Veterinary scientists in Chile have invented a contraceptive vaccine for dogs, which can be used in both males and females, and may provide an inexpensive option to help control the country's growing canine population.
Scientists from the University of Chile Veterinary and Livestock Faculty developed the vaccine from an existing formula used to sterilize pigs, as professor Leonardo Saenz explains.
"It began in Australia more or less in 1989. What we did was to take the concept of immuno-castration which already existed and we developed and improved for use in domestic animals, mainly in dogs, and to create an alternative for pigs, better than what already exists. The previous one was a vaccine by a pharmaceutical laboratory which needs two doses to take effect. In our case, only one dose is needed for the vaccine to take effect," said Saenz.
According to Saenz, the effect of the vaccine is similar to that of a surgical castration without needing the resources and subsequent care such an operation requires.
It is also a reversible measure based on hormonal alterations.
"The vaccine is a recombinant protein generated in Escherichia coli. The protein is carried by inclusive bodies which are purified previously in Escherichia coli, and we create the vaccine using a polymer. Chitosan is used for pigs and this formula permits, or induces the formation of anti-bodies which neutralize the hormone Betatrophin, and these neutralizing anti-bodies prevent reproductive activity. There is no Progesterone or Estrogen in the females and no Testosterone in the males, which blocks reproductive activity and is a form of immunological castration," said Saenz.
Veterinary scientists hope the vaccine will help to control the growing canine population in Chile, where surgical castration is only applied in small numbers. They expect the vaccine could be administered to a group three or four times greater than those that undergo surgery.
A further benefit of the vaccine, according to scientists, is that it has no side effects, unlike other forms of contraception.
"Since it is a vaccine which blocks the production of hormones, it does not function as a contraceptive but rather an immuno-castrator. The difference is that contraceptives prevent animals from going on heat. It will still engage in reproductive activity but it will not be able to fertilize. In this case, there are no hormones so there is no activity, there are no gametes so the animal is sterilized as a result of suppressed hormones. As there is a reduction in the hormonal activity, there are no side effects as is the case with hormonal contraceptives on which they put high quantities of contraceptive or hormones which induce alterations in the uterus and can be related to the appearance of some cancers. In this case that does not happen, we block that activity," said Saenz.
The vaccine has been patented in Chile, Europe and the United States, and is undergoing further tests in controlled conditions. In Chile, the final formula will have to be authorized by the Agricultural and Livestock Service, before it is commercialized.
A number of other dog vaccines are currently under development globally, including one at the California Institute of Technology and another being tested by Oklahoma-based Spay First and the U.S. Department of Agriculture's National Wildlife Research Center.
Over the past half decade, ancient DNA research has revealed some surprising aspects to our evolutionary history during the past 50,000 years.
Perhaps the most startling of these has been the extent to which the ancestors of living people across the planet interbred with other closely related species of human.
But where in the world did these cross-species matings occur? Which archaic species were involved?
Just how much of the human genome comprises DNA from these archaic relatives?
And what impact did interbreeding have on our evolution and general biology as a species?
These are questions are the core of current research into interbreeding as revealed by DNA sequences obtained from fossils in Europe and Asia, as well as from comparisons with the genomes of living people.
In Africa, interbreeding with an archaic species has left genetic signatures in the genomes of some living sub-Saharan populations.
The very well known Neanderthals – for whom we have hundreds of fossils including near complete skeletons – interbred with the founders of living European and East Asian populations.
Yet, East Asians have significantly more Neanderthal genes than Europeans do indicating that their ancestors interbred with this archaic species perhaps more than once, or in an event separate to that involving the ancestors of western Eurasians.
Another species, the mysterious ‘Denisovans,’ is known from the fossil record only by a single tooth, finger bone and toe bone.
Yet their fully sequenced genome shows that they shared their genes with the ancestors of some Southeast Asians, New Guineans and Aboriginal Australians.
These living people also show the genetic signs of interbreeding with Neanderthals, so have inherited DNA from both of these species.
Not only do we all carry the evidence for these interspecies dalliances, in some cases these genes seem to have provided real benefits for us today.
Take for example the finding last year by Emilia Huerta-Sánchez and her team that the ability of populations living today in Tibet to thrive at high altitude is the result of a gene inherited from the mysterious ‘Denisovans.’
The gene in question – EPAS1 – is associated with differences in haemoglobin levels at high altitude underpinning the capacity of the individuals carrying it to pump more oxygen around in their blood.
The Denisovans also seem to have contributed genes that bolstered the immune systems of people in New Guinea and Australia.
Other examples include genes associated with: sugar metabolism; muscle and nervous system function; skin formation and structure; skin, hair and eye colour; and the female reproductive system, especially the formation of ova.
