News: Dramatic reverse evolution among fish species.

Dramatic reverse evolution among fish species: study

http://www.ptinews.com/pti/ptisite.nsf/$all/E388352590F945C86525744E00490E5D

Washington, May 19 (PTI) Scientists have discovered a process of
"reverse evolution" among tiny fish species living in Lake Washington,
a finding that is being linked to a pollution-control effort in the
United States.
The study published in the latest online edition of Current Biology
showed that evolutionary process was taking place in relative
warp-speed reverse in the case of the threespine stickleback fish,
which live in Lake Washington, the largest of three major lakes in the
Seattle area.

Thanks to a USD 140 million cleanup effort in the mid-1960s -- at the
time considered the most costly pollution-control effort in the US --
today the lake's transparency has reached a depth of 10 feet.

Lacking the cover of darkness they once enjoyed, over the past 40
years about half of Lake Washington sticklebacks have evolved to
become fully armoured, with bony plates protecting their bodies from
head to tail.

The researchers at Fred Hutchinson Cancer Research Centre found that
while in the late 1960s, only 6 percent of sticklebacks were
completely plated, today 49 percent are fully plated and 35 percent
are partially plated, with about half of their bodies shielded in bony
armor.

"We propose that the most likely cause of this reverse evolution in
the sticklebacks is from the higher levels of trout predation after
the sudden increase in water transparency," said senior author
Catherine "Katie" Peichel.

Back when the lake was polluted, the transparency of its water was
low, it provided the sticklebacks with an opaque blanket of security
against predators such as cutthroat trout, said a report in the
ScienceDaily online.

--
Bob.

.

Relevant Pages

  • Re: Sad Fact
    ... transmitting rage. ... I've never driven over Trail Ridge Road. ... found a great B&B just a block from the lake, ... I thought we were house-bound this Summer because of the Washington DC ...
    (rec.sport.football.college)
  • Re: UK street names
    ... Eighth, Elm, View, Washington, Ninth, Lake and Hill. ...
    (alt.usage.english)
  • Re: Sad Fact
    ... I've never driven over Trail Ridge Road. ... found a great B&B just a block from the lake, ... I thought we were house-bound this Summer because of the Washington DC ... Many of the things you will see on your trip to Washington, ...
    (rec.sport.football.college)
  • Re: Sad Fact
    ... I've never driven over Trail Ridge Road. ... found a great B&B just a block from the lake, ... I thought we were house-bound this Summer because of the Washington DC ... Many of the things you will see on your trip to Washington, ...
    (rec.sport.football.college)