females in Biological News

Caffeine appears to be beneficial in males -- but not females -- with Lou Gehrig's disease

NEW ORLEANSAmyotrophic lateral sclerosis (ALS) is a fatal disease that damages key neurons in the brain and spinal cord. The disease causes progressive paralysis of voluntary muscles and often death within five years of symptoms. Although ALS (Lou Gehrig's disease) was discovered over a century ag...

Caffeine appears to be beneficial in males -- but not females -- with Lou Gehrig's disease

NEW ORLEANSAmyotrophic lateral sclerosis (ALS) is a fatal disease that damages key neurons in the brain and spinal cord. The disease causes progressive paralysis of voluntary muscles and often death within five years of symptoms. Although ALS (Lou Gehrig's disease) was discovered over a century ag...

Study first to pinpoint why analgesic drugs may be less potent in females than in males

ATLANTA -- Investigators at Georgia State University's Neuroscience Institute and Center for Behavioral Neuroscience are the first to identify the most likely reason analgesic drug treatment is usually less potent in females than males. This discovery is a major step toward finding more effective ...

Gene in male fish lures females into sex

A gene has been found in male cichlid fish that evolved to lure female fish so that male cichlids can deposit sperm in the females mouths. A study in the online open access journal BMC Biology reveals that the gene is associated with egg-like markings on the fins of cichlid fishes and uncovers the...

Why do males and females frequently differ in body size and structure?

RIVERSIDE, Calif. As even the most casual observer of nature knows, males and females frequently differ in body size, form and structure. But how these differences have developed a topic studied for decades by evolutionary biologists is not as clear. A new scholarly book now neatly brings t...

Reproductive life of male mice is increased by living with females

Living with a female of its species can extend the reproductive life of a male mouse by a dramatic 20 percent, according to a study reported at the online site of the journal Biology of Reproduction . In the research, conducted by a team at the University of Pennsylvania School of Veterinary M...

CU study reveals why starling females cheat

While women may cheat on men for personal reasons, superb starling females appear to stray from their mates for the sake of their chicks, according to recent Cornell research published in the Proceedings of the Royal Society of London B. The study found that superb starling females (Lamprotornis...

Zebra finch males prefer females with exaggerated maternal traits

Researchers have demonstrated that learning about the appearance of their parents may give birds a preference for mates with exaggerated parental traits, rather than traits that more exactly match those of their parents. Such learned mate preferences may help drive the evolution of exaggerated trai...

Choosy females make colourful males

Female fish prefer brightly coloured males because they are easier to see and are in better shape concludes Dutch researcher Martine Maan following her study of fish speciation in the East African Lakes. Environmental variation subsequently leads to differences in preference and eventually to speci...

Brain differences could explain why males and females experience pain relief differently

A study conducted by investigators at Georgia State University and the Atlanta-based Center for Behavioral Neuroscience (CBN) reports that anatomical and functional differences in the brain may explain sex differences in the experience of pain and in the effects of certain drugs on pain. The fi...

Male rivalry increases when females at most fertile, say researchers

Men become more jealous of dominant males when their female partner is near ovulation, researchers at the University of Liverpool have found. Previous studies have found that women's preferences for male physical appearance vary according to their fertility status. During ovulation women tend to...

Male elephants woo females with precise chemistry

The exact chemical blend of a pheromone emitted by older male elephants in musth influences both a female elephant's interest in mating and how other surrounding elephants behave, a new study has found. The researchers at Oregon Health & Science University and the University of Auckland in N...

Leicester research paves way for first use in Europe of an insect to fight invasive plant

...gists established that the Japanese Knotweed in Britain was one the biggest females in the world- a clone of cuttings brought into Britain in the 1850s. Costs ...l introduction by P. von Siebold in the 1850s making it one of the biggest females in the world! Michelle was also able to show that small mutations in th...