But of course we would expect natural selection to work in both directions given that these mating events were between different species: Homo sapiens x Homo neanderthalensis, Homo sapiens x Denisovans and Homo sapiens x mystery African species.
One particularly interesting example compared the genome of a female Neanderthal with 1,000 contemporary human ones from across the world and found clear evidence for negative selection.
Mapping the DNA of Neanderthals against this large number of human genomes also showed that there were vast ‘deserts’ of Neanderthal ancestry.
One million base pairs compared across the autosomes (i.e. other than the X or Y chromosomes) showed four windows in Europeans and 14 in East Asians where around 0.1% of the DNA was Neanderthal.
The human Y chromosome is also known to be lacking Neanderthal DNA suggesting strong natural selection against hybrid males, who were likely to have been infertile.
Other genes inherited from the Neanderthals seem to have conferred greater risk for a range of diseases such as lupus, biliary cirrhosis, Crohn’s disease, altered optic-disc size, smoking behaviour, IL-18 levels (producing inflammation) and type 2 diabetes.
One of the especially odd things about the evidence for interbreeding with the Denisovans is that the only fossils we have for them were recovered from Denisova Cave in southern Siberia, some 6,000 km northwest of New Guinea.
How can this be given the very high frequency of Denisovan genes in New Guineans and Australians and apparently low level or even absence of Denisovan DNA in the genomes of mainland East Asians?
One study by Skolund and Jakobsson suggested Denisovan DNA may also be found in mainland East Asians, but this has been controversial and difficult to pin down owing to its apparent very low levels.
But if correct, perhaps the mating with the Denisovans happened on mainland East Asia, not so far from Denisova Cave, the genes being carried later to New Guinea and Australia?
A new study of the occurrence of Denisovan DNA in living humans published in the journal Molecular Biology and Evolution has finally confirmed the widespread signal of a low level of Denisovan ancestry across Eastern Eurasian and Native American populations.
Pengfei Qin and Mark Stoneking of the Max Planck Institute for Evolutionary Anthropology examined a set of 600,000 genetic markers in 2,493 individuals from 221 worldwide populations.
They found that for living New Guineans and a single genome sample from the North of Australia around 3.5% of their DNA derives from the Denisovans.
In contrast, in East Asians and Native Americans the amount of Denisovan DNA plummets to a minimal 0.13-0.17% of their genome.
Qin and Stoneking concluded that Denisovan ancestry is therefore strongly associated with New Guinean ancestry.
So, the presence of Denisovan DNA outside of New Guinea – its place of highest occurrence – is probably the result of recent population migrations from New Guinea into Australia, Southeast Asia and mainland East Asia.
In other words, at some time in the past some New Guineans migrated into northern Australia and back to mainland East Asia carrying their Denisovan DNA with them and spreading it around the region.
So far, no archaeological or genetic evidence has been found to support the idea that New Guineans migrated back to Asia well after New Guinea and Australia had been settled.
But, with so many new findings coming from ancient human DNA, and many archaeological models confirmed in the process, we simply can’t afford to dismiss this one.
Once again genetic research is turning long held notions about our evolution on its head: bring it on I say!
Alaska Governor Bill Walker (I) said this week that his state should be allowed to drill more oil to help cover the costs of fighting climate change.
Walker told BBC News that many small coastal towns in Alaska were facing erosion caused by climate change, but the state is facing budget shortfalls caused by a drop in energy prices over the last two years. Alaska, which has no income tax, gets 90 percent of it's revenue by taxing oil and gas production.
In one case, the town of Kivalina lost 10 feet of shoreline in a matter of hours last week. Experts have said that it could cost $100 million to move the town.
"We have villages that are washing away because of the change in the climate," Walker explained. "I don't see anybody putting together contribution funds to help move Kivalina, and so that's our obligation."
"We've got about 12 villages in that same situation," he added. "This isn't something we can put off for 10-20 years... We have to begin this process now - it's an absolute urgency for Alaska."
Environmental activists told the BBC that Walker's idea for drilling more fossil fuels to pay for the impacts of climate change was a "simplistic solution."
"What's going on in villages is certainly of concern to me as an Alaskan but I think the governor knows there's never going to be enough money to move everybody that needs to be moved as climate change continues to advance," Lois Epstein of the Wilderness Society pointed out. "It's really not going to be something that the state is going to take on its own. The federal government is going to help, but we really need some bigger strategies to deal with climate change both as a state and a nation."
Watch the video below from BBC News, broadcast Oct. 12, 2015.
US researchers have used a new gene editing technique to trim away potentially harmful virus genes that have impeded the use of pig organs for transplants in humans.
The study, published in the journal Science, expands on capabilities of the genome editing tool known as CRISPR–Cas9, which works as a type of molecular scissors that can selectively trim away unwanted parts of the genome.
