Europeans have ‘got whiter’ due to natural selection in past 5,000 years, scientists say
Experts have found a few
changes in European DNA due to natural selection. These changes have made
skin’s European humans to become much ‘whiter’ through the last 5,000 years.
Recently, there has been a research based on the comparison of ancient and current
DNA. The study has shown a genetic distinction between our ancestors and us.
This difference, due to its relation with hair, eye pigmentation and skin, has
caused the descendants to be ‘whiter’.
The results were not the ones
scientists expected as in theory darker phenotype has always had preference
over whiter phenotype. The surprising result has lead to several explanations.
Mark Thomas UCL’S professor
has said that this change over the past thousand years could have been a
natural adaptation to reduction in the amount of sunlight received in northern latitudes.
Sandra Wilde, the lead report
author from Mainz’s Johannes Gutenberg University, gives us another possible
explanation. This explanation could be related to group affiliation, as the
change on the hair and eye colour might have an important role in the selection
of a partner.
However, there is a last
explanation that says that this result could be connected to a specific
timeframe. While archeologists are trying to find the exact point when this
distinction in our genome happened, researches discuss about what could have
provoked this change. The final conclusion that they reached is that all this
may be caused by positive selection.
I have chosen this article
because the title appealed to me so much. I still continuo without
understanding why natural selection had chose whiter phenotype, as being whiter
makes us more vulnerable to ray of sunlight. Experts have concluded that this
lighter skin is due to the reduced level of sunlight in northern areas. However,
climate change is producing an increase of temperatures and also an increase in
the amount of sunlight received, so I think that there would be another
timeframe where the darker phenotype would take preference again.
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