Uncovering the underlying patterns in contemporary evolution
Evolutionary impacts of pollution and human harvesting highlighted by new global dataset

Date:
January 19, 2022
Source:
McGill University
Summary:
Wild populations must continuously adapt to environmental changes
or risk extinction. For more than fifty years, scientists
have described instances of 'rapid evolution' in specific
populations as their traits (phenotypes) change in response to
varying stressors. For example, Spanish clover has developed a
tolerance for copper from the mine tailings in which it grows,
and the horn size of Alberta bighorn sheep has decreased due to
trophy hunting. But until now it hasn't been possible to reach
any overarching conclusions about how different factors (such
as harvesting, climate change, invasive species, or pollution)
shape this rapid (now called 'contemporary') evolution.



FULL STORY ==========================================================================
Wild populations must continuously adapt to environmental changes or
risk extinction. For more than fifty years, scientists have described
instances of "rapid evolution" in specific populations as their traits (phenotypes) change in response to varying stressors. For example, Spanish clover has developed a tolerance for copper from the mine tailings in
which it grows, and the horn size of Alberta bighorn sheep has decreased
due to trophy hunting. But until now it hasn't been possible to reach any overarching conclusions about how different factors (such as harvesting, climate change, invasive species, or pollution) shape this rapid (now
called "contemporary") evolution.


========================================================================== Building on earlier work, a McGill University-led team has created a
massive new dataset of close to 7,000 examples of changing traits in
various populations around the world, from house sparrows and gray wolves
to freshwater snails and Canadian goldenrod. The dataset is 80% larger
than any that existed in the past and documents trait changes that are a mixture of evolution and immediate (plastic) responses to the environment.

Human disturbances affect evolution "We have come a long way from the
old view of evolution as a slow process to the point where we are now
realizing that everything is evolving all around us all the time," says
Andrew Hendry, a Professor of Biology at the Redpath Museum of McGill and
the co-senior author on the paper recently published inMolecular Ecology.

The researchers were especially interested in how various types of
human disturbance influence changes in traits. "We found a small but
real difference in rates of change between human disturbed and natural populations," explains Kiyoko Gotanda, the co-senior author, and an
Assistant Professor of Biological Sciences at Brock University where the
data is housed. "Moreover, the very highest rates of change are nearly
always those associated with intensive human disturbance" adds Hendry.

Pollution has a significant impact on evolution Analyses of the expanded dataset also confirms that harvesting by humans results in larger rates
of change than non-human disturbances, and that introduced populations
have increased rates of change. Interestingly, the researchers found
that pollution was responsible for the most rapid rate of phenotypic
change -- with zinc tolerance in tufted hair grass increasing by 80%
over 26 years, for example. They also suggest that it is now difficult
to judge what is a "natural habitat" since climate change is probably
affecting most populations.

"The critical next question is how this contemporary change matters for populations, communities, and ecosystems, as well nature's contribution
to people," adds first author Sarah Sanderson, a PhD candidate in Biology
at McGill. "We know, for instance, that salmon have been getting smaller
over the last century. This reduction in body size of such an important
fish has huge impacts -- birds, bears, and fish now have less to eat, Indigenous people have to catch more fish per meal, and the payoff is
lower for commercial fishers." "Similar effects must surely attend many
of the other trait changes observed in countless organisms across the
globe," adds Hendry.

========================================================================== Story Source: Materials provided by McGill_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Sarah Sanderson, Marc‐Olivier Beausoleil, Rose E. O'Dea,
Zachary T.

Wood, Cristian Correa, Victor Frankel, Lucas D. Gorne', Grant
E. Haines, Michael T. Kinnison, Krista B. Oke, Fanie Pelletier,
Felipe Pe'rez‐Jvostov, Winer D. Reyes‐Corral, Yanny
Ritchot, Freedom Sorbara, Kiyoko M. Gotanda, Andrew P. Hendry. The
pace of modern life, revisited. Molecular Ecology, 2021; DOI:
10.1111/mec.16299 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220119135037.htm

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