Previous efforts with the technology have only managed to cut away six areas of the genome at one go. In the latest study led by Dr. George Church, a geneticist from Harvard Medical School, researchers simultaneously snipped away genetic material in 62 specific locations in the pig genome.
While Church's team has shown that it is feasible to drastically edit the genome of pigs to remove native pig viruses from pig cells, it has not shown that such organs would be safe to use in people.
Still, Church said in a statement he believes the technology will one day make it possible for pig organs to be used as a substitute for human organs for patients in need of a transplant and for whom there are no suitable donor organs.
Church first revealed his team's feat at an Oct. 5 workshop at the National Academy of Sciences, which is studying the potential risks and ethical concerns of human genome editing.
The technology has ignited an ethical debate after biologists in China reported carrying out the first experiment to alter the DNA of human embryos. British scientists have subsequently asked for permission to edit human embryos.
In the pig experiment, one concern is the potential for genomic rearrangements, in which the editing technique inadvertently makes unwanted changes to the genome. In the Harvard trial, this did not appear to happen.
Church has co-founded a biotechnology company called eGenesis to produce pigs for organ transplants.
Pig-to-human transplants are not novel. Currently, pig heart valves that have been scrubbed and depleted of pig cells are commonly used to repair faulty human heart valves. But whole pig organs, which are functionally similar to human organs, cannot be used because of the potential for transmission of latent retroviruses, which are harmless in pigs, but could cause illness in people.
(Reporting by Julie Steenhuysen; Editing by Andrew Hay)
Paul Douglas, a veteran meteorologist with over 3 decades of experience, revealed to the Minneapolis Star Tribune that he never imagined that the planet would be facing a climate catastrophe when he began his a career.
Douglas, who spent 11 years at both KARE and WCCO, told the Tribune's C.J. that he began to notice in the 1990s that "something had changed."
"I just started connecting the dots, and that led me to climate change. I didn’t wake up and have an epiphany. It had nothing to do with Al Gore. I was tracking Minnesota’s increasingly bizarre weather when I said, 'Something’s up,'" he recalled.
But Douglas said that sharing the science on television was not always easy.
"Look, it’s no secret; local television news is a popularity contest," he explained. "Viewers vote with their remote controls every day, and so if you’re a meteorologist and trying to do the right thing, connect the dots... You know you’re going to piss off 20-30 percent of the audience."
"Talking about climate change probably was not good for my television career. But I happen to believe that some things are more important than ratings. Life isn’t a popularity contest," he noted, adding that conservative meteorologists were more likely to be skeptical of climate change.
"Conservatives, because they fear that tackling climate change will automatically lead to bigger government, it’s easier to push back and deny the science," Douglas admitted. "So yeah, there are meteorologists in this country who are very conservative, who believe there isn’t enough data or the data are inconclusive. I don’t know how much more data you need."
To help get the word out to conservative audiences, Douglas has partnered with a Republican minister to author a book on why evangelicals should care about climate change.
"As I tell people, acknowledging the science, the data, acknowledging that climate change is real doesn’t make you liberal, it makes you literate," Douglas pointed out. "It means you’re scientifically literate. You respond to data and facts and not conspiracy theories and fairy tales."
Watch the video below from the Minneapolis Star Tribune.
The hidden factor behind our sense of fairness is a desire to negotiate our way through life
A four-year-old girl sees three biscuits divided between a stuffed crocodile and a teddy bear. The crocodile gets two; the bear one. “Is that fair?” asks the experimenter. The girl solemnly judges that it is not. “How about now?” asks the experimenter, breaking the bear’s single biscuit in half. The girl cheers up: “Oh yes, now it’s fair. They both have two.” Strangely, children feel very strongly about fairness, even when they scarcely understand it.
Adults care about fairness too – but how much? One way to find out is by using the ultimatum game , created by economist Werner Guth. Jack is given a pile of money and proposes how it should be divided with Jill. Jill can accept Jack’s “ultimatum”, otherwise the deal is off, and neither gets anything.
Suppose Jack and Jill don’t care about fairness, just about accumulating cash. Then Jack can offer Jill as little as he likes and Jill will still accept. After all, a little money is more than no money. But imagine, instead, that Jack and Jill both care only about fairness and that the fairest outcome is equality. Then Jack would offer Jill half the money; and Jill wouldn’t accept otherwise.
What happens when we ask people to play this game for real? It turns out that people value fairness a lot. Anyone offered less than 20-30% of the money is likely to reject it (especially men with high levels of testosterone, it turns out). So people sacrifice hard cash to avoid unfair treatment. And receiving an unfair offers makes us feel sick, almost literally: brain scanning reveals that unfair offers trigger activity in a brain area (the anterior insula) activated by disgusting smells or images. Happily, most offers are pretty equitable; indeed, by far the most common is a 50-50 split.
But children, and adults, also care about a very different sort of (un)fairness, namely cheating – so much so that some evolutionary psychologists suggest we may be “wired” for cheater-detection. Think how many games of snakes and ladders have ended in acrimony when one child “accidentally” miscounts her moves and another child objects. But this sense of fairness isn’t about equality of outcome: games inevitably have winners and losers. Here, fairness is about playing by the rules.
Both types of fairness matter. Fairness-as-equality comes to the fore when we think about divisions of chores, favouritism between children or postcode lotteries in healthcare. Fairness-as-no-cheating is centre stage when we are outraged by professional fouls, drugs in sport, falsifying wills, miscarriages of justice or fraudulent elections.
So which is more important: equality or no-cheating? I think the answer is neither. I suspect that our brains are concerned about something deeper, from which our liking for equality and our hatred of cheating are mere side effects. An unlikely clue comes from considering, of all things, the national lottery. Like other lotteries, it certainly doesn’t make the world more equal: a few people get rich and most people get nothing. Nevertheless, we hope, it is fair – but what does this mean? The fairness-as-no-cheating viewpoint has a ready answer: a lottery is fair if it is conducted according to the “rules”. But which rules? None of us has the faintest idea, I suspect. Suppose that buried in the small print at lottery HQ is a rule that bars people with a particular surname (let’s say, Moriarty). So a Ms Moriarty could buy a ticket each week for years without any chance of success.
How would she react if she found out? Surely with outrage: how dare the organisers let her play, week after week, without mentioning that she couldn’t possibly win! She’d justifiably feel unfairly treated even though the lottery followed the rules to the letter, because these were rules she’d never have agreed to.
To protest against unfairness, then, is to make an accusation of bad faith. From this viewpoint, an even split between the crocodile and the bear seems fair because (normally, at least), it is the only split they would both agree to. But were the girl in our experiment to learn that the crocodile doesn’t like biscuits or that the bear isn’t hungry, I suspect she’d think it perfectly fair for one toy to take the lot. Inequality of biscuits (or anything else) isn’t necessarily unfair, if both parties are happy. And the unfairness of cheating stems from the same source: we’d never accept that someone else can unilaterally violate agreements that we have all signed up to, whether to follow the rules of snakes and ladders or not to take performance-enhancing drugs.
So perhaps the four-year-old’s intuitions about fairness is not the first stirrings of egalitarianism, but the beginnings of an understanding of negotiation. With a sense of fairness, people will have to make us decent offers (or we’ll reject their ultimatums) and stick by the (sensible) rules, or we’ll be on the warpath. So a sense of fairness is crucial to effective negotiation; and negotiation, over toys, treats, bedtimes, chores, money etc, is the fabric of life.
Seattle Seahawks quarterback Russell Wilson and his girlfriend, the singer Ciara, recently announced plans to remain sexually abstinent until marriage.
It was a vow that came as a surprise to many. After all, sexual purity is a commitment that is historically expected of, associated with – even demanded of – women. However, sexual abstinence is not something assumed of men, especially men like Russell Wilson.
Wilson, an accomplished, attractive athlete, embodies contemporary ideals of masculinity, which include style, wealth and, yes, sexual prowess.
So how does a man like Russell Wilson navigate a commitment to abstinence while upholding ideals of masculinity? Wilson’s status as an athlete and heartthrob is likely giving him what sociologist CJ Pascoe calls “jock insurance.” In other words, due to his celebrity status, he can make traditionally nonmasculine choices without having his masculinity questioned.
But what does it mean for a man who isn’t in the limelight, who makes a similar type of commitment to abstinence? And what does it mean for the women they date, and might eventually marry?
I’ve been researching men who pledge sexual abstinence since 2008, work that comes out of a larger scholarly interest in masculinities, religion and sex education.
While men make this commitment with the good intentions for a fulfilling marriage and sex life, my research indicates that the beliefs about sexuality and gender that come hand in hand with these pledges of abstinence do not necessarily make for an easy transition to a married sexual life.
Who’s pledging “purity?”
Comedian Joy Behar recently joked that abstinence is what you do after you’ve been married for a long time. Here, Behar makes two assumptions. One is that sexual activity declines both with age and the time spent in a relationship. This is true.
The second is that abstinence is not something you do before marriage. For the most part, this is true as well: by age 21, 85% of men and 81% of women in the United States have engaged in sexual intercourse.
Still, some in the United States are making “virginity pledges,” and commit to abstinence until marriage. Most of the data that exist on this practice show that those who make the pledges will do so in high school, often by either signing a pledge card or donning a purity ring.
Research on this population tells us a few things: that those who pledge are more likely to be young women, and that – regardless of gender – an abstinence pledge delays the onset of sexual activity by only 18 months. Furthermore, taking a virginity pledge will often encourage other types of sexual behavior.
Virgins in Guyland
But little is known about men who pledge and navigate this commitment to abstinence.
I was curious about how men maintain pledges in light of these statistics, and also balance them with expectations about masculinity. So in 2008, I began researching a support group of 15 men at an Evangelical church in the Southwest. All members were white, in their early to mid-20’s, single or casually dating – and supporting each other in their decisions to remain abstinent until marriage.
The group, called The River, met once a week, where, sitting on couches, eating pizza or talking about video games, they’d eventually gravitate toward the topic that brought them all together in the first place: sex.
On the surface, it would seem impossible for these men to participate in what sociologist Michael Kimmel calls “Guyland” – a developmental and social stage driven by a “guy code” that demands, among other things, sexual conquest and detached intimacy.
Rather, the men of The River approach sex as something sacred, a gift from God meant to be enjoyed in the confines of the marriage bed. At the same time, these men struggle with what they describe as the “beastly elements” – or temptations – of sexuality. And it is precisely because of these so-called beastly elements that these men find each other in the same space every week.
The men of The River grappled with pornography use, masturbation, lust and same-sex desire, all of which can potentially derail these men from their pledge.
It raises an interesting dilemma: to these men, sex is both sacred and beastly. Yet the way they navigate this seeming contradiction actually allows them to exert their masculinity in line with the demands of Guyland.
Group members had an elaborate network of accountability partners to help them resist temptations. For example, one had an accountability partner who viewed his weekly online browsing history to make sure he wasn’t looking at pornography. Another accountability partner texted him each night to make sure that he and his girlfriend were “behaving.”
While these behaviors may seem unusual, they work in ways that allow men to actually assert their masculinity. Through what sociologist Amy Wilkins calls “collective performances of temptation,” these men are able to discuss just how difficult it is to refrain from the beastly urges; in this way, they reinforce the norm that they are highly sexual men, even in the absence of sexual activity.
The River, as a support group, works largely in the same way. These men are able to confirm their sexual desires in a homosocial space – similar to Kimmel’s research in Guyland – from which Kimmel notes that the “actual experience of sex pales in comparison to the experience of talking about sex.”
A ‘sacred gift’ – with mixed returns
The men of The River believed that the time and work required to maintain these pledges would pay off in the form of a happy and healthy marriage.
Ciara, in discussing her commitment to abstinence with Russell Wilson, similarly added that she believes such a promise is important for creating a foundation of love and friendship. She stated that, “if we have that [base] that strong, we can conquer anything with our love.”
So what happened once after the men of The River got married? In 2011, I followed up with them.
All but one had gotten married. But while the transition to married life brought promises of enjoying their “sacred gift from God,” this gift was fraught.
Respondents reported that they still struggled with the beastly elements of sexuality. They also had the added concern of extramarital affairs. Furthermore – and perhaps most importantly – men no longer had the support to work through these temptations.
There were two reasons behind this development.
First, respondents had been told, since they were young, that women were nonsexual. At the same time, these men had also been taught that their wives would be available for their pleasure.
It’s a double standard that’s in line with longstanding cultural ideals of the relationship between femininity and purity. But it’s a contradiction that leaves men unwilling to open up to the very women they’re having sex with.
These married men and women were not talking to each other about sex. Rather than freely discussing sex or temptation with their wives (as they had done with their accountability partners), the men simply tried to suppress temptation by imagining the devastation any sexual deviations might cause their wives.
Second, these men could no longer reach out to their support networks due to their own ideals of masculinity. They had been promised a sacred gift: a sexually active, happy marriage. Yet many weren’t fully satisfied, as evidenced by the continued tension between the sacred and beastly. However, to open up about these continued struggles would be to admit failure as masculine, Christian man.
In the end, the research indicates that a pledge of sexual abstinence works to uphold an ideal of masculinity that disadvantages both men and women.
After 25 years of being told that sex is something dangerous that needs to be controlled, the transition to married (and sexual) life is difficult, at best, while leaving men without the support they need. Women, meanwhile, are often left out of the conversation entirely.
So when we urge abstinence in place of healthy conversations about sex and sexuality, we may be undermining the relationships that are the driving goal of these commitments in the first place.
Pluto has blue skies and patches of frozen water, according to the latest data out Thursday fromNASA's unmanned New Horizons probe, which made a historic flyby of the dwarf planet in July.
Never before has Pluto -- a resident of the distant Kuiper Belt, a frigid region of the solar system beyond Neptune that is home to many comets and asteroids -- been observed in such detail.
"Who would have expected a blue sky in the Kuiper Belt? It's gorgeous," said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.
Along with the announcement, NASA released an image showing a blue layer of haze around Pluto, taken by the New Horizons spacecraft's camera.
Blue skies are seen on Earth because of the scattering of sunlight by very small particles of nitrogen.
