Evolutionary straitjacket means flies can’t take the heat
Many species of fruit fly lack the ability to adapt effectively to predicted increases in global temperatures and may face extinction in the near future, according to new research.
In a study published today in Proceedings of the National Academy of Sciences, researchers from Monash University, The University of Melbourne and Danish collaborators showed that many species of fruit fly appear to be constrained within an evolutionary straitjacket and can’t readily adapt to climate change-related temperature increases.
Dr Vanessa Kellermann from Monash University’s School of Biological Sciences said current projections predict a 3ºC increase in mean annual temperature in the next century and even greater increases in extremes.
“Given our findings, these expected increases pose a major threat to biodiversity in the near future. Particularly as Drosophila or fruit fly findings are often more broadly applicable,” Dr Kellermann said.
By examining nearly 100 species of fruit fly from around the world, the researchers showed that species had evolved to the temperature extremes and humidity of their environments. However, they had very little flexibility in being able to change their levels of heat resistance and seem unable to adapt to increased temperatures in the future.
High heat resistance is a feature of only some branches of the phylogeny – the tree that shows how species are related through evolution – of Drosophila. Other branches had very limited ability to change their levels of heat resistance; even when flies native to cooler areas grew up in a warm environment, their heat tolerance was not significantly altered.
“The problem is that only a handful of species have adapted to hot environments while most species have not and it seems very difficult to switch once you are stuck on a phylogenetic branch,” Dr Kellermann said.
The researchers looked at species’ prospects for dealing with projected temperature increases in the near future.
“If a species can only withstand temperatures of 36ºC and the maximum temperature of the environment is already 36ºC, an increase of even 1ºC would already put this species over the edge towards extinction,” Dr Kellermann said.
Using this method, the researchers identified at-risk species and found that most tropical and mid-latitude species fell into this category.
“Without rapid adaptation, which now seems very unlikely, a lot of species may fall over under even a mild increase in temperature,” Dr Kellermann said.
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I’m sure the people who have battled the Mediterranean Fruit Fly will be happy to hear this. It seems though this is just old recycled news used to paint GW in a scary light, here’s a paper from 1986:
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Developmental temperature and life span in Drosophila melanogaster. I. Constant developmental temperature: evidence for physiological adaptation in a wide temperature range.
Abstract
The concept of an inverse relationship between life span of adult Drosophila and their developmental temperature is probably the result of an unwarranted generalization. Rather, in a wild-type laboratory strain the present study revealed a plateau phase in this relationship between 16 and 29 degrees C in which life span of both male and female flies was roughly independent of developmental temperature. Below and above this range, life span dropped drastically, development being impossible below 12 and above 32.5 degrees C. Simultaneous study of growth characteristics showed that the plateau phase corresponded to a ‘physiological’ range of developmental temperature, development being apparently disturbed outside that range. Within that physiological range, the growth rate of the flies varied varied 2-fold, while life span remained constant corroborating our previous conclusion that growth rate per se does not determine life span.
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I find it humorous that Nature so poorly equipped flies over the billions of years of existence that they’ll just “fall over” once the temperature gets to 37C. So much for evolution and survival of the fittest. Contrast this to claims that GW will cause mosquitoes and others pests to flourish.
I wonder where David Suzuki stands on this news?
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How about MOSQUITOES. Any hope in genocide of them?
Think of it as evolution in action.
If global warming would kill all mosquitoes, ticks, fleas, yellow jackets and hornets, I’d go buy 2 Ford Excursions today….
Is Fruit Fly Doctor David Suzuki involved in this?
Yea, because fruit grows so much better in the cold.
We are discussing the extinction of fruit flies. Can someone explain why this would be a bad thing?
Sure, I believe this. Remember the 1970s movie Savage Bees – where they lure the marauding killer bees into the Superdome, then drop the temp with the Superdome’s exceptional A/C?
Those bees were dropping left and right.
“However, they had very little flexibility in being able to change their levels of heat resistance and seem unable to adapt to increased temperatures in the future.”
And what of evolution?
“The researchers looked at species’ prospects for dealing with projected temperature increases in the near future.”
Ah, the near future, I see.