Parasitic worms make sex worthwhile

...rasite makes sex advantageous for the snail, whose females favor asexual reproduction in the absence of paras...y Ph.D. student and lead author of the paper. "The females that reproduce asexually aren't as exposed to the ...ts) and absent elsewhere (cold spots). "Asexual females can have a very large reproductive advantage, as a...

New research finds possible genetic link to cause of pregnancy loss and disorders

...ps, there were only one or two pups that survived to term in the litters of females that had one copy of Bub1," said Venkatachalam. "So this was unusual when w...mosome or an egg with a missing chromosome. The team linked the issue to females by mating both a male with one bad copy of the gene with a normal female an...

New theory on why male, female lemurs same size

...females. Size is an advantage for males that guard females to keep other males from mating with them, and evo...le, while also freeing the male to mate with other females during the brief time they are available. "If t...ual receptivity was very brief and where males and females were the same size. This was true both for lemur s...

Seals quickly respond to gain and loss of habitat under climate change

...to be the abundant local food resource and extensive physical habitat that allowed rapid expansion after the initial founder event, and a tendency for females to return to annual breeding sites in this species. When the ice expanded again 1,000 years ago, the seals returned to their origins but in much s...

Spread your sperm the smart way

... the Arctic charr, males with privileged access to females produce ejaculates of lower fertilising quality th...and Experimental Biology), says: "In some species, females mate with many different males. Each male's sperm ...t females. The more attractive a male is, the more females will be willing to mate with him, reducing the val...

Male seahorses like big mates

... been thought to have conventional sex roles, with females choosing mating partners and males competing for t...clear preference for larger partners. In contrast, females were significantly less active and showed ambiguou...s conclude: "The strong male preferences for large females demonstrated here suggest that sexual selection ma...

Key to evolutionary fitness: Cut the calories

...nds. Also, as the hares were provided with plentiful food, there could be no limitation of energy turnover due to food availability. The way that females regulated their energy expenditure according to pup demand and their own fat reserves but did not exceed certain levels fitted with the group's theory...

Female human embryos adjust the balance of X chromosomes before implantation

...ell as for embryo stem cell research. Males and females have two sex chromosomes: X and Y. While females have two X chromosomes and no Y chromosome, males ...me is much larger then the Y chromosome, males and females also differ in their numbers of genes and gene exp...

UTSA wins San Antonio Area Foundation grant to further chlamydia research

...ntion; the disease is most prevalent among teen girls. The infection rate in Texas is slightly higher than the national average. Nearly 17% of Texas females in the 15-19 age group test positive for the infection. However, experts believe even more chlamydia cases exist than are reported, because the dis...

Mate selection: How does she know he'll take care of the kids?

...hat males showcase their best qualities to attract females for mating isn't a new one, nor is the idea that t...but do not have to, provide parental care because females will pick up the slack. The Yale researchers focused on those species, like stickleback fish, where females cannot pick up the slack and males who do not prov...

Why do we choose our mates? Ask Charles Darwin, prof says

...oriously-colored male peacocks, that lions get the females of their choice or that humans spend hours primpin...s explains. "He discovered that birds especially females had preferences and that they did not just choose...elieved this is due to beauty of the plumage, that females usually selected the most colorful males. "Tha...

Chemical in blood may explain susceptibility to bladder pain

... a review paper in the April issue of the journal Psychotherapy and Psychosomatics in which he suggested that traumatic events experienced by pregnant females might transmit to fetuses a genetic change associated with the stress response. Buffington suggests that such a genetic change would mean offsprin...

Not 1, but 2 kinds of males found in the invasive round goby

... call "sneaker" males little males that look like females and sneak into the nests of the larger males. ...at less while guarding their nests, and attracting females while providing care can be difficult, males in so...to mate, Marentette explains. Instead of courting females and protecting the young, some males will parasiti...

