Featured Research

from universities, journals, and other organizations

Genetic 'battle of the sexes' more important to evolution than thought, beetle study suggests

Date:
November 7, 2010
Source:
University of Exeter
Summary:
A new study of beetles shows a genetic 'battle of the sexes' could be much harder to resolve and even more important to evolution than previously thought. This battle, observed across many species and known as intralocus sexual conflict, happens when the genes for a trait which is good for the breeding success of one sex are bad for the other -- sparking an 'evolutionary tug-o-war' between the sexes.

These are two male broad-horned flour beetles locked in battle.
Credit: Dr. Kensuke Okada

A new study of beetles shows a genetic 'battle of the sexes' could be much harder to resolve and even more important to evolution than previously thought.

This battle, observed across many species and known as intralocus sexual conflict, happens when the genes for a trait which is good for the breeding success of one sex are bad for the other -- sparking an 'evolutionary tug-o-war' between the sexes.

It has previously been thought these issues were only resolved when the trait in question evolves to become sex-specific in its development -- meaning the trait only develops in the gender it benefits and stops affecting the other. An example of this is male peacocks' tails, used for mating displays, which are not present in females.

However, a new study by the universities of Exeter (UK), Okayama and Kyushu (both Japan) published Nov. 4 in Current Biology shows this doesn't always bring an end to conflict -- as even when the trait becomes sex-specific, knock-on effects can still disadvantage the other sex.

Professor Dave Hosken, from the Centre for Ecology & Conservation (Cornwall) at the University of Exeter, said: "This kind of genetic tussle is everywhere in biology. For example, in humans, male hips are optimised for physical activity, whereas female hips also need to allow child bearing. That's the sort of evolutionary conflict we're talking about, and these conflicts were previously thought to be resolved by sex-specific trait development.

"What we're seeing in this study is that this isn't always the end of the sexual conflict. This means it's no longer clear how or when, if ever, these conflicts get fully resolved and this means it could be more important to the evolutionary process than has generally been thought."

In this study, the researchers looked at broad-horned flour beetles, where males have massively enlarged mandibles used to fight other males for mating supremacy. The enlarged mandibles aren't present in the females at all -- meaning this is a sex-specific trait.

By selectively breeding the beetles for larger or smaller mandible size, the researchers were able to show that the bigger the mandibles were -- the more successful the males were in breeding. There was a corresponding counter-effect on females, however, as females from larger mandibled populations were less successful.

Professor Takahisa Miyatake, from the Graduate School of Environmental Science at Okayama University, said: "We looked at all the possible reasons for this and found that while the females did not develop the larger mandibles, they did inherit many of the other characteristics that made the enlarged mandibles possible in males. This included a reduced abdomen size, which could affect the number of eggs a female can carry -- giving a possible explanation for the disadvantage.

"So here we see a sex-specific trait which is still having a negative effect on the sex which doesn't show it. This means that even though it looks like this genetic conflict is over, it's still ongoing and there's no easy way to end it."

Kensuke Okada, also from Okayama University, said: "The view that sex-limited trait development resolves this kind of genetic battle of the sexes is based on the assumption that traits are genetically independent of each other, which is frequently not true.

"What we're seeing here is that genetic architecture can provide a general barrier to this kind of conflict resolution."


Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tomohiro Harano, Kensuke Okada, Satoshi Nakayama, Takahisa Miyatake, and David J. Hosken. Intralocus Sexual Conflict Unresolved by Sex-Limited Trait Expression. Current Biology, 2010; DOI: 10.1016/j.cub.2010.10.023

Cite This Page:

University of Exeter. "Genetic 'battle of the sexes' more important to evolution than thought, beetle study suggests." ScienceDaily. ScienceDaily, 7 November 2010. <www.sciencedaily.com/releases/2010/11/101104154219.htm>.
University of Exeter. (2010, November 7). Genetic 'battle of the sexes' more important to evolution than thought, beetle study suggests. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2010/11/101104154219.htm
University of Exeter. "Genetic 'battle of the sexes' more important to evolution than thought, beetle study suggests." ScienceDaily. www.sciencedaily.com/releases/2010/11/101104154219.htm (accessed September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins