Humans Evolving Faster. Sorry Creationists!
Sorry all you Creationist Dudes, not only are we evolving, but we are doing so at an ever increasing rate!
Anthropology researchers at the University of Utah have found the pace of evolution has accelerated in the past 50,000 years, especially since the end of the Ice Age 10,000 years ago.
Meanwhile, according to research leader Henry Harpending, a professor of anthropology at the university, Human races are evolving away from each other and are very different from what they were 1,000 or 2,000 years ago,
(That explains, in part, the difference between Viking invaders and their peaceful Swedish descendants.)
The researchers looked for genetic evidence of natural selection, or the evolution of favourable gene mutations, over the past 80,000 years by analyzing DNA from 270 individuals in the International HapMap Project, which is an initiative to identify variations in genes that cause disease.
They studied 3.9 million chromosome mutations from 270 people in four populations: Han Chinese, Japanese, Africa’s Yoruba tribe and northern Europeans, represented largely by data from Utah Mormons. Harpending and his team examined the speed at which chromosome mutations broke up and recombined and found that about seven per cent are undergoing rapid, recent evolution.
The main result of these findings is to deflate the commonly held befief that human evolution has remained static over the last 50-100,00 years said Dr. Harpending.
In fact, people today are genetically more different from people living 5,000 years ago than those humans were different from the Neanderthals who vanished 30,000 years ago, according to anthropologist John Hawks of the University of Wisconsin.
Human migration into new environments has also led to adaptations to colder weather, such as less skin pigmentation to allow for more vitamin D absorption.
The genetic changes have related to numerous different human characteristics, the researchers said.
Many of the recent genetic changes also reflect differences in the human diet brought on by agriculture, as well as resistance to epidemic diseases that became mass killers following the growth of human civilizations, the researchers said.
For example, Africans have new genes providing resistance to malaria.
In Europeans, there is a gene that makes them better able to digest milk as adults.
In Asians, there is a gene that makes ear wax more dry.
The changes have been driven by the colossal growth in the human population -- from a few million to 6.5 billion in the past 10,000 years -- with people moving into new environments to which they needed to adapt, added Henry Harpending, a University of Utah anthropologist.
Even with these changes, however, human DNA remains more than 99 percent identical, the researchers noted.
Genes have evolved relatively quickly in Africa, Asia and Europe but almost all of the changes have been unique to their corner of the world. This is the case, he said, because since humans dispersed from Africa to other parts of the world about 50-100,000 years ago, there has not been much flow of genes between the regions.
Allan W Janssen is the author of The Plain Truth About God at www.God-101.com and the blog "Perspective" at http://God-101.blogspot.com
Anthropology researchers at the University of Utah have found the pace of evolution has accelerated in the past 50,000 years, especially since the end of the Ice Age 10,000 years ago.
Meanwhile, according to research leader Henry Harpending, a professor of anthropology at the university, Human races are evolving away from each other and are very different from what they were 1,000 or 2,000 years ago,
(That explains, in part, the difference between Viking invaders and their peaceful Swedish descendants.)
"The dogma has been these are cultural fluctuations, but almost any temperament trait you look at is under strong genetic influence," Harpending said in a release.The findings were published in Monday's edition of the Proceedings of the National Academy of Sciences.
The researchers looked for genetic evidence of natural selection, or the evolution of favourable gene mutations, over the past 80,000 years by analyzing DNA from 270 individuals in the International HapMap Project, which is an initiative to identify variations in genes that cause disease.
They studied 3.9 million chromosome mutations from 270 people in four populations: Han Chinese, Japanese, Africa’s Yoruba tribe and northern Europeans, represented largely by data from Utah Mormons. Harpending and his team examined the speed at which chromosome mutations broke up and recombined and found that about seven per cent are undergoing rapid, recent evolution.
The main result of these findings is to deflate the commonly held befief that human evolution has remained static over the last 50-100,00 years said Dr. Harpending.
"Our study denies the widely held assumption or belief that modern humans appeared 50,000 years ago, have not changed since and that we are all pretty much the same," he said. "We show that humans are changing relatively rapidly on a scale of centuries to millennia, and that these changes are different in different continental groups."The researchers noted that rapid population growth, along with big changes in culture and ecology, have resulted in major genetic changes, such as skeletal and dental changes.
In fact, people today are genetically more different from people living 5,000 years ago than those humans were different from the Neanderthals who vanished 30,000 years ago, according to anthropologist John Hawks of the University of Wisconsin.