"On Pluto they appear to be larger -- but still relatively small -- soot-like particles we call tholins," said science team researcher Carly Howett, also of SwRI.
NASA said the "second significant finding" from New Horizons' latest trove of data is that there are numerous small, exposed regions of frozen water on Pluto.
Using a tool called a spectral composition mapper on New Horizons, scientists have been able to map the signatures of water ice on various parts of the planet's surface.
"Large expanses of Pluto don't show exposed water ice," said science team member Jason Cook of SwRI. "Because it's apparently masked by other, more volatile ices across most of the planet."
"Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into."
The areas that seem to contain the most water ice also appear bright red in recent color images of Pluto.
"I'm surprised that this water ice is so red," said Silvia Protopapa, a science team member from the University of Maryland, College Park.
"We don't yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface."
Scientists have previously reported seeing flowing nitrogen ice glaciers on the surface of Pluto.
On July 14, New Horizons, a nuclear-powered spacecraft about the size of a baby grand piano, became the first spaceship to pass by Pluto. It will continue to send data back to Earth until late next year.
NASA says the spacecraft is pressing on and is in good working order some 3.1 billion miles (five billion kilometers) from Earth.
U.S. researchers on Thursday said they had found a way to predict male sexual orientation based on molecular markers that control DNA function, but genetics experts warned that the research has important limitations and will not provide definitive answers to a potential biological basis for sexual preference.
Findings from the study, which has yet to be published or reviewed in detail by other scientists, were presented at a meeting of the American Society of Human Genetics in Baltimore.
It followed 37 pairs of identical male twins in which one was homosexual and one heterosexual, and 10 sets of twins in which both males were homosexual. The study found that the presence of specific epigenetic marks in nine areas of the human genome could predict homosexual preference with up to 70 percent accuracy.
The epigenome is sometimes described as molecular "switches" that can turn on or silence individual genes in DNA. Scientists believe epigenetic differences can be influenced by environmental and lifestyle factors, from exposure to chemicals to parental nurturing.
"To our knowledge, this is the first example of a predictive model for sexual orientation based on molecular markers," Tuck Ngun, lead researcher on the study from the David Geffen School of Medicine of the University of California, Los Angeles, said in a statement.
Genetics experts who critiqued the findings said it was premature to draw any conclusions on the predictive powers of epigenetic markers.
"The question as to whether that prediction is going to be useful outside of the small number of twins in the study is really unclear," said Dr. Christopher Gregg, a genetics professor at the University of Utah.
Others noted the small size of the population studied and stressed that such findings often fall apart when applied to larger groups of people.
"One thing you can clearly see is that the sample size is too small. They don't have enough power to make that claim," said Dr. Peng Jin, professor of human genetics from Emory University in Atlanta, who attended the meeting in Baltimore.
"What they are seeing may be certain correlations, but I don't think they have what they claim, which is a predicting model," he added. "It's definitely an interesting observation, but ... I don't want the general audience to misinterpret whatever they are presenting," Jin said.
Gregg said he was impressed by the UCLA team's "state-of-the-art" methodology, but said much larger studies must be undertaken to reach any conclusions.
"Just because there is something different doesn't mean that's what's causing people to behave one way versus the other," he said.
(Reporting by Bill Berkrot; Editing by Dan Grebler)
DNA extracted from the skull of a man buried 4,500 years ago in an Ethiopian cave is providing new clarity on the ancestry of modern Africans as well as shedding light on an influx of people from the ancient Middle East into the Horn of Africa.
The man, dubbed "Mota," became the first ancient African whose genome has been sequenced, revealing his complete genetic blueprint, scientists said on Thursday. Until now, genome sequencing efforts on ancient people have focused on remains from cooler, drier climes that tend to better preserve DNA.
The cave, sitting 6,440 feet (1,963 meters) above sea level in southwestern Ethiopia's Gamo highlands, was discovered in 2011, University of Cambridge geneticist Andrea Manica said.
In it was the skeleton of an adult male who may have been bound at the time of burial, with stone tools also found in the grave. "Mota" lived in a hunter-gatherer culture, anthropologist Matthew Curtis of UCLA and Ventura College said.
DNA was extracted from the petrous bone, a dense region of the skull excellent for preserving DNA in ancient samples, Trinity College Dublin geneticist Eppie Jones said.
The man had dark skin, brown eyes, and genetic adaptations for living at high altitudes, Jones said.
"Mota is genetically very similar to current inhabitants of the Ethiopian highlands and eastern Africa," Manica said.
He had no trace of Eurasian ancestry, enabling the researchers to use his genome to better understand the Eurasian genetic component now seen in modern Africans. They used his genome to determine there was a large migration of western Eurasians into Africa around 3,500 to 4,000 years ago, University of Cambridge geneticist Marcos Gallego Llorente said.
