In mosquito, a small tale of climate change - Boston Globe

[Eugene]

Source: Boston Globe

THE 45TH PARALLEL | WARMING WHERE WE LIVE

In mosquito, a small tale of climate change

By Beth Daley, Globe Staff | April 29, 2007

Fourth in a series of occasional articles examining climate
change, its effects, and possible solutions.

UNORGANIZED TERRITORIES, Maine -- In a woodsy bog on the road
between Millinocket and Baxter State Park, a mosquito that can barely
fly is emerging as one of climate change's early winners.

The insect, which lives in the carnivorous purple pitcher plant, is
genetically adapting to a warming world. By entering hibernation more
than a week later than it did 30 years ago, the Wyeomyia smithii
mosquito is evolving to keep pace with the later arrival of New
England winters.

Along with Canadian red squirrels and European blackcap birds, the
mosquito -- a non biting variety found from Florida to Canada -- is one
of only five known species that scientists say have already evolved
because of global warming.

-snip-

Until now, the effects of climate warming had been most noticeable in
the Arctic, as glaciers melt. But dramatic changes are also being seen
in northern temperate zones such as New England, where the average
winter temperature has risen 4.4 degrees Fahrenheit over the last 30
years. Growing seasons have lengthened, winter is arriving later, and
the weather has become more erratic.

Scientists are worried that climate change, caused largely by the
release of heat-trapping gases from power plants and cars, will drive
evolution in unpredictable and unwelcome ways in these regions,
where millions of people live. Researchers are trying to determine in
more detail how species will adapt to a projected 3.2- to 7.2-degree
rise in the world's average annual temperature by the end of the
century. Their answers could help predict outbreaks of diseases
spread by insects and rodents, and how ecosystems will change as
species react at different rates to the warming.

-snip-

Read more: http://www.boston.com/news/local/articles/2007/04/29/in_mosquito_a_small_tale_of_climate_change

[OlderButWiser]

1. I'm not sure I'm following this:

"The insect, which lives in the carnivorous purple pitcher plant, is
genetically adapting to a warming world. By entering hibernation more
than a week later than it did 30 years ago, the Wyeomyia smithii
mosquito is evolving to keep pace with the later arrival of New
England winters."

Doesn't it only enter hibernation based on temperatures?

[Eugene]

2. According to the article...

hibernation is genetically programmed timing.

If the mosquito start hibernating too soon, the it wastes
resources and might not survive the winter. If it starts
too late, it will freeze to death. The mosquitoes that
survive pass on their hibernation traits to their offspring.

The point is that insects and rodents are adapting fast.

[mike_c]

3. yes and no....

It's not really "hibernation" in the sense that bears hibernate. Insects enter a state called diapause. It's more than just dormancy-- there is a whole suite of metabolic and life-history adaptations that are involved. Some of these are responses to external cues, but photoperiod is a more reliable seasonal cue than temperature. Others are hardwired to occur during specific portions of the life-cycle. These are the ones that I presume are evolving in response to warming temperatures.

[OlderButWiser]

5. is it evolving or

has it always been programmed to adapt to temperature changes? I'm thinking of the dandelion. It will grow tall flowers, but if you mow it, it will then grow short flowers as a way to produce seed. I don't think that the dandelion is evolving.

[mike_c]

6. that's a good question-- is the observed difference in behavior...

...the result of changing allele frequencies (evolution) or simply phenotypic plasticity? That would be easy enough to test-- just rear a few generations of mosquitoes under the old conditions and see whether they switch back easily or whether it takes several generations at least.

[sam sarrha]

4. the altitude which mosquitoes live that carry malaria is raising all the time, they prefer a specifi...

temperature.. temp is rising