Navigation Links
Females can place limits on evolution of attractive features in males, research shows
Date:8/4/2011

AUDIO: Male tngara frogs producing their distinctive "whine " and "chuck " calls to attract females.

Click here for more information.

AUSTIN, TexasFemale cognitive ability can limit how melodious or handsome males become over evolutionary time, biologists from The University of Texas at Austin, Louisiana State University Health Sciences Center and the Smithsonian Tropical Research Institute have observed.

Males across the animal world have evolved elaborate traits to attract females, from huge peacock tails to complex bird songs and frog calls. But what keeps them from getting more colorful feathers, longer tails, or more melodious songs? Predators, for one. Increased elaboration can draw predators in, placing an enormous cost to males with these sexy traits.

In a new paper appearing this week in Science, a group of biologists have shown that females themselves can also limit the evolution of increased elaboration.

Studying neotropical tngara frogs, they found that females lose their ability to detect differences in male mating calls as the calls become more elaborate.

"We have shown that the female tngara frog brains have evolved to process some kinds of information and not others," says Mike Ryan, professor of integrative biology at The University of Texas at Austin, "and that this limits the evolution of those signals."

Imagine looking at a group of five oranges next to a group of six. At a glance, you would quickly notice that one group has one more orange than the other. Now, imagine looking at a pile of 100 oranges next to a pile of 101. It would be nearly impossible for you to notice the difference in size (one orange) between those two piles at a glance. This is known as Weber's Law, which states that stimuli are compared based on proportional differences rather than absolute differences (one orange in the case above).

In tngara frogs, males gather en masse to attract female frogs with a call that is made up of a longer "whine" followed by one or more short "chucks."

Through a series of experiments conducted in Panama, Ryan and his collaborators found that females prefer male calls with the most chucks, but their preference was based on the ratio of the number of chucks. As males elaborate their call by adding more chucks, their relative increase in attractiveness decreases due to a perceptual constraint on the part of females.

Male tngara frog calls also attract a predator: the frog eating fringe-lipped bat. To confirm that male song elaboration wasn't limited by these predators, the researchers also studied how the bats respond to additional "chucks" in the male call.

They discovered that hunting bats choose their prey based on chuck number ratio, just as the female frogs do. So, as males elaborate their call by adding chucks, the relative increase in predation risk decreases with each additional chuck.

"What this tells us is that predation risk is unlikely to limit male call evolution," says Karin Akre, lecturer at The University of Texas at Austin. "Instead, it is the females' cognition that limits the evolution of increasing chuck number."


'/>"/>

Contact: Karin Akre
kakre@mail.utexas.edu
512-475-6164
University of Texas at Austin
Source:Eurekalert  

Related biology news :

1. Avian Axe effect attracts attention of females and males
2. Competition between females leads to infanticide in some primates
3. In fireflies, flightless females lose out on gifts from males
4. Differences in brain development between males and females may hold clues to mental health disorders
5. Male antelopes trick females into extra sex opportunities
6. Male antelopes deceive females to increase their chances of mating
7. Females shut down male-male sperm competition in leafcutter ants
8. Pesticide atrazine can turn male frogs into females
9. Exposure to young triggers new neuron creation in females exhibiting maternal behavior
10. Pesky fruit flies learn from experienced females: Study
11. Caffeine appears to be beneficial in males -- but not females -- with Lou Gehrigs disease
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Females can place limits on evolution of attractive features in males, research shows
(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
(Date:4/15/2016)... , April 15, 2016  A new partnership ... more accurate underwriting decisions in a fraction of ... competitively priced and high-value life insurance policies to ... With Force Diagnostics, rapid testing (A1C, ... data readings (blood pressure, weight, pulse, BMI, and ...
(Date:4/14/2016)... 14, 2016 BioCatch ™, ... today announced the appointment of Eyal Goldwerger ... Goldwerger,s leadership appointment comes at a time ... the deployment of its platform at several of the ... which discerns unique cognitive and physiological factors, is a ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report ... detail how a patient who developed lymphedema after being treated for breast cancer benefitted ... change the paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
(Date:6/23/2016)... , June 23, 2016 ... Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... , the peer-reviewed journal from touchONCOLOGY, Andrew ... escalating cost of cancer care is placing an ... result of expensive biologic therapies. With the patents ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... quality, regulatory and technical consulting, provides a free webinar on Performing ... July 13, 2016 at 12pm CT at no charge. , Incomplete investigations are ...
(Date:6/23/2016)... ReportsnReports.com adds 2016 global ... pharmaceuticals section with historic and forecast data along ... Complete report on the Cell Culture ... companies and supported with 261 tables and figures ... The Global Cell Culture Media Industry ...
Breaking Biology Technology: