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Latest Sperm competition Stories

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2010-06-16 14:43:09

Inbred male sperm have been found to fertilize fewer eggs when in competition with non-inbred males according to a new study by the University of East Anglia. Research into the breeding habits of the red flour beetle, published June 15 in Proceedings of the Royal Society B, shows that the reduced fitness of inbred beetles, known as 'inbreeding depression', reveals itself in competitive scenarios. Inbreeding is a potentially important problem in declining species across the world, and...

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2010-04-05 07:49:32

Mothers win the genetic tug of war by producing more sons with larger fathers and more daughters with smaller fathers "Be faithful in small things because it is in them that your strength lies." Mother Teresa's words echo throughout the world. They ring particularly true in the biological kingdom among brown anole lizards, as evidenced in research detailed in the April 2 edition of the journal Science. Dartmouth researchers Ryan Calsbeek and Bob Cox study male and female brown anole lizards...

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2010-03-19 08:22:45

Previously unobservable events occurring between insemination and fertilization are the subject of a groundbreaking new article in Science magazine (March 18) by Mollie Manier, John Belote and Scott Pitnick, professors of biology in Syracuse University's College of Arts and Sciences. By genetically altering fruit flies so that the heads of their sperm were fluorescent green or red, Belote and his colleagues were able to observe in striking detail what happens to live sperm inside the female....

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2010-03-19 08:18:22

Leafcutter ant queens can live for twenty years, fertilizing millions of eggs with sperm stored after a single day of sexual activity. Danish researchers who have studied ants at the Smithsonian Tropical Research Institute in Panama since 1992 discovered that in both ant and bee species in which queens have multiple mates, a male's seminal fluid favors the survival of its own sperm over the other males' sperm. However, once sperm has been stored, leafcutter ant queens neutralize male-male...

2010-01-20 15:13:33

Spermatozoa from the same individual cluster together, improving motility in the race to the egg Some mouse sperm can discriminate between its brethren and competing sperm from other males, clustering with its closest relatives to swim faster in the race to the egg. But this sort of cooperation appears to be present only in certain promiscuous species, where it affords an individual's sperm a competitive advantage over that of other males. The work is described this week in the journal Nature...

2009-09-10 08:52:29

British scientists say they've found some female insects can control the amount of sperm they store in an effort to select the best father for their young. University of Exeter researchers say their findings represent new evidence to explain how some female insects can influence the father of their offspring, even after mating with up to 10 males. The scientists, led by postdoctoral researcher Amanda Bretman, made the discovery during research involving female crickets, which often mate with...

2009-09-08 09:54:21

Females control sperm storage to pick the best father Scientists have found new evidence to explain how female insects can influence the father of their offspring, even after mating with up to ten males. A team from the University of Exeter has found that female crickets are able to control the amount of sperm that they store from each mate to select the best father for their young. The research team believes the females may be using their abdominal muscles to control the amount of sperm...

2009-07-09 09:34:32

Attractive males release fewer sperm per mating to maximize their chances of producing offspring across a range of females, according to a new paper on the evolution of ejaculation strategies. The findings by researchers at UCL (University College London) and the University of Oxford suggest that, paradoxically, matings with attractive males may be less fertile than those with unattractive ones.In a paper to be published in the journal American Naturalist, the team mathematically modeled a...

2008-06-08 16:34:05

"Every sperm is sacred. Every sperm is great. If a sperm is wasted, God gets quite irate," goes the song from Monty Python's movie The Meaning of Life. If the lyrics strike you as funny, it's most likely because calling a sperm cell "sacred" sounds ridiculous when men can produce so many of them. In fact, the average male will produce roughly 525 billion sperm cells over a lifetime and shed at least one billion of them per month. A healthy adult male can release between 40...

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2008-04-23 10:43:05

Variety is the spice of life: too many males, too little time...Female Australian painted dragon lizards are polyandrous - that is, they mate with as many males as they can safely get access to. This promiscuous behavior is often found in species where male quality is dubious and there are high levels of infertility in the male population. Female painted dragons possess the remarkable ability to store sperm inside their reproductive tract that remain viable for a considerable amount of time,...


Word of the Day
mundungus
  • A stinking tobacco.
  • Offal; waste animal product; organic matter unfit for consumption.
This word comes from the Spanish 'mondongo,' tripe, entrails.