The Null Device

Posts matching tags 'biology'

2012/12/3

A recent study, ranking different breeds of cats in friendliness (to humans), has found that pedigree cats are friendlier than moggies. The study, from the National Veterinary School of Alfort in Paris, found that the friendliest breed being the sphynx, a rare hairless variety.

The researchers believed the sphynx’s affectionate nature could be due to its reliance on humans to keep warm. The study also suggested that the greater affability of pedigrees came about because breeders tended to leave the kittens with their mothers for longer, during a crucial period in their development, when they are becoming used to humans. It could also be the result of selecting more friendly cats for breeding.
The selection hypothesis sounds plausible; by comparison, Russian researchers managed to domesticate foxes in a mere 35 generations, and also managed to breed a vicious, highly aggressive variety by selecting for the exactly opposite traits. Presumably pedigree cats have been bred for long enough to significantly alter their psychological make-up compared to free-range varieties.
The sphynx scored an average of 22.83, compared with 18.93 for the domestic short-haired. Because the numbers of other breeds in the survey were generally small, they were grouped together to score an average for pedigrees of 20.40.
I wonder whether a study of friendliness in sphynx cats in warm and cold climates would yield any significant differences.

biology cats evolution science 0

2011/9/23

In recent medical/biotechnological breakthroughs: players in an online game simulating protein folding have successfully determined the 3-dimensional structure of a protein in a simian virus related to HIV, a hard problem which is not feasible to do with brute-force computation:

Teams of players collaborate to tweak a molecule’s model by folding it up in different ways. The result looks somewhat tangled, but each one is scored on criteria such as how tightly folded it is and whether the fold avoids atoms clashing. The structure with the highest score wins. Anyone can play and most of the gamers have little or no background in biochemistry.
“People have spatial reasoning skills, something computers are not yet good at. Games provide a framework for bringing together the strengths of computers and humans. The results in this week’s paper show that gaming, science and computation can be combined to make advances that were not possible before.”
Meanwhile, an experiment in using genetically modified HIV to destroy cancer cells has worked spectacularly well, with an experimental patient apparently having been cured of leukaemia, and remaining in full remission one year later:
At first, nothing happened. But after 10 days, hell broke loose in his hospital room. He began shaking with chills. His temperature shot up. His blood pressure shot down. He became so ill that doctors moved him into intensive care and warned that he might die. His family gathered at the hospital, fearing the worst. A few weeks later, the fevers were gone. And so was the leukemia.
But scientists say the treatment that helped Mr. Ludwig ... may signify a turning point in the long struggle to develop effective gene therapies against cancer. And not just for leukemia patients: other cancers may also be vulnerable to this novel approach — which employs a disabled form of H.I.V.-1, the virus that causes AIDS, to carry cancer-fighting genes into the patients’ T-cells. In essence, the team is using gene therapy to accomplish something that researchers have hoped to do for decades: train a person’s own immune system to kill cancer cells.
Meanwhile, HIV research has yielded an unexpected boon, in the form of cats that glow in the dark.

biology biotech cancer cats gamification green fluorescent protein hiv science 1

2011/3/24

Scientists in China have found that mice bred to not be receptive to serotonin have no sexual preferences for either sex:

When presented with a choice of partners, they showed no overall preference for either males or females. When just a male was introduced into the cage, the modified males were far more likely to mount the male and emit a "mating call" normally given off when encountering females than unmodified males were.
However, a preference for females could be "restored" by injecting serotonin into the brain.
The researchers have cautioned against drawing conclusions about human sexuality from the result.

