Sentences with phrase «sex ratio are»

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

The persistence of such high sex ratios is puzzling, because it violates Fisher's Principle.

The pivotal temperature is the constant temperature (29 degrees Celsius or 84.2 degrees Fahrenheit) at which 50:50 sex ratio is expected.

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.

Worldwide, the birth sex ratio is generally above one, about 1.07 — nature's way, perhaps, of compensating for the higher mortality rate of males throughout life.

That sounds weird, but a fifty - fifty sex ratio is not always the norm.

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

«Evidence suggests that the temperature - sex relationship found in the laboratory is less tight in nature and verification of sex ratios is often insufficient or absent,» said Wyneken.

The sex ratio is approximately equal [11] and inbreeding levels did not increase over time in the study population [14].

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.

According to the latest census data released Tuesday by Statistics Canada, the national sex ratio is 95.9 men for every 100 women, down from 96.1 men to 100 Canadian women in 2001.

The sex ratio is especially lopsided among Mormon singles.

In this way a robust two hundred and fifty year time - series of incubation temperatures, hatchling sex ratios, and adult breeding sex ratios were derived.

In Japan, female - biased sex ratios were associated with poorer union stability, shorter life expectancy, lower total fertility rates, and higher rates of spontaneous and artificial abortion [106].

The CG consisted of 42 mothers and 35 fathers of 48 typically developing children (males n. 17; females n. 31; sex ratio M / F = 1/1.8) recruited via school nurses, attending regular classes in mainstream schools, with no mental, developmental, or physical disabilities according to school medical records and not receiving ongoing prescription medication.

Not exact matches

«The researchers also found that after taking into account the effect of age and sex, morning people were likely to have lower — and thus generally more healthy — BMI, or body - mass index, a measure of the ratio between height and weight.»

The sex ratio SR (y, t) is shown for DM1 (d, e) and DM2 (f, g) patients and the number of their diagnoses (d, f) and their prescriptions (e, g).

Previous investigations have indicated that the ratio of sex offenders against female children vs. offenders against male children is approximately 2:1, while the ratio of gynephiles to androphiles among the general population is approximately 20:1.

Using phallometric test sensitivities to calculate the proportion of true pedophiles among various groups of sex offenders against children, and taking into consideration previously reported mean numbers of victims per offender group, the ratio of heterosexual to homosexual pedophiles was calculated to be approximately 11:1.

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.

This height / weight ratio, which takes into account a child's age and sex, is the best measure of healthy weight for kids ages 2 and up.

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.»

Besides skewing the sex ratio, the hormone could be disrupting the animals» reproduction, a concern because American crocodiles are already listed as vulnerable, and this part of Costa Rica is a stronghold for the species.

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

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.

FEELING THE HEAT Climate change may skew the sex ratios of sea turtles (loggerhead shown), but that could be a small worry compared with the dangers of overheated nests.

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.

«Sexual dimorphism is very common, as is sex ratio variation.

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 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 girls.

For example, according to the Shettles method, having sex as close to the moment of ovulation as possible is supposed to skew the ratio towards boys: the Y chromosome is smaller, so the reasoning is that Y - carrying sperm swim faster and are first to reach the egg.

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).

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.

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..

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.

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.»

It remains unclear what evolutionary purpose is served by such skewed sex ratios.

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

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.

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.

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 ratio.

A 2010 study conducted in the U.K. found that babies born to two nonsmokers were more likely to be male (birth sex ratio of 1.14), whereas babies born to two smokers were much more likely to be female (birth sex ratio of 0.77).

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