Science

Revealed: the aftershave that triggers female sex hormones

E4y.net

Although it has long been debated whether humans can actually communicate via pheromones – the chemical signals secreted by animals to help find a mate – researchers have found that scent of Hedione generates ‘sex-specific activation patterns’ in the nasal tissue which links to the brain.

It is the first time that a scent has been known to activate the pheromone receptor VN1R in humans.

“These results constitute compelling evidence that a pheromone effect different from normal olfactory perception indeed exists in humans,” says scent researcher Prof Hanns Hatt fro, Ruhr-Universität Bochum in Germany.

Hedione (chemical name methyl dihydro-jasmonate) – derived from the Greek word “hedone”, for fun, pleasure, lust – has a pleasant fresh jasmine-magnolia scent and is used in many perfumes.

It is synthesised from the organic compound methyl jasmonate which was discovered in 1957 and which is important in plants for seed germination, root growth, flowering, fruit ripening, and senescence.

Dior was the first perfume house to use the chemical in its men’s fragrance Eau Savage in 1966 and it was so successful that many women adopted it as their own perfume, leading to the introduction of a similar female version, Diorella in 1972.

Since then Hedione has cropped up in First, by Van Cleef & Arpels; Chamade by Guerlain; Chanel no. 19; L’Eau d’Issey by Issey Miyake, Angel by Thierry Mugler, Blush by Marc Jocobs, Paco by Paco Rabane and CKOne.

“60 per cent of the time it works every time”: Brian Fantana from Anchorman wears Sex Panther (by Odeon)

To find out if scent could have an impact on the brain, the scientists analysed brain activity when a person smells Hedione.

They compared the results with the effects triggered by phenylethyl alcohol, a traditional floral fragrance.

Hedione activated brain areas in the limbic system significantly more strongly than phenylethyl alcohol. The limbic system is associated with emotions, memory and motivation.

But more significantly, Hedione also activated a specific area of the hypothalamus in women which is known to promote sexual responsiveness by flooding the body with sex hormones.

The science of sexiness: why some people are just more attractive

Why marathon runners are likely to be smarter

In animals, pheromones are known to trigger the same response. Mice have around 300 different genes for pheromone receptors but scientists believe that there are only five which still function in humans.

Most mammals also have a special organ located at the base of the nasal septum which picks up pheromones. According to current research this organ fulfils no function in humans anymore. Yet the new research suggests that the area still works and can be stimulated by Hedione.

“In the next stage, we want to find out which physiological and psychological parameters are affected when Hedione activates the pheromone receptor,” added Prof Hatt.

“We have already launched the relevant studies. But we also have to search for scent molecules in bodily secretions, which resemble Hedione and activate the receptor. With its help, humans could actually communicate with each other.”

The research was published in the journal NeuroImage.

E4y.net Info@e4y.net

VIDEO: Keeping tabs on basking sharks

E4y.net

The seas around parts of Britain are thought to be home to dozens of basking sharks at this time of year.

However, due to their elusiveness, scientists know very little about them.

With hunting, fishing and climate change threatening their survival, scientists are now hoping to learn more by tagging the huge animals.

Nina Warhurst reports from Newquay.

E4y.net Info@e4y.net

Sex offending is written in DNA of some men, Oxford University finds

E4y.net

“What we have found is high quality evidence from a large population study that genetic factors have a substantial influence on an increased risk of being convicted of sexual offences.

“At the moment genetic factors are typically ignored when it comes to making risk assessments of those at high risk of sexual offending.

“Many of the families we are talking about may already be known to social services for other reasons, and if we can predict those at high risk of offending with greater accuracy then it may be possible to shape these interventions and target education and preventative therapies where they could do the most good.”

Britons still live in Anglo-Saxon tribal kingdoms, Oxford University finds

Violent crime surges 16pc in new figures

Why you really do get that from your father

The study analysed data from all 21,566 men convicted for sex crimes in Sweden between 1973 and 2009.

Having a brother convicted of a sexual offence raised the risk of a man also being convicted of a sex crime by five times, from 0.5 per cent, to 2.3 per cent. Fathers of convicted sex offenders were also four times more likely to have also carried out a sexual assault.

In February it emerged that Jimmy Savile’s brother Jonny had also molested women at a mental health home.


Jimmy Savile’s brother was also found to have been a sexual predator

The researchers found that half-brothers of sex offenders were far less likely to carry out sex attacks than full brothers, even if they had grown up in the same household, suggesting that a shared environment had little impact.

Genetic factors are already recognised as influencing normal sexual behaviour such as arousal, desire and sexual preference. Although it is not clear which genes are responsible for raising the risk, the academics suggest that those linked to increased impulsivity, egotism and decreased intellectual ability could be responsible.

“Importantly, this does not imply that sons or brothers of sex offenders inevitably become offenders too,” said Niklas Langstrom, Professor of Psychiatric Epidemiology at the Karolinska Institute in Sweden.

“But although sex crime convictions are relatively few overall, our study shows that the family risk increase is substantial.

“Preventative treatment for families at risk could possible reduce the number of future victims.”

However the researchers ruled out the possibility of creating a biological test to for sex offenders or screening out the risk in babies born through IVF.

Figures released in January show that 48,934 sexual offences were recorded by police last year, a 19 per cent rise from 2013. The annual Victim Crime Survey suggests around 1.3 per cent of people have been the victim of a sexual crime in Britain, a similar percentage as in Sweden.

The National Organisation for the Treatment of Abusers (NOTA), a charity which looks at ways to prevent sexual offending, said that targeting those at risk of committing sex crimes could prevent attacks.

“The possibility of carefully targeted interventions and support for families in which the relative risks are higher is an exciting prospect,” said a spokesman for NOTA.

Dr Rajan Darjee, a consultant forensic psychiatrist based in Edinburgh, said many sex offenders have underlying psychological problems such as impulsivity, problematic attitudes to children and difficulties relating to others.

“Genes influence brain development and brain functioning underpins psychological functioning, so it should not be surprising to find that genetic factors play a role in sexual offending.

“The fact that genes play such a role does not mean that a person is less responsible for their offending or that offending is inevitable in someone at higher genetic risk, it just emphasises that genes are an important part of a complicated jigsaw.”

The research was published in the International Journal of Epidemiology.

Studying Adam Lanza: is evil in our genes?

Life of crime is in the genes, study claims

E4y.net Info@e4y.net

Painting, drawing and sculpting in old age may protect against dementia

E4y.net

However those who had taken part in arts were 73 per cent less likely to have suffered memory or thinking problems. Those who crafted were 45 per cent less likely to have mild cognitive impairment, while socialising lowered the risk by 55 per cent. Those who regularly used the internet or a computer reduced their risk of memory problems by 53 per cent.

“As millions of older adults are reaching the age where they may experience these memory and thinking problem called Mild Cognitive Impairment (MCI), it is important we look to find lifestyle changes that may stave off the condition,” said study author Dr Rosebud Roberts of Mayo Clinic.

“Our study supports the idea that engaging the mind may protect neurons, or the building blocks of the brain, from dying, stimulate growth of new neurons, or may help recruit new neurons to maintain cognitive activities in old age.”

Hobbies ‘improve brain power in old age’

Elderly who lose interest in pastimes could be at risk of Alzheimer’s Disease

Life begins at 70: Pensioners discover extreme hobbies in their twilight years

There are around 850,000 people currently suffering from dementia in Britain and the figure is expected to rise to one million by 2025. One in six people aged 80 and over have dementia.

Around 60,000 deaths a year are directly attributable to dementia and the Alzheimer’s Society has calculated that delaying the onset of dementia by five years would reduce deaths directly attributable to dementia by 30,000 a year.

Dr Clare Walton, Research Manager at Alzheimer’s Society, said: “Although this study looks at mild cognitive impairment rather than dementia, it does add to previous evidence that keeping your brain active during life with arts, crafts and social activities might reduce the risk of developing memory problems.

“The inclusion of computer use, such as online shopping and gaming, in this study is interesting but more research is needed to determine whether regular computer use has any long-term effects on memory.”

Dr Laura Phipps from Alzheimer’s Research UK, said: “This study adds to previous evidence suggesting that staying mentally active as we age can help to maintain memory and thinking skills.

“While this study looked at mild cognitive impairment, a condition which can precede dementia, the researchers did not look at the benefits of arts and crafts in relation to dementia.

We do know that eating a healthy diet, exercising regularly, not smoking, and keeping blood pressure and weight in check can all help to reduce the risk of dementia.”

The research was published in the Neurology, the journal of the American Academy of Neurology.

E4y.net Info@e4y.net

Short people more likely to develop coronary heart disease

E4y.net

It occurs when the arteries that supply blood to the heart muscle become narrowed due to a deposition of fatty material in the walls of the arteries.

If a blood clot forms over the plaque then the artery can become completely blocked suddenly giving rise to a heart attack.

The researchers looked at genetic data from 200,000 people and found that those parts of the DNA which determined height could be correlated to the chance of developing coronary heart disease.

“The more height increasing genetic variants that you carry the lower your risk of coronary heart disease and conversely if you were genetically shorter the higher your risk,” said Dr Christopher Nelson, a researcher and lecturer from the University of Leicester.

Professor Samani added: “While we know about many lifestyle factors such as smoking that affect risk of coronary heart disease, our findings underscore the fact that the causes of this common disease are very complex and other things that we understand much more poorly have a significant impact.

“While our findings do not have any immediate clinical implications, better and fuller understanding of the biological mechanisms that underlie the relationship between shorter height and higher risk of coronary heart disease may open up new ways for its prevention and treatment.”

The research was published in the New England Journal of Medicine.

E4y.net Info@e4y.net

The science of sexiness: why some people are just more attractive

E4y.net

Probably the most important is facial symmetry. Having a face which is equal on both sides is a biological advert which tells prospective partners that good genes will be found in this body.

Lopsidedness is thought to reflect how development in the womb has been derailed by general poor health, bad DNA, alcohol or tobacco use.

Facial symmetry is also linked to agreeableness, extraversion and conscientiousness, so good looking people generally find it easier to make friends and hold down jobs.

It is why so many people are choosing plastic surgery to straighten noses, and even-up lopsided grins. However, biologically, they are cheating their partners, as they will still pass on their wonky genes no matter what they look like from the outside.

And the importance of symmetry does not stop at facial features.

Studies have also shown that women partnered to men with symmetrical bodies have the most orgasms, and those with symmetrical breasts are more fertile than those less evenly endowed.

Even female swallows prefer males with symmetrical tail feathers as they hunt for superior genetic quality and developmental stability.

Symmetrical faces like David Beckham are more attractive

Finger length

While many women might be looking for the tell-tale signs of a wedding ring, research suggests men’s hands can reveal a whole lot more.

In recent years scientists have discovered that there is an intriguing link between finger length and the levels of testosterone that a man was exposed to while still in the womb.

The longer the ring finger is in comparison with the index finger, the more testosterone was present.

That’s important because high levels of testosterone are linked to high sperm counts, increased fertility, good cardiovascular health and better genes. People with longer ring fingers are also likely to have symmetrical faces.

But before you start looking for men with extraordinarily long ring fingers, bear in mind that Oxford University discovered that they are likely to be more promiscuous. In contrast those whose fingers are a similar length are more likely to seek long-term relationships and stay faithful.

A longer ring finger indicates increases testosterone

Blonde hair

This one stumped even Darwin, who tried to discover why gentlemen prefer blondes, and eventually gave up, after finding there was no overall preference for the fairer sex.

The blonde hair and blue eye combination found in Caucasions is thought to have evolved among northern European tribes around 11,000 years ago.

For tribes who were venturing ever further north with the retreating ice sheets, being blonde would have bestowed an evolutionary advantage. The loss of pigmentation in the skin allows deeper penetration of ultraviolet light needed to synthesise vitamins which were essential for good health. So blondes were more likely to be healthier and live longer.

Why long-distance runners make the best partners

Some archaeologists suggest that it was a time of great rivalry when men were often killed and women had to compete fiercely for partners. It is thought that Palaeolithic hunters chose blondes because they stood out from their rivals and were more likely to be healthy.

Many women who are blonde go darker as they age, so blonde hair is also viewed as an indicator of youth, and sexual vitality.

And, intriguingly, Caucasian blondes usually have slightly higher oestrogen levels than brunettes and are likely to exhibit finer infantile facial features such as a smaller nose, smaller jaw, pointed chin, narrow shoulders, smooth skin and less body hair.

However a recent study which attempted to determine the most beautiful woman in the world picked a brunette. And a 2011 study in the Scandinavian Journal of Psychology, found that brunettes are generally considered more attractive.

A recent study found brown hair was the most attractive for men and women

Body shape

Just as there is an ideal ratio for finger length, it seems that humans are programmed to quickly sum up the bodily measurements of a future lover.

Again these are based on genetic clues which we are unconsciously gleaning from bone ratios.

Men prefer a waist-to-hips ratio of 7:10. Hip width and breast size are important factors in fertility, child birth, and rearing, so there’s definitely an evolutionary connection there.

A BMI (Body Mass Index) of 20.85 has been determined as the most attractive weight for a woman. Scarlett Johansson has previously been voted as having the most attractive female figure.

Women are unconsciously looking for a man who has a waist-to-hip ratio of 9:10 and are attracted to a partner with a big jaw, a broad chin, an imposing brow. The angle between their eyes and mouth, cheekbone prominence, and facial length all play a role as well as does facial hair. Most women prefer heavy stubble to either a beard of clean shaven. However men with full beards are viewed as better fathers.

The perfect man should also have body fat of around 12 per cent which is an important indicator of how well the immune system works.

And the limbal ring — the area where the iris meets the white of the eye — is thought to signal youth and health. In a 2011 study, men and women with a dark limbal ring were perceived as more attractive.

Scarlett Johansson has previously been voted as having the most attractive female figure.

Smell

Scientists are divided about whether humans actually emit pheromones – the chemical signals secreted by animals to help find a mate – but we certainly use smell to detect how genetically compatible a partner might be.

Studies have found that we can literally sniff out our immune system match, the person whose genes complement ours, whic will give us healthier babies.

In fact, the most compatible partner genetically would be the one who is the least like you. In terms of evolutionary biology it is easy to see the benefit of having one partner who is less susceptible to getting colds or flu while another has greater immunity to measles, for example.

When sniffing t-shirts saturated with men’s sweat, women preferred the smells of men with high levels of testosterone, particularly when they were at peak fertility.

However research by Newcastle University has suggested that the Pill could stop women picking up these important genetic clues because it alters hormones which make the body think it is pregnant. While that stops women getting pregnant it also means they would rather be surrounded by close family members, and so are more attracted to people who are genetically similar. And for choosing a partner, that is dreadful.

Pheremone dating now exists to help people find their genetic match

Fitting in

Although it might seem like a good idea to stand out from the crowd when playing the mating game, new research suggests it actually pays to look average.

People with “mathematically average” features advertise a more diverse set of genes and better reproductive health, evolutionary biologists say.

“Basically what our brain does is we go around in our environment, picking up people’s faces and making the average out of these faces we see on a daily basis,” Dr. Kang Lee, psychologist at the University of Toronto.

“And because of that, then, we actually have in our head… a representation of the average of the face. So there’s something we have genetically that’s driving us to prefer to look at something that’s average.”

Ideally, you want the distance between your eyes and mouth to be about 36 percent of the length of your face.

And, the distance between your eyes should be 46 percent of your face’s width.

Natalie Portman has mathematically average features

The voice and mouth

Men prefer women with high, breathy voices as it signifies youth. Women’s voices tend to get lower as they age. A higher pitched voice is also thought to denote small body size.

Female listeners prefer a male voice that signals a large body size with low pitch.

Men are attracted to women who smile, but it’s not true the other way around.

Research found that smiling females were rated as more attractive, whereas men showing happy emotions were rated as less attractive.

Women should smile to look more attractive

E4y.net Info@e4y.net

Why long-distance runners make the best partners

E4y.net

They found that the 10 per cent of men with the most masculine digit ratios were, on average, 24 minutes and 33 seconds faster than the 10 per cent of men with the least masculine digit ratios, suggesting that those who were better runners also had increased fertility.

“The observation that endurance running ability is connected to reproductive potential in men suggests that women in our hunter-gatherer past were able to observe running as a signal for a good breeding partner,” said the study’s lead author Dr Danny Longman.

“It was thought that a better hunter would have got more meat, and had a healthier – and larger – family as a consequence of providing more meat for his family.

