Study shows humans still evolving
A new study published in the Proceedings of the National Academy of Sciences provides evidence of human evolution and rapid genetic changes suggesting that, contrary to modern claims, technological and cultural advancements have not halted the evolutionary process in humans.
Read below from physorg.com:
October 4, 2011 by Deborah Braconnier
The new study, led by geneticist Emmanuel Milot from the University of Quebec, looked at a group of women from the remote island town of Ile aux Coudres in Quebec, Canada. The team looked at the birth, death and marriage records kept by the Catholic Church in the town. They were specifically looking at the data from women who married between 1799 and 1940.
What they discovered was that within that 140 year time frame, the age that the women conceived their first child dropped from 26 to 22. Looking at cultural, social and economic differences in the women, the researchers were able to determine that 30 to 50 percent of this variation in age was explained solely by genetic variations.
This island town was settled by 30 families between 1720 and 1773 and researchers believe that a genetic change occurred in order to provide more time for women to produce a larger number of children in order to grow the population. While the researchers did not look at which specific genes may have been altered over time, they believe possible reasons could have been a change in the age in which the women hit puberty and heritable personality traits which pushed them to wanting to start families earlier. These changes were a response to natural selection and the need for a higher number of children in order for gene lines to survive into the future.
This is not the first study to show that human evolution is still happening. Recent studies include the Tibetans evolutionary change to adapt to the lower oxygen levels found in their high altitude environment. This change has only occurred throughout the last few hundred generations. Other studies show that humans have only evolved the ability to tolerate lactose in their systems over the last 5,000 or so years.
While many scientists have trended toward the idea that changes in populations are typically due to environmental or social influences in today’s societies, this study shows that while these factors do play a role, genetic changes and evolution are also still very much a part.
The new study, led by geneticist Emmanuel Milot from the University of Quebec, looked at a group of women from the remote island town of Ile aux Coudres in Quebec, Canada. The team looked at the birth, death and marriage records kept by the Catholic Church in the town. They were specifically looking at the data from women who married between 1799 and 1940.
What they discovered was that within that 140 year time frame, the age that the women conceived their first child dropped from 26 to 22. Looking at cultural, social and economic differences in the women, the researchers were able to determine that 30 to 50 percent of this variation in age was explained solely by genetic variations.
This island town was settled by 30 families between 1720 and 1773 and researchers believe that a genetic change occurred in order to provide more time for women to produce a larger number of children in order to grow the population. While the researchers did not look at which specific genes may have been altered over time, they believe possible reasons could have been a change in the age in which the women hit puberty and heritable personality traits which pushed them to wanting to start families earlier. These changes were a response to natural selection and the need for a higher number of children in order for gene lines to survive into the future.
This is not the first study to show that human evolution is still happening. Recent studies include the Tibetans evolutionary change to adapt to the lower oxygen levels found in their high altitude environment. This change has only occurred throughout the last few hundred generations. Other studies show that humans have only evolved the ability to tolerate lactose in their systems over the last 5,000 or so years.
While many scientists have trended toward the idea that changes in populations are typically due to environmental or social influences in today’s societies, this study shows that while these factors do play a role, genetic changes and evolution are also still very much a part.
[via: physorg.com]
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