The lazy takeaway from this, as seen in news sites, is that serotonin affects sexual orientation, with the suggestion that low serotonin might be the secret to the inexplicable condition known as homosexuality. I'm wondering whether a more plausible conclusion is that, with sexual selection being about competition amongst fit individuals, a prerequisite for having an active sexual preference is passing an internal test of subjective fitness, i.e., being aware that one has sufficiently high status to be picky. In other words, mice without functioning serotonin receptors perceive themselves as losers who will take anything that's warm and regard it, being more than they're entitled to, as a win.

biology neurochemistry neurology psychology sex 4

2010/8/5

The Rap Guide To Human Nature is a hip-hop album about evolutionary psychology by a Canadian "rap troubador" named Baba Brinkman. It's not a joke: the beats are sharp, and Brinkman rhymes with the speed and dexterity of an accomplished rapper, deftly laying out the theories and controversies of evolutionary psychology, from kin selection to the biological roots of religious and political belief, twin studies to alternative models of human nature, and of course to areas such as sexual competition and social status where hip-hop culture and evolutionary psychology intersect. Note that, as expected from rap, the lyrics are probably not suitable for children.

(via Mind Hacks) awesome biology culture evolutionary psychology hip-hop psychology religion science sex 1

2010/7/26

Evolutionary psychologist Daniel Nettle claims that a lot of the social problems associated with socioeconomic deprivation are actually evolutionarily adaptive strategies for maximising opportunities when faced with uncertain prospects. To wit: risk-taking behaviour such as gambling and crime make sense when, ordinarily, individuals' prospects look bleak, unhealthy diets make sense when there isn't much of a future to plan for (junk food, after all, is a far more economical source of energy in the short term than eating healthily), and, as for teenage pregnancy, that's what's known as a fast reproductive strategy (i.e., have as many offspring as quickly as possible and hope that some do OK rather than putting all your proverbial eggs in one basket):

At a meeting last year, Sarah Johns at the University of Kent in Canterbury, UK, reported that in her study of young women from a range of socioeconomic backgrounds in Gloucestershire, UK, those who perceived their environment as risky or dangerous, and those that thought they might die at a relatively young age, were more likely to become mothers while they were in their teens. "If your dad died of a heart attack at 45, your 40-year-old mum has got chronic diabetes and you've had one boyfriend who has been stabbed, you know you've got to get on with it," she says.
Fathers in deprived neighbourhoods are more likely to be absent, which could be because they are following "fast" strategies of their own. These include risky activities designed to increase their wealth, prestige and dominance, allowing them to compete more successfully with other men for sexual opportunities. These needn't necessarily be antisocial, but often they are. "I'm thinking about crime here, I'm thinking about gambling," says Nettle, and other risky or violent behaviours that we know are typical of men in rough environments. A fast strategy also means a father is less likely to stick with one woman for the long term, reducing his involvement with his children.
Once you are in a situation where the expected healthy lifetime is short whatever you do, then there is less incentive to look after yourself. Investing a lot in your health in a bad environment is like spending a fortune on maintaining a car in a place where most cars get stolen anyway, says Nettle. It makes more sense to live in the moment and put your energies into reproduction now.
These fast strategies, unfortunately, form a feedback loop: children brought up with minimal investment by fast-strategy parents are more likely to perceive their prospects as bleak and engage in similar strategies (studies have shown daughters of absentee fathers being more likely to become pregnant in their teens, for example). Meanwhile, junk-food diets stunt cognitive development, further sabotaging attempts to break the cycle.

The upshot of all this is that, if Nettle's theory holds, campaigns against unhealthy or antisocial behaviours are merely treating the symptoms, and real improvements can only come from addressing the underlying causes of such insecurity, i.e., poverty and uncertainty. Of course, actually doing so is a lot more expensive and could prove electorally unpopular, especially when opportunistic politicians are willing to promise cheaper solutions and voters are eager to believe that they will work.

biology crime evolutionary psychology inequality junk food poverty society 2

2010/7/6

New research suggests that differences between average national IQs may be due to the prevalence of parasites. One theory posits that children from countries with high incidences of parasites devote energy to fighting them off which would otherwise be spent on brain development.

When the researchers analyzed each factor independently, they found that infectious disease burden was more closely correlated to average IQ than the other variables. "Parasites alone account for 67% of the worldwide variation in intelligence," Eppig says.
Meanwhile, a correlation has been found between incidence of the parasite Toxoplasma gondii (i.e., the crazy-cat-lady parasite) and a nation's success in football, though the cause of the correlation is still unknown:
Rank the top 25 FIFA team countries by Toxo rate and you get, in order from the top: Brazil (67 percent), Argentina (52 percent), France (45 percent), Spain (44 percent), and Germany (43 percent). Collectively, these are the teams responsible for eight of the last 10 World Cup overall winners.
Now, what does the Toxo parasite do that could possibly relate to soccer performance? Not much is known about its impact on the human brain, but there are clues. We know that infection increases testosterone in male brains, making them more likely to get into car accidents, more attractive to females, and more prone to being jealous, dogmatic, and dismissive of authority. Evidence even suggests that motorcyclists are more likely to have Toxo. Something like a James Dean effect. Generally, males with Toxo are more aggressive and less inhibited. Keep in mind that FIFA, in line with most sporting organizations in the world, bans testosterone supplements of any kind. But they do not ban Toxo, and if Toxo increases testosterone levels, we may be dealing with a form of inadvertent, cultural doping.

(via MeFi, Boing Boing) biology culture football intelligence parasites stupidity 1

2010/5/21

Craig Venter (of Human Genome Project fame) has succeeded in creating synthetic life; i.e., of creating a living cell whose genome was entirely written from scratch in the laboratory. Venter's first commercialisation of the discovery will be a deal with ExxonMobil to create algae which absorb carbon dioxide and create hydrocarbon fuel. Beyond that, the possibilities are vast; from the mundane (cancer cures, new terrorist bioweapons, weird new designer drugs for mutant freak subcultures out of a Warren Ellis or John Shirley story) on to the horizon of the unimaginable.

And Quinn Norton says that we've just lost the War On Drugs, but not as badly as the drug lords, whose business model looks as doomed as the RIAA's:

You know what’s a lot easier than all the high minded business about environment, or life extension, or even the scary doomsday 12 Monkeys scenarios? Growing simpler molecule drugs. I don’t mean like aspirin, I mean like heroin and cocaine, THC and hallucinogens. They already grow in plants thoroughly studied, and people are motivated and not at all risk averse about getting those sequences somewhere they can use them. Cooking meth is hard and dangerous science compared to the ability to get a starter of a minimal cell that poops heroin and feeding it growth medium in your closet. We may have lost the drug war, but not as badly as the drug lords have.
It’s still hard to grow drugs in medium. But the whole point of this project is to make it easier. Who will be motivated to put in the work to make it happen? Especially if it’s so bad for organized crime? Drug addicts, frankly. You think they look like street junkies with DTs, but a fair number look like scientists, because they are. Drugs will finally be p2p, and governments and drug lords alike will find out what it’s like to be media companies and counterfeiters in a world of lossless copying and 100Mb pipes. Junkies will be victims of their success, and if we don’t get serious about treating addiction instead of trying to fight chemicals, it’s going to look a lot more bloody and horrid than the RIAA’s lawsuit factory. This is just one vision of what this kind of disruption looks like when people get a hold of it.

biology biotech genetics gibson's law science the war on drugs 1

2010/1/25

A Russian ecologist has found that the fierce pressure of living in a hostile urban environment is causing Moscow's stray dogs to evolve increased intelligence, including abilities to negotiate the city's subway system:

Poyarkov has studied the dogs, which number about 35,000, for the last 30 years. Over that time, he observed the stray dog population lose the spotted coats, wagging tails, and friendliness that separate dogs from wolves, while at the same time evolving social structures and behaviors optimized to four ecological niches occupied by what Poyarkov calls guard dogs, scavengers, wild dogs, and beggars.
But beggar dogs have evolved the most specialized behavior. Relying on scraps of food from commuters, the beggar dogs can not only recognize which humans are most likely to give them something to eat, but have evolved to ride the subway. Using scents, and the ability to recognize the train conductor's names for different stops, they incorporate many stations into their territories.
Additionally, Poyarkov says the pack structure of the beggars reflects a reliance on brain over brawn for survival. In the beggar packs, the smartest dog, not the most physically dominant, occupies the alpha male position.
I wonder whether similar evolutions of animal intelligence, driven by the conditions of living in cities, have occurred in other cities; there have been anecdotal reports of pigeons deliberately catching the Tube in London, with speculation that they commute in to the tourist-rich city to feed before returning to the suburbs. (As such, one could probably refer to them as passenger pigeons.) Not to mention two instances of cats deliberately catching buses (both in England).

(via Infrastructurist) animals biology cats dogs evolution london moscow public transport russia 2

2009/12/1

Scientists in the Netherlands have come one step closer to creating vat-grown meat. The team at Eindhoven University have grown muscle tissue from cells extracted from a pig. They still need to find a way of exercising the tissue to turn it into something resembling meat; at present, it is described as "a soggy form of pork", though they say that this development could lead to sausages in as little as five years.

It is hoped that, when it arrives, vat-grown meat will be vastly more environmentally efficient, requiring fewer resources to grow, not to mention being free of animal suffering. The current process is not vegetarian, though, using animal blood products in the growth medium.

On a tangent: earlier this year, scientists mapped the cow genome, and discovered that the genes involved in making cattle docile are in regions which, in humans, are involved in mental retardation.

(via MeFi) biology ethics food genetics meat science 2

2009/5/27

A New York Times article from 10 years ago reveals that, over 40 years, Soviet scientists managed to create a domesticated variety of silver fox through selective breeding:

In a long-term experiment at a Siberian fur farm, geneticists have created this new version of Vulpes vulpes, the silver fox, by allowing only the friendliest animals from each generation to breed. Having selected only the most ''tamable'' of some 45,000 foxes over 35 generations, the scientists have compressed into a mere 40 years an evolutionary process that took thousands of years to transform ancestral wolves into domestic dogs.
The original purpose of the breeding was to create a friendly breed less likely than wild animals to fight when put to death. But in time, geneticists saw that far-reaching changes they observed in the foxes' physical and neurological makeup merited scientific study. The scientists apparently underwent some changes, too. Close bonds developed between the tame foxes and their human wardens, and the staff at the fur farm is trying to find ways of saving the animals from slaughter.
("Friendly" there seems like a euphemism; "gullible" or "stupid" might be more appropriate.)

The results of the experiment were domestic foxes ''as devoted as dogs but as independent as cats, capable of forming deep-rooted pair bonds with human beings'', which also developed a variety of physical differences from their wild ancestors:

The normal pattern of coat color that evolved in wild foxes as camouflage changed markedly in the genetically tamed fox population, with irregular piebald splotches of white fur appearing in some animals. The tame foxes sometimes developed floppy ears in place of the straight ones of wild foxes. The domesticated foxes generally had shorter legs and tails than ordinary foxes, and often had curly tails instead of straight, horizontal tails.
Moreover, the faces of adult tame foxes came to look more juvenile than the faces of wild adults, and many of the experimental animals developed dog-like features, Dr. Trut reported. Although no selective pressures relating to size or shape were used in breeding the animals, the skulls of tamable foxes tended to be narrower with shorter snouts than those of wild foxes.
Even more interesting were neurochemical differences: the tame foxes' adrenal glands, which produce adrenaline to prepare animals for fight or flight, had declined in hormone-producing ability with each generation, while after only 12 generations, their brains contained significantly higher levels of serotonin.

Unfortunately, it appears that the project ran out of money some time in the late 1990s, and most of the foxes were destroyed or sold off to fur breeders in Scandinavia. The institute had plans to sell pups as house pets, though it is not clear whether anything came of those.

(Via a comment on this MeFi thread about the history of domestic cats.)

biology foxes genetics russia science ussr 5

2008/11/12

A biologist and a sociologist have put forward a new theory of brain development and mental disorders. Crespi and Badcock's theory posits a spectrum running between autism and related social dysfunctions on one side and schizophrenia, depression and bipolar disorder on the other, with the struggle between maternal and paternal genes in the womb determining where the child's neurology will fall on this axis:

Dr. Crespi and Dr. Badcock propose that an evolutionary tug of war between genes from the father’s sperm and the mother’s egg can, in effect, tip brain development in one of two ways. A strong bias toward the father pushes a developing brain along the autistic spectrum, toward a fascination with objects, patterns, mechanical systems, at the expense of social development. A bias toward the mother moves the growing brain along what the researchers call the psychotic spectrum, toward hypersensitivity to mood, their own and others’. This, according to the theory, increases a child’s risk of developing schizophrenia later on, as well as mood problems like bipolar disorder and depression.
It was Dr. Badcock who noticed that some problems associated with autism, like a failure to meet another’s gaze, are direct contrasts to those found in people with schizophrenia, who often believe they are being watched. Where children with autism appear blind to others’ thinking and intentions, people with schizophrenia see intention and meaning everywhere, in their delusions. The idea expands on the “extreme male brain” theory of autism proposed by Dr. Simon Baron-Cohen of Cambridge.
“Think of the grandiosity in schizophrenia, how some people think that they are Jesus, or Napoleon, or omnipotent,” Dr. Crespi said, “and then contrast this with the underdeveloped sense of self in autism. Autistic kids often talk about themselves in the third person.”

(via MeFi) autism biology genetics mental health mental illness neurology psychology schizophrenia science 0

2008/3/4

Estrogen-like substances in toxic waste turn male fish female; now, it turns out, they turn male songbirds into super-smooth lotharios, capable of singing the songs that get them all the chicks, like a wave of avian Smoove Bs:

Accordingly, the polluted male starlings sang songs of exceptional length and complexity -- a birdsign of reproductive fitness. Female starlings preferred their songs to those of unexposed males, suggesting that the polluted birds could have a reproductive advantage, eventually spreading their genes through starling populations.
(Today's word of the day is "birdsign". If you're an indie-folk songwriter, make a note of that one.)

(via Boing Boing) better living through chemistry biology birds environment music pollution sex toxic waste unintended consequences 0

2008/1/24

Scientists have found a rat-eating plant in far north Queensland. Perhaps they could start exporting them to London (where, folklore has it, one is never more than either six or 20 feet away from a rat, depending on whom you ask)?

(via /.) australia biology botany london queensland rats 0

2007/12/11

New research shows that the human race is evolving faster than ever, and that, far from the accepted truth of the human race being biologically homogeneous, different populations have, over the past 10,000 years, been evolving apart, pushed by different selection pressures:

“Genes are evolving fast in Europe, Asia and Africa, but almost all of these are unique to their continent of origin. We are getting less alike, not merging into a single, mixed humanity.
“Our study denies the widely held assumption that modern humans appeared 40,000 years ago, have not changed since and that we are all pretty much the same. We aren’t the same as people even 1,000 or 2,000 years ago.”
The scientists said this reflected the great increase in human populations over that period, which has allowed more beneficial mutations to emerge. Changes in the human environment, particularly the rise of agriculture, also created new selective pressure to which humans adapted.
Examples of evolutionary divergences include lactose tolerance among descendents of northern European populations (where the lack of sunlight would have made this mutation beneficial), differences in resistance to diseases such as malaria, smallpox and HIV between European and African populations, and more controversially, the hypothesis that above-average intelligence in Ashkenazi Jews is a result of selection pressures in mediaeval Europe (where they were confined to a small number of primarily cognitively demanding vocations). (And wasn't there a study a while ago that showed that the average IQ of a population was proportional to how many generations their ancestors had lived in urban environments?)

biology evolution genetics science society 0

2007/10/10

A new book takes to task the accepted belief that men and women think and/or communicate differently, as expounded by popular psychology books like Men Are From Mars, Women Are From Venus:

The bones of Cameron’s argument, set out in The Myth of Mars and Venus, are that Gray et al have no scientific basis for their claims. Great sheaves of academic papers, says Cameron, show that the language skills of men and women are almost identical. Indeed, the central tenets of the Mars and Venus culture – that women talk more than men, that men are more direct, that women are more verbally skilled – can all be debunked by scientific research. A recent study in the American journal Science, for instance, found men and women speak almost exactly the same number of words a day: 16,000.
Where the book becomes interesting is when she asks why we have become interested in these myths. “The first point to make is that in the past 20 years we have become obsessed by communication,” she says. “And that’s not just in relationships; it’s in customer care, it’s in politics. All problems are seen to be communication problems.
Cameron is not simply irritated that the Mars and Venus books have filled too many Christmas stockings. Her fervour on this issue runs deeper. There is, she thinks, something regressive, deeply conservative, in this outlook because what it seems to be saying is that we can’t change.
The author, Deborah Cameron, is a feminist philologist and Rupert Murdoch professor of Language at Oxford (really); other than the Mars-and-Venus brigade, she has in her sights Darwinists (which, I'm guessing, means the likes of Steven Pinker and/or Richard Dawkins), Tories, man-hating "pseudo-feminists" and punctuation/grammar pedants:
“You had people like Prince Charles and Norman Tebbit inferring that if people were making spelling mistakes it was only a short step to them coming in dirty to school and then there’d be no motivation for them to stay out of crime,” says Cameron. “There were these illogical slippery slope arguments: how, if children didn’t know how to use the colon properly, it was only a few steps from drug-taking and criminality. There was a deep moral and social dimension to it all.

biology communication culture gender human nature language neurology psychology science 0

2006/10/27

An article claims that sexual abstinence is bad for you:

Fans of abstinence had better be sitting down. "Saving yourself" before the big game, the big business deal, the big hoedown or the big bakeoff may indeed confer some moral benefit. But corporeally it does absolutely zip. There's no evidence it sharpens your competitive edge. The best that modern science can say for sexual abstinence is that it's harmless when practiced in moderation. Having regular and enthusiastic sex, by contrast, confers a host of measurable physiological advantages, be you male or female.
Its findings, published in 1997 in the British Medical Journal, were that men who reported the highest frequency of orgasm enjoyed a death rate half that of the laggards.
Other claimed benefits of regularly gettin' it on include: improved sense of smell, weight loss and overall fitness, pain relief, and reduced risks of heart disease, cancer, depression and incontinence.

(via MindHacks) biology science sex 0

2006/8/23

Scientists have created a mouse that's permanently happy. The mouse lacks the TREK-1 gene, which affects the transmission serotonin in the brain, and as such doesn't suffer from depression (which, presumably, normal mice do):

Mice without the TREK-1 gene ('knock-out' mice) were created and bred in collaboration with Dr. Michel Lazdunski, co-author of the research, in his laboratory at the University of Nice, France. "These 'knock-out' mice were then tested using separate behavioral, electrophysiological and biochemical measures known to gauge 'depression' in animals," says Dr. Debonnel. "The results really surprised us; our 'knock-out' mice acted as if they had been treated with antidepressants for at least three weeks."

(via /.) biology genetics happiness mouse science 0

2006/8/2

A biologist posits the intriguing hypothesis that a country's national character may be influenced by its rate of parasite infection, particularly by the parasite Toxoplasma gondii (i.e., the "crazy cat person" parasite):