“”This is actually decoding the key DNA in the evolution of aging, development and fertility,” said ecology & evolutionary biology professor Michael Rose, whose laboratory began breeding the “super flies” used in the current study in 1991 — or 600 generations ago. He joked that they “live fast and die young. Lead author and doctoral student Molly Burke compared the super flies to a control group on a genome-wide basis, the first time such a study of a sexually reproducing species has been done. The work married DNA “soup” gathered from the adapted flies with cheap, efficient technology that uses cutting-edge informatics tools to analyze the DNA of entire organisms. Burke found evidence of evolution in more than 500 genes that could be linked to a variety of traits, including size, sexual maturation and life span, indicating a gradual, widespread network of selective adaptation.”
http://www.sciencedaily.com/releases/2010/09/100916162537.htm
How many generations, I wonder, does the ‘near future’ equate to?
It’s a shame they can’t fly – then they could migrate to a cooler climate.
Just a minute …..
Oh no! Global warming killing fruit flies?
Dr. Suzuki will be so upset…
From my unfortunate experience, the hotter it gets, the more flies you get and it is much harder to catch them.
Again, it seems these people never left the lab to check how things are in the real world.
By the way, I am talking VERY high temps – above the 40C…
So fruit flies won’t adapt?
How it works: As temperatures rise, some percentage of fruit flies will exhibit greater tolerance for the higher temps, thus they will be the successful reproducers while the less adaptable flies will die off. The new generation will exhibit greater tolerance for higher temps, and so will their offspring.
Funny how that works.
Poor old Economos and Lints seem to have produced a more comprehensive paper in that they explore lower temperature effects as well. Shame for them that they did it before all the extra cash became available for any paper that mentions “temperature.”
Paul – I wish, mosquitoes have been found at nearly every temperature with standing non frozen water.
Adaptable little buggers…
There was a scientist (whose name I forget) on BBC Radio 4 recently who described his experiments to measure the environmental heat received by various insects using such methods as painting snails with the dye used in jeans that fades with heat. For fruit flies the colour of their eyes was used to measure the heat of the environment. He found that within the limits of a single field the variation experienced between different insects was between 20C to 30C centigrade.
I think that covers the maximum global warming range ever promised by the alarmists so those pesky flies will still be with us.
Dead Fruit flys are the best kind of fruit fly. They managed to get in my apartment and i could never get rid of them even with targeted extermination campaigns.
It’s a real conundrum. If we experience global warming, several species of fruit flies may go extinct. But if we don’t, several species of climate scientists may go extinct. Is there no way we can choose both? /sarc
Another BS study.
Fruitflies are remarkably adaptable across a broad range of climates.
This is like the faux study claiming to show how pythons were going to move to Kansas, or the one pretending that AGW would cause more kidney stones.
“By examining nearly 100 species of fruit fly from around the world, the researchers showed that species had evolved to the temperature extremes and humidity of their environments.”
And now they’ve lost that adaptability, doubtless due to the actions of evil humanity. (using them as laboratory specimens, perhaps?) Silly Melanogaster, inhabiting a planet with such creatures on it. They deserve to die!
Seriously, did they try breeding one of those ‘high-temperature” species, increasing the temperature by, say, 0.3° over 10 years, to try to duplicate the wild “predictions” of those “current projections”? I doubt the little blighters would have noticed it over all those generations.
So one atypical hot daytime peak can wipe them all out. I think not. If I were a fruit fly I’d be born when the temperature was slightly cooler, slightly earlier in the year than in the good old non-catastrophic days. But then I’m not a fruit fly.
The Warm List
We could do with fewer of these pests:
http://en.wikipedia.org/wiki/Olive_fruit_fly
“…in this relationship between 16 and 29 degrees C in which life span of both male and female flies was roughly independent of developmental temperature. Below and above this range, life span dropped drastically, development being impossible below 12 and above 32.5 degrees C.”
May I point out that total ‘global warming’ over the past 150 years has amounted to only about 0.8ºC? How will that exterminate fruit flies??
This is just another item we can add to the list:
Fruit flies already have the problem solved – just move in to climate controlled human habitats.
Time flies like an arrow. Fruit flies like a banana.