Sentences with phrase «sex ratios in»

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

They also found that exposure to the leaf litter from a common trees species, oak, significantly altered the sex ratios in the frog populations and, in some cases, the size of individual females.

Research published in November 2016 showed that sodium chloride can alter the sex ratios in populations of developing frogs.

The sex ratios in productive and unproductive environments were initially similar but quickly diverged, with unproductive lakes becoming increasingly male - dominated.

Sex ratios in sub-Saharan Africa are a bit more balanced, and the sex gaps in education, work outside the home and child mortality are not as large.

Also in this issue: the science of sex ratios in future generations, the real trick to successful negotiations, and the disease that makes people allergic to the most common chemicals in everyday life.

Sex ratios in natural populations of mosquitofish vary considerably from place to place around the world.

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

The financial support came from a National Institutes of Health (NIH) training grant that Weir, who was studying the genetics of sex ratios in mice, had won to fund graduate students — a grant, it turned out, that was intended only for American citizens and permanent residents.

The sex ratio in the overall population is «nothing out of the ordinary,» with roughly one juvenile male for every four juvenile females, says study coauthor Michael Jensen, a marine biologist with the National Oceanic and Atmospheric Administration in La Jolla, Calif..

Owing to a quirk of ant reproductive biology, the female workers are three times more closely related to the queen's female offspring than they are to the males, so, in theory, the female workers should skew the sex ratio in favor of females.

Ecologist Patricia Adair Gowaty at the University of Georgia predicts the paper will become an «instant classic,» calling it «the first time that [changes in sex ratio in birds] have been shown so convincingly.»

In relatively stable societies like the U.S., the most powerful factor determining the balance of men and women is that marriage squeeze, and birth patterns over the past 25 years make it possible to estimate the availability sex ratio in the U.S. through the year 2035.

The birth sex ratio in China is now an alarming 1.13.

Biologists have looked at the sex ratio in animal populations for generations, typically just by counting the males and females in a pack or herd.

To study the sex ratio in humans is more challenging, especially if your goal is to determine how the sex ratio affects social systems.

The highest sex ratio in the world right now — 4.15 — is in Qatar, where thousands of men have immigrated to work on construction and oil projects.

Barber's studies, which often look at patterns in 40 countries or more, have shown the power of the sex ratio in predicting such things as the rate of nonmarital births, the practice of polygyny, and even the likelihood that men will grow facial hair.

You've been looking into the imbalance in the sex ratio in China and the potential long - term consequences that imbalance could have.

Plentiful food sources are consistently linked with a male - biased sex ratio in nonhuman mammals, and a 2008 study found that British women with the best nutrition during conception were significantly more likely to give birth to boys than women with the poorest diet.

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.

Scrotal heat stress effects on sperm viability, sperm DNA integrity, and the offspring sex ratio in mice

Geographic clustering of the secondary sex ratio in Japan: association with demographic attributes

Thus, these results did not support the idea that the biological changes of puberty are a primary motive force in producing the changes in the sex ratio in depression in adolescence.

Not exact matches

The most recent Chinese census shows a sex ratio of 150 boys for 100 girls in subsequent pregnancies.

Meanwhile, in South Korea, so far the only country to have reversed the trend in sex ratios at birth, normative changes related to public policies apparently worked after banning the practice made matters even worse.

And the overwhelming ratio to «lust» books vs. «gift of sex» books is because dealing with lust is much more prevalent in society than enjoying the gift of sex as God intended.

He continued, «Studies performed in later pregnancy beyond the first trimester have shown a slight sex difference in the main level of this hormone, so that female pregnancies tend to have a slightly higher level of this hormone, and we speculated... that if the same sex difference in this hormone level exists in the early part of the pregnancy, and if this hormone is truly related to the occurrence of morning sickness, then we would perhaps expect an altered sex ratio among women suffering from severe nausea.»

«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.»

Other would - be fathers carry a «sex - ratio suppressor» which does the opposite, producing a slight boost in female offspring conceived in the barren dry season.

Van Hooft found that some males carry a «sex - ratio distorter» gene which ensures that more males are conceived in the wet season, when food is abundant, making the fathers fitter and their sperm quality higher.

In a study published in Zoology, FAU researchers are the first to show why and how moisture conditions inside the nest affect the development and sex ratios of turtle embryoIn a study published in Zoology, FAU researchers are the first to show why and how moisture conditions inside the nest affect the development and sex ratios of turtle embryoin Zoology, FAU researchers are the first to show why and how moisture conditions inside the nest affect the development and sex ratios of turtle embryos.

Even if the sex ratio at birth were to normalize tomorrow, Catherine Tucker and Jennifer Van Hook, demographers with Pennsylvania State University's Population Research Institute, recently calculated that fully 10 percent of working - age men in China would still lack a female counterpart in 2050 — and that's assuming that men start marrying women their own age, a change from their current practice of seeking mates a few years younger.

In that year China is expected to overtake Japan as the world's most aging society, and the number of working - age men without female counterparts will peak at 29 million (and that's assuming that the sex ratio at birth begins to drop tomorrow).

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 girlIn 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 girlin 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.

«Furthermore, results of our study highlight the importance of including moisture conditions when predicting embryo growth and sex ratios and in developing proxies of embryonic development.

That's according to Misao Fukuda at the M&K Health Institute in Hyogo, Japan, and colleagues, who found subtle differences in sex ratios of children depending on when a mother entered menarche.

In contrast, the sex ratio of the highland litters remained equal (Nature, DOI: 10.1038 / nature09512).

By observing groups of flour beetles in the laboratory, Melbourne and Alan Hastings, a mathematical ecologist at the University of California, Davis, demonstrated that random variations in sex ratios and physical differences, such as body size, greatly contribute to the overall threat of extinction.

To find out if global warming might skew the sex ratio of hatchlings, Rory Telemeco and his colleagues at Iowa State University in Ames developed a mathematical model to predict the sex ratio of eggs laid at different temperatures.

But just how the birds manage to change that ratio remains a mystery: Sex in birds is determined by which chromosome the egg carries, and each egg starts out with a 50 - 50 chance of being male or female.

He could have hardly guessed that ultrasound would one day contribute to a sex ratio imbalance involving over 160 million «missing» females in Asia and elsewhere.

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.

But Albers says the difference evaporates if you look more closely at sex ratios and success rates in NWO's nine scientific disciplines.

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

To find out who in the colony really controls the sex ratio, Laurent Keller of the University of Lausannne and his colleagues took queens from male - dominated colonies and female - dominated colonies and switched them.

Among his recent findings: When the sex ratio is low (too many women), women are more slender; when women are in short supply, as was the case in the United States in the 1950s, women are more curvaceous, perhaps because they are trying to look the part of traditional wife and mother.

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.

By the time people are in their eighties, however, the sex ratio drops to 0.7 or less.

In a study of divorces in the U.S. from 1896 to 1992, Barber reports that the divorce rate could be predicted remarkably well from the sex ratiIn a study of divorces in the U.S. from 1896 to 1992, Barber reports that the divorce rate could be predicted remarkably well from the sex ratiin the U.S. from 1896 to 1992, Barber reports that the divorce rate could be predicted remarkably well from the sex ratio.