

Although it does state

Hawks and Cochran said some of the most notable physical changes in humans have been ones affecting the size of the brain case.

it continues immediately

A “thing that should probably worry people is that brains have been getting smaller for 20,000 to 30,000 years,” said Cochran. But brain size and intelligence aren’t tightly linked, he added. Also, growth in more advanced brain areas might have made up for the shrinkage, Cochran said

and

“A constellation of features” changed across the board, Hawks and Cochran wrote in their presentation.

In short, I don’t find that the research and speculation presented in this article supports the OP’s claim

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

that is, that there is a scientific consensus that there has been no biological evolution of humans in the past 200,000 years. Rather, is suggest the opposite, that biological evolution of humans has been greater in the past 10,000 years than it was in the hundreds of thousands of years prior to 200,000 years ago.

[Queso]

theres the crescendo!

[charles brough]

Sorry to disappoint you both but you did not read the article to the bitter end. I did. I kept reading it because it kept on blabbing about their great findings without saying what they did find. I had to wade through all of that to reach the final dull end and there it finally was: slightly smaller skeletal and brain case with slight changes in metabolism.This goes not all the time. Everyone wants to see evidence we are still evolving biologically and the Science magazines are eager to supply it.* So, this explains the sorry way that article was written.

 

I would have warned you had I thought you were going to go to all that trouble to discredit me!* What gives us the illusion of biological evolution is the epigenetic changes that occur like in our society when we eat to much, keep the misfits alive, don't get enough exercise, etc.* All that epigenetic damage is eventually errassed by the down cycle of hardship societies eventually undergo.

[Rade]

I do not see the possibility that humans (Homo sapiens) will "evolve" physically into a new species of Homo in the future, not on earth. At one time in the past, there were different species of Homo coexisting, but our species won the game--we are the only ones standing. Thus, we know that in the past, there was an evolution into different species within our genus Homo, that is, we know that Homo sapiens evolved. However, with modern breakdown of racial isolation and commingling of racial gene pools over the next few thousand years, the possibility that Homo sapiens will itself evolve into a new species (on earth) is close to 0.0 %. But this is not unusual, many, many species, once evolved undergo stasis--they become evolutionary dead ends. Homo sapiens is such a species, we are a dead end, a branch on the evolution tree now branched challenged. Not a good thing or a bad thing, just a fact of reality.

 

I do, however, see one possibility of physical evolution for humans dealing with future space colonization. It is possible that a breeding and isolated colony of Homo sapiens on another planet or space-station society could become isolated genetically such that physical evolution (perhaps via genetic drift or/and mutation) could occur, and result in speciation into a new species of Homo.

 

There are two additional types of human evolution possible in the future other than physical--intellectual and social. It has been said that intellectual evolution results in the fittest being the most rational, and that social evolution results in the fittest being the most ethical. I see a future possibility that humans will learn how to produce genetic "good mutations" that will result in increased use of reason in offspring in such a way as to maximize the most ethical behavior toward other humans (that is, I hold to hope that Homo sapiens will, in the future, find a genetic engineered method to break the obnoxious social evil coined--man's inhumanity to man), for I hold such behavior to have genetic basis evolved from our primate origins. So, sorry John, love is not all we need, it just will not do, all we need is reason, and love will follow.

[InfiniteNow]

I do not see the possibility that humans (Homo sapiens) will "evolve" physically into a new species of Homo in the future, not on earth.

Your lack of vision does not necessitate a lack of possibility.

[CraigD]

Sorry to disappoint you both but you did not read the article to the bitter end.

Yes, I did read the article to the end. Reading brief articles completely before commenting on them is a habit that was drilled into me in elementary school, though I do occasionally get hurried and fail to follow it. This article was discussed about 9 months ago, so I’m fairly familiar with it, and other work by and about Gregory Cochran.

Everyone wants to see evidence we are still evolving biologically and the Science magazines are eager to supply it.

From what evidence do you conclude, Charles, that “everybody wants to see evidence that we are still evolving biologically”?

 

One of the point of the World Science article appeared to me to be nearly the opposite – that for many years, scientists and laymen assumed that we were not evolving biologically, but, in light of increased understanding of molecular genetics and interpretation of it by anthropologists such as Cochran, this view is not longer widely held by people familiar with popular and professional biology and anthropology literature. The old status quo, which we could say people “want to believe”, is no longer accepted.

I would have warned you had I thought you were going to go to all that trouble to discredit me!

Please accept my apology if I gave the impression that I meant to personally discredit you. Rather, I sought to show that your statement that “there has been no actual biological evolution since we became a species … is the consensus now” is incorrect, and help dispel mistaken conclusions you may have drawn from this assumption. For example, this implied claim

What gives us the illusion of biological evolution …

(that biological evolution is not actually occuring, but rather is an illusion) appears to me to result from your belief that it’s the consensus of evolutionary biologist that there has been no biological evolution in humans in the last 200,000 years, which is not true.

 

This is the alternative theories forum, so perhaps you intend to present a theory radically opposed to the mainstream consensus of evolutionary biology. Supporting the extraordinary claims made by such a theory, however, requires extraordinary evidence – it can not simply proceed from the claim that mainstream science already accepts its claims, which has been amply shown, IMHO, to be false.

 

As some of the most rigorous methods available to evolutionary biology now involve bioinformatics, it’s necessary to present an alternative explaination of the diversity of genes known to exists in the human population, and the observed rate of genetic change.

I had to wade through all of that to reach the final dull end and there it finally was: slightly smaller skeletal and brain case with slight changes in metabolism

The argument that some of the visible consequences of genetic change, such as smaller size and changes in metabolism, are intuitively too minor to be considered true evolution, is, IMHO, unconvincing, and not shared by most evolutionary biologists.

 

I, too, was un-awed by the writing style of the World Science article. However, poor writing style does not discredit the theories presented in a science article.