Featured Research

from universities, journals, and other organizations

Female promiscuity can rescue populations from harmful effects of inbreeding, beetle study finds

Date:
September 30, 2011
Source:
University of East Anglia
Summary:
Females in inbred populations become more promiscuous in order to screen out sperm from genetically incompatible males, according to new study by the University of East Anglia (UEA).

Females in inbred populations become more promiscuous in order to screen out sperm from genetically incompatible males, according to new beetle study by the University of East Anglia (UEA).

Published in the journal Science, the findings help answer the puzzling evolutionary question of why females in most species mate with multiple males -- even though a single male can provide full fertility and promiscuity can carry fatal risks for the female.

Using the red flour beetle as a model species, the researchers investigated the reproductive benefits of female promiscuity -- or 'polyandry'. Polyandry, where a female's eggs are fertilized by multiple fathers, is the norm in most species, from chimpanzees to chickens, salmon to sea urchins. While biologists have recorded significant costs to females of this mating pattern, even death, these new findings show there can also be genetic benefits.

The UEA team found that the reproductive success of females in populations that were not inbred was identical, whether mating with one or five males. In inbred populations, females mating with just one male showed a 50 per cent reduction in the number of surviving offspring they could produce. However, inbred females who mated with five males managed to rescue their reproductive success back up to the levels of the non-inbred populations. The researchers checked to see if this could be explained by male infertility, but inbred males are just as fertile as non-inbred males. The effect was therefore due to genetic incompatibility between males and females, which is prevalent when a population becomes inbred. Importantly, the results show that females possess mechanisms that allow them to filter in the genetically most compatible sperm to produce more viable offspring.

Having made this discovery, the researchers then went on to create deliberate genetic bottlenecks in populations of flour beetles and demonstrated for the first time that after as few as 15 generations, females began to change their mating patterns and behave far more promiscuously. Females from the previously bottlenecked populations mated with new males faster, more frequently, and for longer.

"By generating inbred populations, we were able to create real risks of high genetic incompatibility between reproducing males and females, and expose the mechanisms that females possess to promote fertilization by the most compatible males and their sperm," said lead author Prof Matthew Gage of UEA's School of Biological Sciences.

"These exciting results show how this common but paradoxical mating pattern can evolve if females use it to avoid reproducing with genetically incompatible males. Exactly how females filter the most compatible sperm is not yet understood. They might simply mate more frequently, and allow the 'best sperm to win', which would work if winning sperm are from males who have themselves avoided inbreeding depression. Or they might choose to mate most with the less related males, perhaps using olfactory cues, thereby concentrating their sperm stores from those males. We think that the process occurs most likely at the gamete level, because females mate with most of the males they are exposed to and only store for fertilization a tiny proportion of the sperm they are actually inseminated with. We know that sperm:egg recognition systems exist in other systems to avoid fertilization by unrelated species, and here it could run parallel where the system avoids fertilization by males that are too closely related."

The results could be of interest to those involved in breeding programmes, where providing females or their eggs with a choice might allow more compatible genes to be inherited.

"There's a telling example here from salmon restocking programs: should you maintain genetic diversity in the population by forcing each female to be fertilized by one different male, as is currently favoured, or should you let the natural mating pattern apply and give the eggs a choice of a mix of sperm? We're now testing this applied question directly with a project in Norway," added Prof Gage.

The five-year experimental evolution study was funded by the Natural Environment Research Council (NERC) and the University of East Anglia.


Story Source:

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


Journal Reference:

  1. L. Michalczyk, A. L. Millard, O. Y. Martin, A. J. Lumley, B. C. Emerson, T. Chapman, M. J. G. Gage. Inbreeding Promotes Female Promiscuity. Science, 2011; 333 (6050): 1739 DOI: 10.1126/science.1207314

Cite This Page:

University of East Anglia. "Female promiscuity can rescue populations from harmful effects of inbreeding, beetle study finds." ScienceDaily. ScienceDaily, 30 September 2011. <www.sciencedaily.com/releases/2011/09/110922141856.htm>.
University of East Anglia. (2011, September 30). Female promiscuity can rescue populations from harmful effects of inbreeding, beetle study finds. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2011/09/110922141856.htm
University of East Anglia. "Female promiscuity can rescue populations from harmful effects of inbreeding, beetle study finds." ScienceDaily. www.sciencedaily.com/releases/2011/09/110922141856.htm (accessed September 18, 2014).

Share This



More Plants & Animals News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) 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