Tag: "selection" at biology news

Bigger horns equal better genes

...of ageing, which is the idea that, because natural selection weakens with age, genetic mutations have effects that accumulate over time. Therefore, differences in genetic quality become more apparent as an organism ages. Coltman noted that his study, which incorporated genetic samples from more than 150 ib...

Columbine flowers develop long nectar spurs in response to pollinators

...ed a co-evolutionary "race" to explain how natural selection might account for the evolution of very long nectar spurs in flowers, said Hodges. "In Darwin's race, plants with the longest spurs and pollinators with the longest tongues [to tap the flowers' nectar] would be favored by natural selection, and--in a...

Research shows cord blood comparable to matched bone marrow

...provide guidelines to transplant physicians on the selection of the best donor for children with leukemia. Remarkably, mismatched cord blood performed as well as matched bone marrow as measured by leukemia-free survival rates, providing the degree of mismatch was limited and the number of cord blood cells ava...

Physicist cracks women's random but always lucky choice of X chromosome

...r Nicodemi has found an explanation for the random selection based on thermodynamics. Research has already shown that at the key moment in this process both X chromosomes are brought close together within the cell. The Warwick researcher paper says that what happens next is that material for a "protein plug" t...

454 sequencing identifies HIV drug resistance at early stage

...tant HIV strains which can grow rapidly under drug selection pressure and lead to therapy failure. This retrospective study clearly shows that even resistance mutations present at the 1% level lead to premature failure of therapy” explained Michael Kozal, M.D. the senior author on the study. “In the future, h...

The mouflons of the Kerguelen archipelago

... observed the opposite.” The effect of natural selection diversity to be attributable to genetic mutation, and the Islands are much too isolated to have undergone migrations. “This variety can be explained by elimination, over the generations, of individuals with low genetic diversity. In small isolated...

Mule deer moms rescue other fawns

...s traditional explanations that parental care, kin selection or reciprocity play a part in the defence of fawns other than their own. But while the study's findings seem to point to mule deer as superior mothers, the motivation for looking out for other fawns is likely based not on altruism but on simple survi...

'Personality-gene' makes songbirds curious

...s in populations, which would result from changing selection pressures on different personality types. ...

How the brain's backup system compensates for stroke

...remotor cortex (PMd), which is known to govern the selection of an action. The PMd is mirrored in the two brain hemispheres, and the left-hemisphere PMd is dominant in such motor control function. Researchers had known that after a stroke damages one side of the brain and paralyzes a limb, the PMd in the intac...

Amphibians in losing race with environmental change

... conditions. Through genetic variation and natural selection pressures, some species or populations will be abl...bians to a variety of damaging agents." Natural selection and species adaptation may, in time, allow amphibians to react to and recover from the new environme...

Why do oysters choose to live where they could be eaten?

...uccess. However, in the case of oyster larvae, the selection of a place to call home can be a life or death decision. According to an article in the May edition of Ecological Monographs, a team of scientists has found that despite the risk of being eaten by cannibalistic adults, oyster larvae choose to settle...

Maggots rid patients of MRSA

...od, possibly due to overuse of antibiotics and the selection of broad rather than narrow-spectrum antibacterial agents. This led to their first study, funded by Central Manchester and Manchester Children's University Hospitals NHS Trust (CMMC) Chairman's Prize Award. They treated 13 patients, aged 18-80 yea...

Scientists: As rainfall changes, tropical plants may acclimate

... " ?This does not support the idea that natural selection has caused species to diverge into highly specialized niches for nitrogen consumption," the PNAS paper says. That's a positive sign considering that as the Earth warms, some areas of the tropics are widely expected to be wetter, some drier. So, at...

Survival of the rarest: Fruit flies shed light on the evolution of behavior

...een able to explain why it persists, since natural selection ensures that only the best survive," says Sokolowski, who holds a Canada Research Chair in Genetics. "In some cases, individuals with characteristics that differ from the rest of the population are more likely to survive since their rarity makes them...

Latent memory of cells comes to life

...y a slow and gradual process that involves natural selection operating over many generations. Sometimes however, dramatic and very sudden changes are observed in one individual in the absence of any kind of change to the DNA. This happens in fact in all of us as our body develops: cells with identical gene...

DNA analysis suggests under-reported kills of threatened whales

...Baker and his colleagues conducted 12 surveys at a selection of shops selling whale meat in certain Korean coastal cities from 1999 to 2003 and collected 289 samples. They initially expected to find that many of the cuts of meat they purchased would come from a small number of whales, but when they used DNA pr...

Sandia researchers take new approach to studying how cells respond to pathogens

...s. The other combines cell preparation steps, cell selection and sorting followed by analysis of protein content in the selected cell subpopulations. "In effect, we are taking many work-horse technologies such as confocal microscopy, flow cytometry and immunoassays and combining them into one compact, minia...

Ancient genes used to produce salt-tolerant wheat

...t began when the CSIRO team used a highly accurate selection method -- based on their understanding of how plants tolerate salt -- to identify wheat varieties that could cope with higher salinity. They were particularly interested in the premium-priced durum wheat, which is much more salt-sensitive than bread ...

Study suggests some drug resistance to influenza B medications

...al dosing for these viruses will lead to increased selection of viruses with high-level resistance.? “Influenza viruses evolve rapidly and nimbly, which compels ongoing investigation of antiviral therapies that use alternative mechanisms of action and target different points in the viral life cycle. The emer...

Remote sheep population resists genetic drift

...a. "We think this has happened because natural selection is more important to the evolutionary process than is commonly believed," he added. Genetic diversity refers to the total amount of possible gene combinations that a mating male and female couple can produce. Scientists believe greater genetic div...

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