Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sexy sons thanks to mom

29.09.2011
It is not the superior genes of the father, but the mother’s resource investment in the eggs that makes Zebra Finch males particularly attractive. A Swiss-Australian research team lead by evolutionary ecologists at the University of Zurich has challenged the theory that females mate with superior males to obtain good genes for their offspring.

In Zebra Finches, as in most other bird species, both parents contribute to offspring rearing. The social partner of a female, however, is not always the biological father of the young. If the opportunity arises, females will choose to pair with partners other than their primary mate – with the interesting result that the offspring of different fathers have different qualities. And, as evolutionary ecologists from the University of Zurich and biologists from Macquarie University in Sydney have discovered, offspring sired by an extra-pair partner develop larger color ornaments and are more attractive to females than their social half-brothers.


A Zebra Finch male displaying his color ornaments.

Extra-pair males are not more attractive

Up to now, the quality differences between social and extra-pair offspring have generally been assumed to reflect the genetic superiority of the extra-pair male. Indeed, females are believed to engage in extra-pair copulation with genetically superior males to obtain better genes for their offspring. Now, Barbara Tschirren, professor for evolutionary ecology at the University of Zurich, and her team have challenged the idea of the exceptional male. In a study published in «Proceedings of the Royal Society» the researchers demonstrate that – despite the observed quality differences – the fathers of attractive sons are neither better looking nor genetically superior.

The first eggs receive preferential treatment

According to the study, attractive sons are not the result of exceptional genes; rather, their enhanced ornamentation is due to the mother’s investment in the eggs. Tschirren was able to demonstrate that maternal resource investment decreases steadily over the course of the laying sequence of a Zebra Finch, with eggs laid early in a clutch being larger and containing more nutrients and hormones. Favoring early eggs and the first hatchlings is a worthwhile investment for the mother as these offspring have a demonstrably higher chance of survival. «It appears that there is strong competition among males to fertilize these valuable eggs early in a female’s laying sequence», explains lead author Barbara Tschirren. «They try to exploit the female’s egg investment bias to ensure a head start for their own offspring.» She hypothesizes that sperm competition might decide the battle, with males with faster sperm being able to fertilize the most valuable eggs.

Literature:
Barbara Tschirren, Erik Postma, Alison N. Rutstein, Simon C. Griffith: When mothers make sons sexy: Maternal effects contribute to the increased sexual attractiveness of extra-pair offspring, in: Proceedings of the Royal Society B, 28 September 2011, DOI:10.1098/rspb.2011.1543
Contact:
Prof. Dr. Barbara Tschirren
University of Zurich
Institute of Evolutionary Biology and Environmental Studies
Phone: +41 44 635 47 77

Nathalie Huber | idw
Further information:
http://www.uzh.ch

Further reports about: Tschirren bird species color ornaments finch zebra zebra finch

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>