Navigation Links
Battle of the sexes offers evolutionary insights
Date:5/3/2012

In a paper published May 3, in the journal Evolution, University of Cincinnati graduate student Karl Grieshop and Michal Polak, associate professor of biological sciences at UC, examine the role of genital spines in the reproductive success of a species of fruit fly. Their investigation identifies the specific type of advantage these spines bestow in the competition to reproduce.

"The leading hypothesis to explain the remarkable diversification of male genital traits is that such complexity evolves in response to sexual selection," Grieshop said. "Specifically, mechanisms of sexual selection operating during and after mating, such as sperm competition and cryptic female choice, have received the most support."

Grieshop and Polak have found compelling evidence that the spiny genitals of these male fruit flies provide the most benefit before the sexual act, rather than during mating or afterward. They achieved this understanding by using a precision laser surgery system to trim the claw-like spines of hundreds of male fruit flies and monitoring their success in a variety of mating situations.

Of the many species of fruit fly, they chose Drosophila ananassae because of the extraordinary length of these males' genital spines. Using the laser system, they removed the spines completely from some males, cut the spines in half on others, and merely blunted the spine tips on the final group.

Grieshop and Polak discovered that males with their spines completely removed were unable to copulate at all. Males with spines cut in half saw a profound reduction in sexual success. Those whose spines were merely blunted suffered a slight, non-significant reduction in copulation success, which was intensified to a statistically significant effect in sexually competitive environments. They likewise found the decrease in copulation success of partial-cut males was much stronger in competitive environments. And, it is in competitive environments where fruit flies most often mate.

"The mating system of these flies is best described as 'scramble competition,'" Grieshop said. "They swarm on rotting fruit. Some females are receptive. Others are not. The premium goes to males that can mate efficiently with many females before they are usurped by sexual rivals"

In such a chaotic environment females are known to exercise choice prior to mating according to the scent of pheromones, sounds of mating calls, or the visual cues of courtship dances, Grieshop said. But with regard to the surgical treatments of these genital spines, females apparently do not discriminate between competing male treatments.

"It appears that these spines promote male copulation success in this sort of environment," Grieshop said. "Identifying the precise function of a trait that varies across species, such as these spines, provides insight into the evolutionary pressures that caused them to evolve and also how new species may arise. Most adaptive functions of genitalia so far discovered only make a difference after mating has begun. For genitalia to make a difference before copulation is unusual. This puts genital traits on the same playing field as so-called 'secondary sexual traits,' like coloration or other adornments."

The research, he said, encourages the scientific community to consider male genital trait evolution as being similar to that of secondary sexual traits, which may facilitate the understanding of one of the greatest unknowns in evolutionary biology: why male genitalia are so incredibly variable across species.


'/>"/>

Contact: Greg Hand
greg.hand@uc.edu
513-556-1822
University of Cincinnati
Source:Eurekalert  

Related biology news :

1. Carp dominate crayfish in invasive species battleground
2. Bacteria battle against toxic fluoride
3. Savannas, forests in a battle of the biomes, Princeton researchers find
4. The remarkable history of medicines battle with infectious diseases
5. The battle of the morphogens: How to get ahead in the nervous system
6. Trudeau Institute announces new discovery in battle against infections
7. Battle won against Asian tiger mosquito
8. Trudeau Institute announces new discovery in battle against plague and bacterial pneumonias
9. Plant pathologist finding Kansas wheat fields a molecular battleground this season
10. Stevens biomedical engineering students fight hypothermia on the battlefield
11. Battle scars found on an ancient sea monster
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Battle of the sexes offers evolutionary insights
(Date:3/27/2021)... ... March 25, 2021 , ... Phlexglobal announced ... Planet Group, has selected Phlexglobal and its innovative regulatory SaaS software, PhlexSubmission, as ... a comprehensive review of five regulatory software companies, with the review team including ...
(Date:3/27/2021)... ... 25, 2021 , ... The 2021 Virtual Conference on Clinical Trial Supply-Europe ... More and more, clinical trial supply conferences are featuring speakers and forums that ... Asymmetrex’s founder and CEO, James L. Sherley, M.D., Ph.D., presented a talk ...
(Date:3/23/2021)... ... March 23, 2021 , ... G-CON Manufacturing (G-CON), the ... by Matica Biotechnology (Matica Bio), a contract development and manufacturing organization (CDMO) specializing ... the cleanroom build out for its new GMP production facility in College Station, ...
Breaking Biology News(10 mins):
(Date:3/27/2021)... ... March 24, 2021 , ... ... Life Sciences and Healthcare firms of all sizes, adds depth to its team ... specialist. Pardillo, who earned his doctorate in computational chemistry from Florida International University ...
(Date:3/27/2021)... ... March 24, 2021 , ... ABI Wellness, ... and reporting approach designed under CEO Mark Watson, today announced a webinar dedicated ... featuring guest speakers Dr. Cameron Clark, Neuropsychologist and Founder of Sharp Thinking, and ...
(Date:3/27/2021)... ... ... The Xtalks editorial team is pleased to announce the launch of the ... joined by editorial team members Ayesha Rashid, Sydney Perelmutter and Mira Nabulsi to discuss ... including insights from industry experts. , The Xtalks Life Science podcast will feature ...
(Date:3/23/2021)... Conn. (PRWEB) , ... March 23, 2021 , ... ... develops solutions for characterizing microbiome populations down to the strain level, recently unveiled ... applications. , Not all microbes are created equal: some are easy to ...
Breaking Biology Technology: