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Chris
12-28-2012, 11:59 AM
Could man adapt to major climate change?


...Scientists had long thought Africa went through a period of gradually increasing dryness — called the Great Drying — over 3 million years, or perhaps one big change in climate that favored the expansion of grasslands across the continent, influencing human evolution. However, the new research instead revealed "strong evidence for dramatic ecosystem changes across the African savanna, in which open grassland landscapes transitioned to closed forests over just hundreds to several thousands of years," researcher Clayton Magill, a biogeochemist at Pennsylvania State University, told LiveScience....

The researchers discovered that Olduvai Gorge abruptly and routinely fluctuated between dry grasslands and damp forests about five or six times during a period of 200,000 years.

...The investigators also constructed a highly detailed record of water history in Olduvai Gorge by analyzing hydrogen isotope ratios in plant waxes and other compounds in nearby lake sediments. These findings support the carbon isotope data, suggesting the region experienced fluctuations in aridity, with dry periods dominated by grasslands and wet periods characterized by expanses of woody cover.

...These findings now shed light on the environmental shifts the ancestors of modern humans might have had to adapt to in order to survive and thrive.

"Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response," Magill said in a statement. "Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes. The result can be increased brain size and cognition, changes in locomotion and even social changes — how you interact with others in a group."

This variability in the environment coincided with a key period in human evolution, "when the genus Homo was first established and when there was first evidence of tool use," Magill said.

@ Erratic Environment May Be Key to Human Evolution (http://www.livescience.com/25793-changing-environment-human-evolution.html)

Chloe
12-28-2012, 12:16 PM
I think the future of human adaptation was pretty well summed up in the movie Wall-E :)

Chris
12-28-2012, 12:18 PM
I think the future of human adaptation was pretty well summed up in the movie Wall-E :)

Haven't seen: Could you give a brief synopsis, no spoilers of course! :-)

Chloe
12-28-2012, 12:29 PM
Haven't seen: Could you give a brief synopsis, no spoilers of course! :-)

Its a great movie, one of my favorites, and super cute too. The earth is trashed and so humans leave it, however, they get so spoiled with technology and instant entertainment that they all become fat and pretty much useless.

Chris
12-28-2012, 12:30 PM
Evolution isn't progressive, it certainly could go either way.

KC
12-28-2012, 12:52 PM
I don't think man can adapt biologically to anthropogenic climate change. Two main reasons: a) man made climate change is said to take place over a much more brief period of time than natural climate change and b) technological adaptations replace the natural selection process.

Our technology moves much faster than any natural selection process and prevents humans with advantageous mutations from being more likely to reproduce than others.

Chris
12-28-2012, 02:09 PM
Good points, KC.

(a) is true but does that mean man cannot adapt. Consider recent reports that climate change is no where near what was predicted--discussion of that somewhere else.

(b) but that technology also assists in man's adaptations and it is also part of man's environment--is this a positive or a negative?

KC
12-28-2012, 02:20 PM
Good points, KC.

(a) is true but does that mean man cannot adapt. Consider recent reports that climate change is no where near what was predicted--discussion of that somewhere else.

(b) but that technology also assists in man's adaptations and it is also part of man's environment--is this a positive or a negative?

Technology is an adaptation and it is part of man's environment, but it makes it less likely that natural selection will take place, since even those with genetic advantages are likely to have offspring.

Deadwood
12-28-2012, 02:31 PM
Technology is an adaptation and it is part of man's environment, but it makes it less likely that natural selection will take place, since even those with genetic advantages are likely to have offspring.


Hmmm

First I wonder if we do not make a mistake in thinking that "natural selection" need take place at all.

Technology, beginning with the harvesting and control of fire has strengthened the gene pool. As humans become more comfortable they tend to breed more.

At the same time, with more food and greater comfort usually comes greater structure in a given society, from tribe to city, creating a more "structured selection" if you will, formal marriages.

one thing biology teaches us is that the human body is very adaptable. In the North American North the populace have lived on fish and whale meat, all heavy in oils. Consequently they carry more body fat than those to the south. And they are highly prone to diabetes.
However, that changes within two to three generations when an Inuit moves into a cosmopolitan culture and adapts to the new nutrients.
And so, no, I doubt man will be seriously environmentally challenged in the future. My fear is economic collapse, the loss of comfortable living in particular as that has created more havoc and loss of life in history than even religion.

Deadwood
12-28-2012, 02:38 PM
Evolution isn't progressive, it certainly could go either way.

Negative evolution was the very basis of the Eugenics Movement of the late 19th and mid 20th century. The primary theme was that the human gene pool was being dragged down by the over-breeding of "inferior races" the classification of which varied from jurisdiction to jurisdiction but generally included East Europeans, Hispanics, Negroes, and, of course, Jews.

It was supported by leading scientists of the day as well as some heavy hitters like Theodore Roosevelt, Woodrow Wilson, Henry Ford, Alexander Graham Bell, Thomas Edison and so forth.

It did not really die, it went deeply underground and disguised after a bit of an embarrassment in the form of some guys in Germany who actually carried out the plan with concentration camps and "showers'

KC
12-28-2012, 02:47 PM
HmmmFirst I wonder if we do not make a mistake in thinking that "natural selection" need take place at all.Technology, beginning with the harvesting and control of fire has strengthened the gene pool. As humans become more comfortable they tend to breed more. At the same time, with more food and greater comfort usually comes greater structure in a given society, from tribe to city, creating a more "structured selection" if you will, formal marriages.one thing biology teaches us is that the human body is very adaptable. In the North American North the populace have lived on fish and whale meat, all heavy in oils. Consequently they carry more body fat than those to the south. And they are highly prone to diabetes.However, that changes within two to three generations when an Inuit moves into a cosmopolitan culture and adapts to the new nutrients.And so, no, I doubt man will be seriously environmentally challenged in the future. My fear is economic collapse, the loss of comfortable living in particular as that has created more havoc and loss of life in history than even religion.Right, my basic argument is that technology has replaced biological evolution as a means of adaptation. Not saying that this is a negative thing, in fact I would say it's more positive than anything.

Chris
12-28-2012, 02:47 PM
Negative evolution was the very basis of the Eugenics Movement of the late 19th and mid 20th century. The primary theme was that the human gene pool was being dragged down by the over-breeding of "inferior races" the classification of which varied from jurisdiction to jurisdiction but generally included East Europeans, Hispanics, Negroes, and, of course, Jews.

It was supported by leading scientists of the day as well as some heavy hitters like Theodore Roosevelt, Woodrow Wilson, Henry Ford, Alexander Graham Bell, Thomas Edison and so forth.

It did not really die, it went deeply underground and disguised after a bit of an embarrassment in the form of some guys in Germany who actually carried out the plan with concentration camps and "showers'

That wasn't really evolution, as it was designed and evolution is not. What I meant by it's not progressive is it's not only not driven by some design but also not directed toward some sort of perfection. It's just adaptation to changing environment, which, with technology, man changes. It's a hill climb with the hills changing shapes and moving around.

Chris
12-28-2012, 02:49 PM
Right, my basic argument is that technology has replaced biological evolution as a means of adaptation. Not saying that this is a negative thing, in fact I would say it's more positive than anything.

OK, yea, I see now. With technology we needn't adapt to higher temps but just turn the A/C up. If the power goes off, we're in trouble.