Posted on 10/05/2011 4:18:19 AM PDT by 1010RD
Even in relatively modern societies, humans are still changing and evolving in response to their environment, new research indicates.
The study was published Monday in the journal Proceedings of the National Academy of Sciences.
The researchers found a genetic push toward younger age at first reproduction and larger families while studying an island population in Quebec. The study used data from 30 families who settled on île aux Coudres, located in the St. Lawrence River outside of Quebec City, between 1720 and 1773.
The researchers analyzed the data from women who married between 1799 and 1940, comparing their family relationships, any social, cultural or economic differences, and the age at which they had their first child. Researchers found that over 140 years, the age at first reproduction dropped from 26 to 22.
The University of Quebec geneticist Emmanuel Milot and colleagues who did the study have reported that though "it is often claimed that modern humans have stopped evolving because cultural and technological advancements have annihilated natural selection, this study supports the idea that humans are still evolving.”
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"What we learn from that population is that evolution is possible in relatively modern times in modern humans," Milot said. "Where it is going to occur and in what ways is a different question."
The study has noted that results show that microevolution can be detectable over relatively few generations in humans and underscore the need for studies of human demography and reproductive ecology to consider the role of evolutionary processes.
There is nothing to distinguish true evolution from societal pressures here.
If they could demonstrate something physical, like earlier puberty while controlling for nutrition status, that would be a little more convincing.
From what I’ve read about pioneer America, the age at first childbirth was lower than it is now.
One last critique, and that is that these researchers were looking at an island; conclusions made about an isolated population cannot be extrapolated to the entire population. They are only pertinent to the isolated population.
Oh, and I do not question that humans are continuing to evolve, nor that we are shaping our evolution. Every time someone has a kid through medical interventions (e.g. “test tube baby” or fertility treatments), they are contributing to decreasing the fitness of the human race. Eventually, we could reach a point where medical intervention for reproduction becomes the norm rather than the exception. There are many other examples about how we are preserving traits not conducive to survival, but to point them out would make me seem heartless.
Your description sounds like human choice, rather than “genetic push.”
Natural selection has been defeated or at least put on the defense as “the excess population” no longer naturally dies off. Natural selection knows no social boundaries as it would take a rich child as quickly as a poor. Yet today children rich and poor who may have died of natural causes decades ago, are living to adulthood. And as emotionally charged as childhood death is, death by natural causes served a purpose. Yet because fewer children die of natural causes, it maybe that support for abortion is in part do to this.
Just a random thought. Now off to work.
Sounds a lot like "If it's hot outside, AGW, if it's cold outside, AGW."
We face a terrible erosion in the sciences. There is a drift from the truth or even a search for it. This ‘study’ was really just someone reviewing the birth records. It is a poorly designed experiment, but the headline will carry the day.
We need vouchers so people can escape government schooling.
Great points, particularly the in vitro reproduction, but also c-sections, etc. There is always some sense that our tech makes life too easy or does it free up physical restraint to allow our brains to improve?
At the same time, as regards birth, much of the above is happening because motherhood is being delayed. In the case of the most liberal they are instead simply passing motherhood by childless. I’m curious to watch the trends as the religious have a major advantage in child bearing. What will be the sociological effects? Will America become balkanized as liberals die out or can government schooling indoctrinate enough children to keep liberalism alive?
Because this tendency can be seen across the species, for example small dogs tend to have larger and/more frequent litters than large dogs, it’s probably built into our makeup.
They’ve been able to show empiracally that if a species moves from a high death rate to a lower death rate, the number of births they give will also drop.
This is news??? There are dozens of studies showing the same pattern of reduced ages to puberty and marriage, etc. in the last few centuries. Dr. Jack Cuozzo would hardly be surprised, he had extensive discussion of them in his creationist book Buried Alive.
Note that this is the opposite of Darwinian expectations. Evolutionists believe we evolved from apes with faster generation times, not slower. It is more consistent with the idea of degeneration from past times when humans lived much longer.
But more likely these kinds of changes have almost nothing to do with genetics at all. Simple dietary (adequate nutrition = no delay of maturation) and cultural changes suffice to explain modest shifts like this.
Have they been able to demonstrate experimentally, with controls, that this is caused by genetic coding rather than by environmental factors?
Hence, the movie “Idiocracy”. . . which seems more and more prophetic every year that passes. . .
http://www.youtube.com/watch?v=YvxNgdFeWqM
I’ve seen them, and they aren’t pretty. And yes, I’m sure at least one of those pictures were taken at a Walmart in my area (the pirate, during a party here in FL we call “Gasparilla”)
http://gasparillapiratefest.com/parade.shtml
Good point, here and in your post 25.
If TSHTF resulting in total societal collapse, the survival of people with life-shortening physical traits, such as severe dietary allergies, may decline, resulting in a lower percentage of the population with such traits.
“141 years is an awfully short time span to ‘evolve’.”
Understatement!!!!!!!!!!!!!!
Calling this evolution is absurd. A little study should show that the age at first childbirth has varied up and down for a long, long time depending on cultural and environmental factors. Nutrition will even play a part. It makes no more sense than saying that longer hair styles are proof of evolution. In my not so humble opinion calling this evolution is totally ridiculous.
Exactly! This is no more proof of evolution than the fact that women are now far more likely to have a university degree is evolution. How could something so utterly stupid be taken seriously?
“There are many other examples about how we are preserving traits not conducive to survival, but to point them out would make me seem heartless.”
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I will volunteer to be heartless in your place. Young people who are so stupid as to have actually voted for our current “president” are allowed to reproduce. Certainly this does not bode well for the future of humanity.
I don’t know, aside from the fact that the same species but in different areas, do have differing birth rates that can be correlated by the species chance of survival is genetic or otherwise.
What I’ve read about genes themselves is that they are responsible for our physiology, but they don’t seem to have much to do with our behaviours. However, there is a, if you will, a subset of genes called epistomological (I probably mispelled it :) ) that does seem to be affected by our behavious and that is where one might be able to trace why behavioural tendencies tend to run in families.
I don’t know, aside from the fact that the same species but in different areas, do have differing birth rates that can be correlated by the species chance of survival is genetic or otherwise.
What I’ve read about genes themselves is that they are responsible for our physiology, but they don’t seem to have much to do with our behaviours. However, there is a, if you will, a subset of genes called epistomological (I probably mispelled it :) ) that does seem to be affected by our behavious and that is where one might be able to trace why behavioural tendencies tend to run in families.
But, but ... they are "researchers" at a government university! They did a Study! They're going to get more funding for more Studies! They can't be questioned by the Lower Orders!
Obviously, humanity is evolving toward its optimal form, the tenured public university researcher.
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