Researchers test whether Red Queen hypothesis makes species resilient

May 20, 2014 by Gary Galluzzo
In this illustration, Alice meets the Red Queen. Credit: ©John Tenniel [Public domain], via Wikimedia Commons

In Lewis Carroll's 1871 classic novel Through the Looking Glass, the Red Queen tells Alice: "Now, here, you see, it takes all the running you can do, to keep in the same place."

Over the years, evolutionary biologists have used the Red Queen's statement to refer to the "Red Queen" hypothesis, which describes how living organisms, including humans, manage to survive in a changing environment by adapting through . According to a University of Iowa researcher, the hypothesis is supported.

In a paper published in the journal Biology Letters, lead author Deanna Soper, postdoctoral researcher in the UI Department of Biology and currently visiting assistant professor at Beloit College, Beloit, Wisconsin, and her colleagues write about testing a version of the Red Queen hypothesis.

In particular, they addressed whether a particular prediction of the hypothesis was met—that exposure to parasites increases multiple mating in New Zealand freshwater snails (Potamopyrgus antipodarum).

What they found was that a challenge to the health of the snails caused the snails to respond by increasing their rate of mating and their number of mates.

Researchers test whether Red Queen hypothesis makes species resilient
Biologists used New Zealand freshwater snails in their research. Credit: Bart Zijlstra

"Under the Red Queen hypothesis, sexual reproduction gives an advantage over because sexually reproducing organisms 'shuffle' their genes during sex cell formation and fusion of sex cells from two individuals," says Soper. "This means that the resulting offspring of sexually reproducing individuals may have an increased likelihood of escaping infection due to the production of unusual genetic backgrounds.

"Here, we test the prediction that exposure to parasites would increase mating behavior and number of sexual partners. We found that indeed parasites cause an increase in mating activity and promiscuity when exposed to parasites," she says.

What Soper and her colleagues did was to expose the fresh-water snails to the eggs of a parasite that have the effect of sterilizing the snails. Interestingly, they found that such exposure caused both male and female snails to increase their sexual behavior.

At issue was the mystery of why sexual reproduction is so common among organisms and why it evolved in the first place—central questions in the field of evolutionary biology. After all, asexual females—which exist among freshwater snails and some other organisms—should be able to produce twice as many daughters as sexual females who produce both male and female offspring. Asexual reproduction would appear to have an advantage because only females produce offspring and females thus limit the rate at which populations grow.

In her summary, Soper speculates that multiple mating could increase genetic diversity among offspring, thereby making them more resistant to the risk of infection from parasites found in nature. She suggests that future studies investigate how other environmental factors influence behavior.

Explore further: Study brings greater clarity to sex roles

More information: The paper, whose title is "Exposure to parasites increases promiscuity in a freshwater snail," can be found here: rsbl.royalsocietypublishing.or… t/10/4/20131091.full

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someone11235813
not rated yet May 20, 2014
Does this imply that increased promiscuity amongst H. sapiens, is the best way to combat STD's in the long term? Shall we all sacrifice ourselves to pernicious diseases in order to breed immunity into the 22nd century.
animah
not rated yet May 20, 2014
Not really - promiscuity does not equal more babies in the age of birth control.

But it does show that racism and other "racial purity" bullshit decreases genetic diversity and therefore long-term resilience.
gwrede
not rated yet May 20, 2014
Today, our life is full of stress with a hectic lifestyle, too much work, and increasingly too little money. Could it be that this kind of stressors work the same as having parasites? Then promiscuity would follow. Contrast that with pastoral settings (Little House on the Prairie), where life is secure, stable and peaceful, and where you see people married to high school sweethearts and lasting marriages.

Just a thought.
JVK
1 / 5 (1) May 20, 2014
"The most likely explanation for the fitness advantage conferred by genomic and metabolic "streamlining" in both natural and experimental populations is that it reduces the amount of carbon and other limiting nutrients required to produce a new cell (12, 15, 16)." -- http://mbio.asm.o...abstract

That fact pits the Black Queen hypothesis against the Red Queen hypothesis.
http://phys.org/n...sis.html

However, no experimental evidence of biologically based cause and effect supports the Red Queen hypothesis, which is based on the pseudoscientific nonsense of population genetics. For comparison, the Black Queen hypothesis integrates all that is currently known from physics, chemistry, and conserved molecular mechanisms about nutrient-dependent pheromone-controlled reproduction in species from microbes to man. For examples, see:

http://www.ncbi.n...24693353