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Latest Female Stories

2014-06-17 13:41:26

University of Texas at Arlington A UT Arlington research team says their study of genetic information from more than 4,000 beetle species has yielded a new theory about why some species lose their Y chromosome and others, such as humans, hang on to it. They call it the "fragile Y hypothesis." The biologists' idea is that the fate of the Y chromosome is heavily influenced by how meiosis, or the production of sperm, works in an organism. They believe the size of an area where X and Y...

First Sex Determining Genes Appeared In Mammals Some 180 Million Years Ago
2014-04-24 03:55:04

Swiss Institute of Bioinformatics This news release is available in French and German. Man or woman? Male or female? In humans and other mammals, the difference between sexes depends on one single element of the genome: the Y chromosome. It is present only in males, where the two sexual chromosomes are X and Y, whereas women have two X chromosomes. Thus, the Y is ultimately responsible for all the morphological and physiological differences between males and females. But this has not...

2013-11-04 10:27:57

Female guppies in Trinidad seek rare males as mates When it comes to choosing a mate, female guppies don't care about who is fairest. All that matters is who is rarest. Florida State University Professor Kimberly A. Hughes in the Department of Biological Science has a new study just published in the journal Nature that is the first to demonstrate a female preference for rare males using an experiment in a wild population, rather than a laboratory setting. This study of genetic...

Male Guppies Reproduce Even After Death
2013-06-13 11:37:08

University of California - Riverside UC Riverside-led research team finds posthumous reproduction in guppies because sperm of dead males survive inside females for at least 10 months Performing experiments in a river in Trinidad, a team of evolutionary biologists has found that male guppies continue to reproduce for at least ten months after they die, living on as stored sperm in females, who have much longer lifespans (two years) than males (three-four months). "Populations that are...

Competition Of Males Over Females
2012-10-25 12:18:31

An evolutionary engine of genital evolution When a female mates with several males, these will compete over the fertilization her eggs. This is an important evolutionary force that has led to the evolution of a diversity of male sexual organ morphologies. This is revealed in a study of seed beetles published today in the leading scientific journal Current Biology. In higher plants, the influential classification system developed by Carl von Linnaeus relied on the fact that the...

They Call It 'Guppy Love'
2011-11-25 04:34:35

UCLA biologists solve an evolution mystery Guppies in the wild have evolved over at least half-a-million years – long enough for the males' coloration to have changed dramatically. Yet a characteristic orange patch on male guppies has remained remarkably stable, though it could have become redder or more yellow. Why has it stayed the same hue of orange over such a long period of time? Because that's the color female guppies prefer. "Sometimes populations have to evolve just to...

2011-08-08 12:11:31

Scientists at the University of Liverpool have found that male fruitflies experience a type of 'paranoia' in the presence of another male, which doubles the length of time they mate with a female, despite the female of the species only ever mating with one male. Females in many species of animal have multiple mates and males have evolved particular reproductive characteristics to ensure their sperm are successful when in competition with the sperm of other males. Adaptations include physical...

2011-03-25 11:18:42

Researchers from Osaka University and the National Institute for Basic Biology, Japan, have found a highly significant connection between the molecular mechanisms underlying genetic and environmental sex determination. The scientists report in the open-access journal PLoS Genetics the identification of a gene responsible for the production of males during environmental sex determination in the crustacean Daphnia. Ways in which an individual organism's sex is determined are diverse among...

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2010-12-09 09:15:00

A team of reproductive scientists have successfully produced both male and female mice using two different fathers, according to a study published online Wednesday in the journal Biology of Reproduction. According to a December 8 press release from Biology of Reproduction publishers the Society for the Study of Reproduction (SSR), the research "could be a step toward preserving endangered species, improving livestock breeds, and advancing human assisted reproductive technology (ART). It also...

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2010-07-21 11:31:31

Study on guppies sheds light on long-term costs of early rapid growth and weight gain University of California, Riverside biologists working on guppies "“ small freshwater fish that have been the subject of long-term studies "“ report that rapid growth responses to increased food availability after a period of growth restriction early in life have repercussions in adulthood. Based on their experiments, the biologists found that female guppies that grew rapidly as juveniles...


Word of the Day
endocarp
  • The hard inner (usually woody) layer of the pericarp of some fruits (as peaches or plums or cherries or olives) that contains the seed.
This word comes from the Greek 'endon,' in, within, plus the Greek 'kardia,' heart.
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