This migration from the ancient Near East and Fertile Crescent, roughly corresponding to modern Iraq, Turkey, Iran and Syria, reshaped the African continent's genetic makeup.
By comparing the ancient genome to DNA from modern Africans, the researchers showed today's East Africans have up to 45 percent Eurasian ancestry from this ancient migration and that populations in all corners of Africa have at least 6 percent of their genome arising from the Eurasian migration.
These Eurasians were closely related to the people who introduced agriculture to Europe 8,000 years ago, Gallego Llorente said. There already was agriculture in the Horn of Africa when they arrived, but they introduced new crops and animals to the region.
The research was published in the journal Science.
(Reporting by Will Dunham; Editing by Sandra Maler)
Despite their big size, elephants rarely get cancer, and scientists said Thursday they have discovered the secret to the creatures' special protection. It's in the genes.
Elephants have 38 additional modified copies of a gene that encodes p53, a compound that suppresses tumor formation.
Humans, on the other hand, have only two, according to the study in the Journal of the American Medical Association (JAMA).
This means that as elephants evolved, their bodies made many extra copies of a gene that prevents tumors from forming.
Elephants have been considered an enigma for years because they have far more cells than people, which would presumably place them at higher risk of cancer over their lifespans which can last 50-70 years.
And yet, the analysis of a large database of elephant deaths showed that less than five percent of elephants die of cancer, compared to 11 to 25 percent in people.
"By all logical reasoning, elephants should be developing a tremendous amount of cancer, and in fact, should be extinct by now due to such a high risk for cancer," said co-senior author Joshua Schiffman, pediatric oncologist at Huntsman Cancer Institute, University of Utah School of Medicine.
"We think that making more p53 is nature's way of keeping this species alive."
Elephants also come naturally equipped with a more aggressive internal mechanism for killing damaged cells that are at risk for becoming cancerous, researchers said.
"In isolated elephant cells, this activity is doubled compared to healthy human cells," said the study, which was co-authored by experts from Arizona State University and the Ringling Bros. Center for Elephant Conservation.
Researchers hope that their findings could one day lead to new cancer-fighting therapies in people.
But that day could be far off, according to Mel Greaves, director of the Centre for Evolution and Cancer at The Institute of Cancer Research, London.
"The new research provides a plausible answer to one of the most celebrated riddles in evolutionary biology ?- why some big animals with lots of cells still manage to have quite low rates of cancer," said Greaves, who was not involved in the study.
"It is not immediately clear what lessons there are from this elephant tale for risk of cancer in humans. The main impact of this remarkable story is to bring into focus the question of why we are so uniquely predisposed to cancer for our size and lifespan ?- and what we can do to change this."
The discovery that won the latest Nobel Prize for Medicine wouldn’t have been much of a revelation to doctors in ancient China. Pharmaceutical chemist Tu Youyou established that the compound artemisinin could treat malaria in the early 1970s. But the plant the chemical comes from, Artemisia annua L. (sweet wormwood), was used to treat fevers perhaps caused by malaria as early as the third or fourth century CE.
Tu discovered the properties of artemisinin (qinghaosu in Chinese) after reading traditional Chinese texts that dated to this era listing medicinal herb preparations. The route to the discovery and its dissemination was not easy due to both the difficulties of trawling through and testing hundreds of plant samples and the political climate in China in the 70s. Fortunately, persistence paid off and artemisinin is now a key antimalarial drug.
While this story might be unusual in modern medicine, artemisinin is far from the only compound used today that was initially derived from plants. For example, another malaria treatment, quinine, is derived from the bark of South American rainforest tree Cinchona officinalis L. The painkiller morphine comes from the opium poppy Papaver somniferum L. And the poison strychnine comes from the Strychnos nux-vomica L. tree. Those plants had been in use for centuries, even millennia, before chemists isolated their most active constituents.
So can we hope to find new remedies by studying ancient medical texts, as Tu did so successfully? The answer to that question is complex and unfortunately cannot be an unmitigated, resounding “yes”. Ancient pharmacological texts, whether they are written in Chinese, Arabic or Greek (or any other ancient language) are not easy to navigate for several reasons.
Ancient cookery books
These pharmacological texts normally present themselves as a series of recipes without much information as to whether they were used or not. Think of your favourite cookery book: you probably do not make all the recipes in it and if you do not annotate it then nobody would know which ones you used and how much you enjoyed them (or not). We rarely find annotations on ancient pharmacological texts.
It is often difficult to know exactly which plants are listed in an ancient recipe. Nowadays, the international Linnaean plant nomenclature is used worldwide to name plants, with each given a genus and a species name, as well as an author’s name. For instance, in “Artemisia annua L.”, “Artemisia” refers to the genus, “annua” refers to the species, and “L” refers to Linnaeus, the famous Swedish botanist.