Human migration into new environments has also led to adaptations to colder weather, such as less skin pigmentation to allow for more vitamin D absorption.
The genetic changes have related to numerous different human characteristics, the researchers said.
Many of the recent genetic changes also reflect differences in the human diet brought on by agriculture, as well as resistance to epidemic diseases that became mass killers following the growth of human civilizations, the researchers said.
For example, Africans have new genes providing resistance to malaria.
In Europeans, there is a gene that makes them better able to digest milk as adults.
In Asians, there is a gene that makes ear wax more dry.
The changes have been driven by the colossal growth in the human population -- from a few million to 6.5 billion in the past 10,000 years -- with people moving into new environments to which they needed to adapt, added Henry Harpending, a University of Utah anthropologist.
"The central finding is that human evolution is happening very fast -- faster than any of us thought," Harpending said in a telephone interview. "Most of the acceleration is in the last 10,000 years, basically corresponding to population growth after agriculture is invented," Hawks said in a telephone interview.Beneficial genetic changes have appeared at a rate roughly 100 times higher in the past 5,000 years than at any previous period of human evolution, the researchers determined. They added that about 7 percent of human genes are undergoing rapid, relatively recent evolution.
Even with these changes, however, human DNA remains more than 99 percent identical, the researchers noted.
Genes have evolved relatively quickly in Africa, Asia and Europe but almost all of the changes have been unique to their corner of the world. This is the case, he said, because since humans dispersed from Africa to other parts of the world about 50-100,000 years ago, there has not been much flow of genes between the regions.
Allan W Janssen is the author of The Plain Truth About God at www.God-101.com and the blog "Perspective" at http://God-101.blogspot.com
Labels: creation science, creationism, evolution, science
posted by Allan W Janssen | 7:51 a.m.
5 Comments:
What I find interesting is that although the mutation rate must indeed be changing a great deal as the population explodes, the entire process of natural selection (the other pillar of evolution) has taken nothing short of a radical shift over the course of human civilization. Threats to human survival become more and more a function of social behavior than of any specific physiological mutation. The only area that remains arguably consistent is disease...and it isn't hard to imagine that this too would eventually fall (more completely) under the influence of social dynamics.
The ability to share knowledge, support research and development, and foster technological innovation are the reasons that the population has exploded as it has...and they themselves have largely supplanted the conventional vessels of natural selection (predation, starvation, procreative failure) as potential threats. Phyisiological mutations that cannot be suitably deemed "advantageous" are generally allowed to flourish in a way that historical evolution has not typically allowed.
My point is that although we may be experiencing advantageous mutations at a much higher rate, the definition of "advantageous" becomes elusive...as our singularly relevant trait (intellect) becomes both our sole threat and our only salvation.
I would argue that the population is actually devolving. Conditions and genetic traits that were once barriers to reproduction are now managed to allow for the reproduction of these individuals. Therefore, the undesirable traits are then passed on to future generations and remain in the population indefinitely.
I too, have thought about this, and there might be something to your argument.
After all it is no longer the "survival of the fittest!
"I would argue that the population is actually devolving."
There is no such thing as de-evolution. Evolution doesn't go backwards because there wasn't a forward. There is no goal that evolution is trying to reach other than seeing that genes move from one generation to the next. The mention of "undesirable traits" means a very different thing to selection pressures. If the traits didn't lead to the individual not being able to reproduce in the environment, then there was nothing about them to select against. Just because we alter the natural environment to meet our needs now doesn't mean that there isn't still a world outside of our bodies that our genes have to compete in.
Survival of the fittest has never been the accurate description of evolution. It's survival of the fit enough.
Although there certainly is still a world outside of our bodies that our genes have to compete in, the nature of that competition has changed dramatically with the advent of civilization in that we've begun to exert various degrees of control over the contact our bodies have with that world. As you extrapolate this ability to manipulate the relationship between our bodies and their environment, natural selection is eventually neutralized. You are right in that it is survival of the "fit enough" but as more and more genetic variations begin to fall under that category and are propogated, evolution no longer takes place as is it conventionally defined.
The only trait that begins to have any real relevance is our ability to socialize. In theory, human civilization could reach a point where natural selection would only occur when this behavioral trait expresses itself in a manner that removed individuals from the gene pool. Of course the concept of allowing the removal of individuals from the gene pool complicates things a bit.
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