Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

European dung-fly females all aflutter for large males

13.04.2012
European dung fly females prefer large males, making them the driving selective force behind the rare phenomenon in insects of large males and small females.
This is what evolutionary ecologists from the University of Zurich discovered when they compared North American and European dung flies, which not only differ in sexual size dimorphism (SSD), but also in their mating behavior.

European and North American black scavenger flies – also called dung flies as their larvae develop in the feces of vertebrates and thus break them down – belong to the same species. Nevertheless, they strongly differ in mating behavior and SSD. North American dung fly females are larger than males, the usual dimorphism in insects. European dung flies, however, are more unusual with males being considerably larger than females.

European and North American dung flies differ in their mating frequency. (picture: UZH)

In evolutionary biology, sexual selection for large males can be explained if they can reproduce more successfully than smaller ones, either because females prefer larger males or because the latter prevail more often in the competition for mates with other males. Evolutionary ecologists from the University of Zurich showed that female preference for large males is far greater in European fly populations than in their North American counterparts, which explains the different SSD.

Different mating behavior
North American dung fly males woo the females with a courtship dance. Project leader Wolf Blanckenhorn does not rule out the possibility that North American males also deploy pheromone-like scents during courtship. This courtship dance is entirely absent in the European flies: males mount the females relatively randomly, cling onto them with varying degrees of success and try to mate with them, even though they are often shaken off again by the females before copulation.
European dung flies copulate more often
European and North American dung flies also differ in their mating frequency. During their roughly 40-day adult life, European dung flies mate often, their North American counterparts only once or twice. “Frequent copulation requires more sperm from the males and therefore larger testes,” explains Blanckenhorn. This could well be a contributory factor in the European females’ greater preference for large males. However, the connection between the continental differences in SSD and mating behavior is still unclear: “What is an evolutionary cause and what an effect can only – if at all – be reconstructed indirectly today,” concludes Blanckenhorn.
Literature:
Nalini Puniamoorthy, Martin A. Schäfer and Wolf U. Blanckenhorn. Sexual Selection Account for the Geographic Reversal of Sexual Size Dimorphism in the Dung Fly Sepsis Punctum (Diptera: Sepsidae). Journal Evolution. March 16, 2012. doi:10.1111/j.1558-5646.2012.01599.x
Contact:
Prof. Dr. Wolf Blanckenhorn
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Tel.: +41 44 635 47 55
Email: wolf.blanckenhorn@ieu.uzh.ch

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

More articles from Life Sciences:

nachricht Molecular motors run in unison in a metal-organic framework
20.03.2019 | University of Groningen

nachricht Active substance from plant slows down aggressive eye cancer
20.03.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Molecular motors run in unison in a metal-organic framework

20.03.2019 | Life Sciences

Active substance from plant slows down aggressive eye cancer

20.03.2019 | Life Sciences

Novel sensor system improves reliability of high-temperature humidity measurements

20.03.2019 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>