But before the Linnaean system became widely accepted, plant nomenclature was extremely unstable and various local names could be used to refer to the same plant. This means it is not always possible to know for sure which plants are referenced in ancient texts. If we cannot translate ancient recipes accurately, how can we evaluate their efficacy?
Definitions of diseases are culturally bound. This means that each culture will define its diseases in a different way. For instance, the Greeks and the Romans considered fever to be a disease, whereas we would think of it as one symptom of a disease.
In Greek and Roman texts, there are many descriptions of “intermittent fevers”, fevers that reoccur every few days. Now, intermittent fevers are a symptom of malaria, but they are also symptomatic of other diseases. Should scientists test all ancient Greek and Roman remedies for “intermittent fevers” in their search for new antimalarial drugs?
Holistic medicine
Perhaps most importantly, historians of medicine believe that every medical system should be considered in its entirety. That means, from a historian’s point of view, it is problematic only to focus on aspects of ancient medicine that are successful by modern standards and reject the rest as uninteresting.
While there are many ancient medicines that are effective by modern standards, many are not or are frankly dangerous. For instance, very few of us would think it wise to purge ourselves of a disease by overdosing on hellebore, as the Greeks often did.
With all these provisos in mind, I would still argue that there is much potential for discoveries of new drugs in ancient medical texts. This will require collaborations between pharmacologists, historians and ethno-pharmacologists (who study traditional medicine use by different ethnic groups).
Such collaboration will prove challenging as everyone will feel they are speaking a different language. But the wonderful example of Tu Youyou should remind us that the rewards can be high, especially when they lead to advances in the fight against such widespread diseases.
Thousands expected to take part in ‘red line’ blockades of Paris climate summit, after two weeks of colourful protests that have been dubbed ‘the Climate Games’
Thousands of climate change campaigners have promised to blockade a major UN climate summit in Paris with what they say will be non-violent direct action on a scale Europe has not seen before.
Grassroots groups from 350.org to Attac France are throwing their weight behind the “Climate Games” event for the landmark climate conference in December. The protests will involve 10 blockades, themed around “red lines” which they fear negotiators for the nearly 200 countries inside the summit may cross.
“The redlines idea strikes just the right balance between ‘shut it down’ and ‘do your job’,” the author and campaigner Naomi Klein told the Guardian. “I also think that it is strong enough to grab the narrative, which will be critical if governments try to sell a bad deal as a success.”
On the last day of the summit - 11 or 12 December - thousands of people are expected to converge around the Le Brouget summit site with inflatable red lines, said John Jordan , an artist and prominent activist in the laboratory of insurrectionary imagination .
“The idea is not to lock the delegates in but to have acts of civil disobedience that block the streets and infrastructure, if they cross red lines that are minimal necessities for a liveable planet.”
Protesters can choose the red line they want to join, whether it is equitable climate finance for poorer countries, or meaningful emissions reductions. At the blockades, forums will debate a new wave of actions in 2016 aimed at keeping fossil fuels locked underground.
“It is going to be the largest mass civil disobedience climate justice action that we have ever seen in Europe,” said Prayal Parekh, a campaigner with 350.org. “We’re sensing a lot of excitement and appetite. It’s going to be colourful.”
Juliette Rousseau, a spokeswoman for Coalition Climat 21 added: “It is the first time in France that we have had such a broad coalition - over 130 members - backing such a diversity of actions and tactics, from demonstration to disobedient actions.”
A potentially huge march on 29 November will kick off the protests as world leaders arrive at the summit. The demo is an attempt to emulate last year’s People’s Climate March in New York city , which drew 300,000 people onto the streets. Major environmental groups such as Greenpeace and WWF are jointly organising it with online campaigners Avaaz, trades unions and faith groups.
After that, the so-called Climate Games will begin. Activists can anonymously register for teams online and, over the two-week period, download targets for non-violent direct actions – or upload maps to enable others to join in.
As the summit continues, the games are intended to escalate with a mixture of protests, street art, attention-grabbing actions and online hacks .
“There have definitely been conversations with Anonymous,” one activist source said. I know that [the Climate Games activists] have been chatting with them but I don’t know if they’ve made any concrete plans yet.”
In a taste of things to come, Attac France last week began a process of “ requisitioning” 196 chairs from global banks (one for each of the countries at the climate talks) to draw attention to the potential climate funds that could be raised from a clampdown on tax evasion.
The Climate Games’ internal guidelines, seen by the Guardian, say it will oppose any attempts to “use our mobilisation for reactionary, nationalist or violent goals.”
Parekh said that non-violent action was vital. “I’m from India and civil disobedience is how my country got its independence,” she said. “Now we’re at the cusp of a chance to shift away from fossil fuels and make our societies more equitable and I want to seize the opportunity for a better future. I don’t want to have to read about the hottest summer ever or Pacific islands disappearing anymore.”