Hidden genitalia in female water striders makes males 'sing'

...enitalia from males' forceful copulatory attempts, females of an Asian species of water strider seem to "win"...evolutionary arms race between the sexes. Instead, females only expose their genitalia for copulation after m...males, result in different traits in males than in females (for example, different body sizes to guarantee th...

Hypertension among lower-status employees lingers well into retirement

...erall, the link between higher-status occupation and lower prevalence of hypertension was stronger for male seniors than for female seniors. Moreover, females in professional positions had more hypertension than female managers, whereas male professionals did not have more hypertension than male managers. Le...

Study finds colorectal cancer rates increasing worldwide

... 2009A new study finds colorectal cancer incidence rates for both males and females increased in 27 of 51 countries worldwide between 1983 and 2002, and points...98-2002. They found colorectal cancer incidence rates for both males and females increased for 27 of 51 cancer registries considered in the analysis between...

Biologists devise unifying framework to explain evolutionary puzzles

...tra-pair parentage might result from reproductive "agreements" and transactions between breeding individuals, instead of being the result of males and females "cheating" on each other. Akay is part of a group of leading theoretical biologists, ecologists, and mathematicians who will gather at the National...

Biologists consider unifying framework to explain evolutionary puzzles

...tra-pair parentage might result from reproductive "agreements" and transactions between breeding individuals, instead of being the result of males and females "cheating" on each other. Akay is part of a group of leading theoretical biologists, ecologists, and mathematicians who will gather at the National...

When evolution is not so slow and gradual

...r new environments. The researchers found that the females had altered their reproductive effort to match the.... In the environment where predators were present, females produced more embryos each reproductive cycle. Thi...ond chance to reproduce. In less dangerous waters, females produced fewer embryos each time, thus expending f...

Study finds genetic links to age of first menstrual period and menopause

... Boston, MA -- Newly identified gene variants associated with the age at which females experience their first menstrual period and the onset of menopause may help shed light on the prevention of breast and endometrial cancer, osteoporosi...

Genes that influence start of menstruation identified for first time

...orted the age at which they reached menstruation of between nine and 17 years. The two genes identified were on chromosomes nine and six. One in 20 females carry two copies of each of the gene variations which result in menstruation starting earlier, and they will start menstruating approximately four and...

The importance of being helpful -- Cooperative cichlids boost their own reproductive success

...n an act of reciprocal altruism, these subordinate females actually benefit from the care-giving they offer a... help to raise the offspring of unrelated dominant females (a form of alloparental care). Studying small grou... for reciprocation among cichlids are high, as the females lay eggs about every second weekthere was no corre...

Genital stimulation opens door for cryptic female choice in tsetse flies

...entist at the Smithsonian Tropical Research Institute and professor of biology at the University of Costa Rica. Cryptic female choicethe ability of females to control which sperm reaches their eggs during and after the mating processleads to rapid evolutionary changes in genital structure and is probably ...

Mothers give interloper's offspring a head start in life

...ue tits which are usually socially monogamous, but females commonly mate outside their pair to produce clutch... extra-pair offspring are laid earlier or even why females choose to mate with extra-pair males," said Dr Mag...explanation could be in the timing of copulations. females may engage in extra-pair matings to guard against ...

UCLA scientists discover ultrasonic communication among frogs

...something brand-new. We were there a week and saw only two other people." Arch and Narins studied male frogs. In the majority of frog species, the females do not vocalize, and when they do, they do so less frequently than males, Arch said. ...

Penn State entomologists seek fungus to blunt mosquitoes' sense of smell

...sfer malaria parasites to humans when the female mosquitoes bite humans for blood meals to allow them to lay eggs. Male mosquitoes and non-reproducing females sip nectar or other sources of sugar for energy. Mosquitoes do not have noses, but smell using their antennae. The researchers will infect batches o...

Late motherhood boosts family lifespan

..., "there have been several studies that show a number of species, including humans, are able to reproduce late without medical intervention and those females live longer." Other studies found that late menopause also is associated with women having prolonged fertility and longevity. "There is a genetic ...