Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Picking the best parent for your chicks

19.04.2006
The local boy with the most bling is a good choice in the spring, but as summer progresses a girl bird’s best bet is a stranger.

Who’s chosen by whom in the mating game is determined by seasonal changes in the genetic diversity of available mates, according to new research based on a 10-year study of wild finches.


A pair of house finches showing the bright breeding plumage of the male. Photo credit: Alex Badyaev.


Three male house finches, all with slightly different red mating plumage, strut their stuff in front of a female house finch. Photo credit: Alex Badyaev.

The finding helps explain a long-standing evolutionary biology paradox.

Previous research has shown that female birds often go for the flashier guys. Many biologists argue that sexual selection -- competition for mates -- is the driving force behind the evolution of such elaborate and seemingly useless getups as a male peacock’s tail.

"For such elaborate traits to evolve, you have to have mating patterns where everyone wants the same thing," said lead researcher Kevin P. Oh of The University of Arizona in Tucson.

But if everyone mates with the same perfect-looking individual, ultimately that would result in inbreeding, he said.

Particularly healthy kids are produced when the parents are genetically different -- what biologists call complementarity. However, choosing one’s genetic better half would generate more diversity in looks, rather than pushing the population toward a uniform dandified appearance.

Alexander V. Badyaev, principal investigator for the UA study, said, "Even though preference for genetically complementary mates is widely documented, it’TMs always puzzled people that individual differences in mate preference do not prevent the evolution of elaborate ornaments."

It all comes down to who’s available when a bird is ready to breed, said Oh and Badyaev. Early on, the available mates aren’t genetically diverse but some males are very flashy. Later in the season, females who arrive from out of town may not find a flashy male, but can end up with a stranger with genes different from her own.

The whole system is driven by the fact that female birds generally leave home to breed, while the males stay put and breed near their birthplace.

The researchers found that having two seasonal rounds of mate choice, where the second round lessens the inbreeding that would result from the first, not only provides a new explanation of how birds choose mates, but also may apply to other members of the animal kingdom.

Oh, a doctoral student in UA’s department of ecology and evolutionary biology, and Badyaev, an assistant professor in the same department, will publish their research paper, "Adaptive genetic complementarity in mate choice coexists with selection for elaborate sexual traits" in an upcoming issue of Proceedings of the Royal Society B. The National Science Foundation funded the research.

Since 1995, Badyaev has been intensively studying a population of house finches (Carpodacus mexicanus) in one site near Missoula, Mont. He now knows intimate details about the lives of approximately 12,000 finches.

During the breeding and nesting season, Badyaev and his team capture birds every day to band and photograph them, take DNA samples and body measurements and track their hormonal status throughout the season.

The photos and biochemical analysis of the males’ ornamental feathers, which range from dull yellow to deep purple, record how bright the male is in relation to other males.

To determine each bird’s genetic make-up, the researchers use a technique called microsatellite DNA genotyping. They also track birds’TM hormonal profiles and ovulation cycles to determine each female’s fertilization window.

The team also locates all the nests, keeps track of activity in the nest and takes DNA samples from the chicks. Badyaev said, "We have 10 sequential generations of wild birds completely genotyped -- it’s never been done before."

The researchers know who was available for mating at any particular point in time, who actually mated with whom, who their kids are and whether their kids survived. The team even knows who participated in "extramarital" trysts that resulted in offspring.

Badyaev said, "We found that each female has about a 10-day period during which mating will result in fertilization." He added, "We thus can see, for each female, whether the male she chose was indeed the most colorful or the most genetically diverse of all males available during her fertility window."

Early in the season, females picked the reddest guy around, not the one most genetically different from her, the researchers found.

As the flashiest males got snatched up, females arriving later had different choices. Those out-of-towners, genetically different from the locals, ended up with mates that were genetically different from themselves.

And for birds who snuck out for some sex on the side, the researchers found those birds likely chose an out-of-town partner who was more genetically different than their regular mate.

It’s a good thing opposites attract, the researchers found -- baby birds with the best survival rates had parents who were dissimilar genetically.

Oh said the team’s research shows that basic ecological processes by which young females disperse and males stay home creates seasonal cycles of variability in sexual ornamentation and genetic diversity. That overall pattern makes it easy for birds to find their genetic better half and simultaneously enables the evolution of elaborate sexual displays.

Oh and Badyaev are now doing a similarly intensive study of house finches on the UA campus to see if their findings hold up for birds living in different environment.

Mari N. Jensen | EurekAlert!
Further information:
http://www.arizona.edu

More articles from Life Sciences:

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>