“But hunter-gatherers may have used egalitarian systems with equal meat distribution as we see in remaining tribes today. In which case more meat is not a factor, but the ability to get meat would signal underlying traits of athletic endurance, as well as intelligence – to track and outwit prey – and generosity – to contribute to tribal society. All traits you want passed on to your children,” he said.

The most successful prehistoric men were likely to have been persistence hunters who basically stalked their prey until it gave up from sheer exhaustion.

“Humans are hopeless sprinters but are fantastically efficient long-distance runners, comparable to wolves and wild coyotes,” added Dr Longman.

“You can still see examples of persistence hunting in parts of Africa and Mexico today. Hunters will deliberately choose the hottest time of day to hunt, and chase and track an antelope or gnu over 30 to 40 kilometres for four or five hours.

“The animal recovers less and less from its running until it collapses exhausted and is easy to kill.”

The correlation was also found in women, but was much more pronounced in men, suggesting a stronger evolutionary selection in men for running ability.

The 10 per cent of women with the most masculine digit ratios were, on average, 11 minutes and 59 seconds faster than the 10 per cent with the least masculine.

The study was conducted by researchers at the University of Cambridge’s Division of Biological Anthropology and is published in the journal PLOS ONE.

E4y.net Info@e4y.net

Cave crustaceans ‘lose visual brain’

E4y.net
crustacean
Living in total darkness, the animals’ eyes have disappeared over millions of years

A study of blind crustaceans living in deep, dark caves has revealed that evolution is rapidly withering the visual parts of their brain.

The findings catch evolution in the act of making this adjustment – as none of the critters have eyes, but some of them still have stumpy eye-stalks.

Three different species were studied, each representing a different subgroup within the same class of crustaceans.

The research is published in the journal BMC Neuroscience.

The class of “malocostracans” also includes much better-known animals like lobsters, shrimps and wood lice, but this study focussed on three tiny and obscure examples that were only discovered in the 20th Century. It is the first investigation of these mysterious animals’ brains.

“We studied three species. All of them live in caves, and all of them are very rare or hardly accessible,” said lead author Dr Martin Stegner, from the University of Rostock in Germany.

Specifically, his colleagues retrieved the specimens from the coast of Bermuda, from Table Mountain in South Africa, and from Monte Argentario in Italy.

Researcher diving in Bermuda
One of the species was retrieved from caves on the coast of Bermuda

The animals were preserved rather than living, so the team could not observe their tiny brains in action. But by looking at the physical shape of the brain, and making comparisons with what we know about how the brain works in their evolutionary relatives, the researchers were able to assign jobs to the various lobes, lumps and spindly structures they could see under the microscope.

They were also able to infer what the brain of the creatures’ most recent shared ancestor might have looked like.

Evolution in action

“What I’ve done is looked at the structure, and interpreted it in an evolutionary context,” Dr Stegner told the BBC.

Interestingly, while the areas devoted to touch and to smell had remained the same or even expanded in the 200 million years or so since the animals’ ancestry diverged, the bits of the brain devoted to seeing had shrunk.

It is perhaps not a huge surprise that animals living in total darkness might start to shed, over many generations, the parts of their brain devoted to seeing. But this vanishing act had never been confirmed for these species – and the rate of the change was startling, Dr Stegner said.

“The reduction is much more dramatic than for other crustaceans of this group,” he explained.

“It’s a nice example of life conditions changing the neuroanatomy.”

crustacean brain in 3D
The study provides the first anatomical description of these animals’ brains

Furthermore, it is a particularly striking glimpse of nature whittling away unnecessary components, because it has been caught half-way.

Each of these three species comes from its own subgroup, and all the known members of those subgroups are completely blind. But tell-tale signs of their ancestors’ ability to see are still hanging around.

“None of them have eyes, but some of them have rudiments of these eye-stalks,” Dr Stegner said.

In the time it has taken for evolution to get this far in streamlining the crustaceans’ brains, the vast supercontinent Gondwana broke up into today’s land masses. That is one of the reasons Dr Stegner’s three species are distributed the way they are.

By the time those eye-stalk remnants have also disappeared, what our planet will look like is anyone’s guess.

Follow Jonathan on Twitter

crustacean
Another of the crustaceans was found in caves beneath Table Mountain in South Africa
E4y.net Info@e4y.net