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Tag: "variation" at biology news

Researchers add to understanding of how brain cells communicate

...olecules. They used computer modeling to show that variation in how ions interact with receptors combined with variation in the structure of receptors is responsible for specialization of receptor function. "This resea...

Study suggests evolutionary link between diet, brain size in orangutans

...is brings us closer to a good ecological theory of variation in brain size, and thus of the conditions steering cognitive evolution," he said. "Such a theory is vital for understanding what happened during human evolution, where, relative to our ancestors, our lineage underwent a threefold expansion of brain s...

International team analyzes human genetic variation in key immune region

...ers today unveiled a detailed map of human genetic variation within the major histocompatibility complex (MHC),...cientific collaboration to catalogue human genetic variation on a genome-wide scale. The latest findings, particularly the analyses of the HLA gene region, provi...

Researchers make progress in studying genetic traits of India-born populations

...udy represents the largest study of Indian genetic variation performed to date, in terms of the total number of sites in the human genome that were surveyed. The researchers found that populations from India, and more generally, South Asia, make up one of the major human ancestry groups, with relatively ...

Recurrence of a flu pandemic similar to infamous 1918 flu could kill 62 million

...t so much of the cross-country and cross-community variation would be related to economic status." The researchers caution that per capita income only explains about half of the wide mortality range seen among--and in many cases within--particular countries. Other unique community attributes that influenced...

On the golf tee or pitcher's mound, brain dooms motion to inconsistency

... practice and training is that they can reduce the variation in the mind's abilities, but they don't change the variable way the mind plans motion. An analogy might be to doing math problems. Someone who has studied will find it easier to solve a new problem than someone who has not prepared. Given the endem...

Wolves are suffering less from inbreeding than expected

... at several places to measure the level of genetic variation of individuals. Together with the previous analyse...g coefficients the new direct m easures of genetic variation delivered some surprising results. - For each level of inbreeding it appears to be the wolves with...

New technology used to construct the first map of structural variation in the human genome

... blindness, and many other diseases. They lead to variation in gene expression levels and may account for a large amount of phenotypic variation among individuals and ethnic populations, including differential responses to drugs and environmenta...

History-hunting geneticists can still follow familiar trail

...ld has worked from the premise that the more mtDNA variation you saw, the larger the population was that carrie... correlation between mitochondrial DNA and genetic variation in a way that has never been done before," said Marc Allard, an associate professor of biology at Ge...

Study finds the air rich with bacteria

...t location was not as strong a source of microbial variation as time and weather. Specifically, the time of the year during the 17-week testing period was the most significant source of variation, followed by atmospheric conditions. For example, warmer and dryer conditions led to increased amounts of spore-for...

Dragonfly's metabolic disease provides clues about human obesity

...makes up 60 percent of their body mass. The large variation in muscle output was intriguing because natural selection, over time, would weed out the submissive, poor flyers if the trait were genetically based. When the researchers looked in the gut of the dragonflies with poor muscle output, they found paras...

Pleasure and pain: Study shows brain's 'pleasure chemical' is involved in response to pain too

...lf-rated pain and emotional response. This kind of variation may help explain the major variation between individuals who are exposed to addictive drugs ?some become addicted to the pleasures of the...

Does natural selection drive the evolution of cancer?

...umor cells. The first requirement is that there be variation in the population. This variation is evident in tumors, which are a mosaic of many different genetic mutants. The second condition...

Genetic study of Neanderthal DNA reveals early split between humans and Neanderthals

...370,000 years ago. (Researchers found some genetic variation between the two species, which the team attributes to the ancestral population.) Both lines co-existed in Europe and western Asia until about 30,000 years ago. The team used DNA extracted from a 38,000-year-old Neanderthal specimen from Vindija, Cr...

Why do insects like to eat some plants more than others?

... ecologists typically attribute the differences to variation in the nutritional quality or defective chemistry of plant tissues. However, the researchers found that cactus-feeding insects chose host plants based on how the plants allocated resources between growth and reproduction. "The crux of our findings...

Mapping the mouse genome

... HS, and 0.62 cM/Mb for RI. They also saw a lot of variation in recombination rate across the genome, between the two study groups, and between the sexes. In fact, when calculating rates separately for male and female HS mice, they confirmed results seen previously for humans, that the average autosomal (non-s...

A buffet for early human relatives

...seasonally and from year to year. The year-to-year variation in Paranthropus' diet "might reflect yearly differences in rainfall-related food availability," the study's authors write. "Another possible explanation is that these individuals were migrating between more wooded habitats and more open savannas." ...

Researchers link ocean organisms with increased cloud cover and potential climate change

...pment of clouds there ?and may account for most of variation in the area's cloud cover. "If a lot of particles form because of isoprene oxidation, you suddenly have a lot more droplets in clouds, which tends to make them brighter," Nenes explained. "In addition to becoming brighter, the clouds can also h...

Edible coatings will be the packaging of the future

...us, those films with sorbitol plastifier underwent variation in their mechanical properties, i.e. their flexibility; while those containing glycerol did not alter their composition. Once the ideal plastifier for the coating was determined, it was observed that, in order to improve malleability, it was necessar...

Why do some queen bees eat their worker bee's eggs?

... since she has mated with multiple males, ensuring variation in the species. According to this theory, a specie... social behavior. Social insects, with their great variation in kinship, have been a key test bed of the theory, and the theory has revolutionized our understan...

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