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Humans altering genetic diversity of insect, fish populations across the globe

By Brooks Hays
New research showed human density changes had the largest impact on the genetic diversity of insect populations. Photo by Patrick Timmons/UPI
New research showed human density changes had the largest impact on the genetic diversity of insect populations. Photo by Patrick Timmons/UPI | License Photo

Oct. 22 (UPI) -- Human-caused environmental changes are inspiring genetic changes in thousands of species of birds, fish, insects and mammals across the globe, according to a new study.

Scientists at McGill University in Canada surveyed data collected from the largest genetic databases available. The researchers analyzed 175,000 genetic sequences, comprising the DNA of 27,000 populations of 17,082 different animal species.

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For their analysis, scientists organized each sequence both spatially and temporally in order to determine whether human-related impacts produced temporal trends in genetic diversity.

According to the study's authors, previous studies have failed to analyze the spatial and temporal components of genetic change.

"This is currently our best estimate of how humans are impacting animal genetic diversity worldwide," Katie Millette, a doctoral candidate in the biology department at McGill, said in a news release. "We found that there is an effect of humans on animal genetic diversity, but it is a matter of species and spatial scale because we found nearly equal instances of increasing versus decreasing trends."

Scientists found the largest human-caused impacts on genetic diversity were experienced by insect and fish populations. Specifically, the data showed increases in human density were associated with declines in genetic diversity among insect populations, and that land-use changes resulted in declines in genetic diversity among fish populations.

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The team of researcher published the results of their analysis this week in the journal Ecology Letters. The study's authors suggest more data collection is needed to fill in knowledge gaps and improve scientists' ability to identify the causes of worldwide temporal changes in species genetic diversity.

"The loss of genetic diversity will hinder the ability of plant and animal populations to adapt to changing environments," said McGill biology professor Andy Gonzalez. "We need to monitor the genetic diversity of wildlife so that we can understand better where, when and why it is declining in some places and increasing in others."

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