Sentences with phrase «sex ratio»

Overall, 35 percent of injuries occurred in women, with no significant change in sex ratio of injuries over time.

Sex ratios in all other treatments contained statistically equal proportions of females and males.

These are split into males and females using the assumed sex ratio at birth.

«In both cases, the offspring of the mice had a heavily male - biased sex ratio,» she says.

The fact that women usually prefer marrying men who are slightly older can shift the availability sex ratio up or down almost overnight.

The numbers of children born by this technique would be very low, so this sex selection would bear no impact on a country's overall sex ratio.

A host of effects produce differences in sex ratios around the world and between racial and ethnic groups.

Because sex ratio is biased toward males, the figure is expressed by dividing male births by total births.

(the genetics of sex ratio are a very interesting story, which i will cover at some point).

This «sex ratio at birth» — stable across generations and ethnic boundaries — may range from 103 to as high as 106 boys for every 100 girls.

Demographic studies since the 1980s have suggested son preference and sex - selective abortions of girls were the main causes of the skewed sex ratio in these countries.

«The research raises the possibility that many other aquatic species could be affected by road salts in sub-lethal ways, not only in terms of altered sex ratios, but potentially in many other traits.»

But a low sex ratio also lowers the living standards of women and causes turmoil in relationships, mainly because men typically have more power in society, which they tend to exercise crudely when there are extra women around.

Hispanic Americans, on the other hand, have the highest sex ratio of any ethnic group in the country — over 1.5 for people in their twenties — mainly because far more men immigrate than women.

«Mosquitofish populations with more females have greater ecological impact: Scientists investigating ecological consequences of sexual dimorphism and sex ratio variation in mosquitofish populations found dramatic effects.»

Brendan Godley at the University of Exeter, UK, and colleagues, analysed 26 years of data to see if fluctuations in temperatures had an influence on sex ratios of turtles in North Carolina.

In other words, the nationwide shift toward conservatism, and even the election of George W. Bush in 2000, was predictable from sex ratio data.

Researchers have found a heavily male - biased sex ratio among crocodiles in Palo Verde National Park in Costa Rica.

The natural sex ratio for the American alligator, for example, is about 0.2, or one male for every five females.

Climate change can meddle with sex ratios of the seven species of sea turtles because their embryos start life without a genetically fixed sex.

Darwin's Rx: natural selection defeats a male - killing bacterial strain and restores a more balanced sex ratio among Samoan blue moon butterflies

According to this so - called adaptive sex ratio adjustment hypothesis, healthy mothers were better off producing sons, who would likely be fit and go on to reproduce, whereas mothers in less prime condition would benefit more from daughters, who would reproduce regardless of their low health status.

Demographically stochastic events are random fluctuations in population variables, such as sex ratios and number of births or deaths.

He saw the famine as a natural experiment for the adaptive sex ratio adjustment hypothesis.

He offered a topic ripe for further investigation: a recent study that claimed a three - to - one male - to - female sex ratio among the crocodiles in the area.

In 2010, the last year in which a census was conducted, Chinese had 118 boys for every 100 girls — far above the natural sex ratio of birth of 105 boys per 100 girls.

Differences in mating behavior and sex ratio between three sibling species of Nasonia.

Mosquitofish were obtained from a California mosquito vector control district, sorted by sex, and introduced into the tanks at five different sex ratios, plus a fish - free reference treatment.

They are the first to estimate sex ratios using a male - specific, transcriptional molecular marker Sox9, a marker of testis development in sea turtles and freshwater turtles.

Giving the spiders antibiotics restored a normal sex ratio, proving that the previous female bias really was Wolbachia «s work (BMC Evolutionary Biology, DOI: 10.1186 / 1471-2148-11-15).

Of those that correlated sex ratios with the mothers» condition at the time of conception, she found that three - fourths supported Trivers and Willard.

Similarly, in countries at war, sex ratios tilt toward boys, presumably because of frequent sex during home leaves and after demobilization.

Political unrest, natural disasters and maternal stress are among a long list of traits suggested to lower the male bias in human sex ratios [4], [5], whereas during the First and Second World Wars in Europe, a more male - biased SSR has been documented [6].

A 1 °C to 2 °C increase can push sex ratios of hatchlings produced to close to 100 %,» Godfrey told New Scientist.

Sex ratio effects on reproductive strategies in humans.

Surveys have shown that paleo is evenly split between men and women — eating real food isn't a male or female thing — but an even sex ratio is still heavily male relative to most other dietary approaches, which tend to skew female.

Switala (1995) took into account the typical sex ratio of harvests in each of the States, the meat yield from carcasses and the 1993 quotas and calculated the availability of 55,000 tonnes of meat, of which 80 % could be supplied by Queensland (approx. 26,000) and New South Wales (approx. 19,000) together.

The fetal sex ratio and metabolic, biochemical, haematological and clinical indicators of severity of hyperemesis gravidarum.

The numbers are even more startling because a warming climate should be pushing croc sex ratios in the other direction.

With her death, the book deal she had made with a major publisher disappeared, and sex ratio theory stayed mainly in the obscure recesses of various academic specialties.

Barber's research suggests, for example, that a high sex ratio generally leads to less violence toward women.

The new study and Kim's 2011 study in South Korea both found a similar sex ratio for autism: roughly three boys for every girl.