The author of the study is Kevin Lafferty, a biologist at the University of California at Santa Barbara. Lafferty made three straightforward observations.
  1. Toxoplasma infection rates vary from country to country. South Korea has prevalance rate of only 4.3%, for example, while Brazil's rate is 66.9%. These rates are determined by many factors, from the eating habits in a country (steak tartar, anyone?) to its climate (Toxoplasma oocysts survive longer in warm tropical soil).
  2. Psychologists have measured some of the personality traits influenced by Toxoplasma in these countries. People with Toxoplasma tend to be more self-doubting and insecure, among other things. Among the differences in men, Toxoplasma is associated with less interest in seeking novelty. Toxoplasma-infected women are more open-hearted.
  3. A nation's culture can be described, at least in part, as the aggregation of its members' personalities.
Lafferty's hypothesis predicted that the national cultures/characters of countries with high rates of Toxoplasma infection would have higher rates of characteristics such as neuroticism, uncertainty avoidance and "masculine" sex roles:
He found a signficiant correlation between high levels of the parasite and high levels of neuroticism. There was a positive but weak correlation between Toxoplasma and levels of uncertainty avoidances and masculine sex roles. However, if he excluded the non-Western countries of China, South Korea, Japan, Turkey, and Indonesia, the correlations of both personality measurements with Toxoplasma got much stronger.
So--has Lafferty discovered why the French are neurotic (Toxo: 45%) and Australians are not (28%)? As he admits, this is just a first pass.
Lafferty also notes that many other factors shape a nation's culture--which actually raises another interesting question: what about other parasites? Do viruses, intestinal worms, and other pathogens that can linger in the body for decades have their own influence on human personality? How much is the national spirit the spirit of a nation's parasites?

(via Mind Hacks) biology cats culture national character parasites science toxoplasma gondii 0

2005/10/5

Freaky Trigger has one of the best music-book concepts I've seen:

The book was being edited by SR and was called Biology, named after the famous Old Skool Rave party organisation. It was a series of essays exploring the interface between biology and music taste - race, gender, endo/ectomorphs and dancing, the extent to which attractiveness defines taste (music scenes and the idea of "beautiful people"), notions of blindness in blues and rock, plus more general explorations of the theories of evolutionary biology as they might apply to pop! WOW, I thought, this sounds like it's going to be a great read! I was about to click and read more but then I woke up.
Unfortunately, it only exists in a dream.

(via catsgomiaow) biology culture evolution ideas music pop 1

2005/9/2

Scientists have developed mice which can regrow lost limbs or organs (or, in fact, everything other than brains).

Professor Heber-Katz made her discovery when she noticed the identification holes that scientists punch in the ears of experimental mice healed without any signs of scarring in the animals at her laboratory.
In one case the mice had their toes amputated -- but the digits grew back, complete with joints. In another test some of the tail was cut off, and this also regenerated. Then the researchers used a cryoprobe to freeze parts of the animals' hearts, and watched them grow back again. A similar phenomenon was observed when the optic nerve was severed and the liver partially destroyed.
Not only that, but cells from the mutant mice, injected into ordinary mice, confer the regenerative ability, and it is believed that it may confer greater longevity. The genes in question are believed to exist in humans as well.

biology mice science 0

2005/5/16

An interesting MSNBC article speculating on the future of human evolution, and interviewing scientists including Richard Dawkins:

Some environmentalists say toxins that work like estrogens are already having an effect: Such agents, found in pesticides and industrial PCBs, have been linked to earlier puberty for women, increased incidence of breast cancer and lower sperm counts for men.

"One of the great frontiers is going to be trying to keep humans alive in a much more toxic world," he observed from his Seattle office. "The whales of Puget Sound are the most toxic whales on Earth. Puget Sound is just a huge cesspool. Well, imagine if that goes global."

If we count humanity's technology as part of the evolving package &emdash; the extended phenotype, as Dawkins called it &emdash; then that will become part of the future of humanity, even if only due to the inevitable increase in pollution of an increasingly crowded Earth. Our descendants will have microscopic flotillas of nanobots in their bloodstreams, hunting down toxins and zapping proto-cancerous mutations. Perhaps corporations will remain the dominant species on earth, and the nanobots will be rented from the corporation that owns the patents for them; any human unlucky or imprudent enough to miss a payment can look forward to dying of massive organ failure, turning into a mass of tumours or having their suddenly naked immune system eaten alive by superbugs within 24 hours. Unless you live in the future's equivalent of Brazil or somesuch, in which case you'd get free open-source nanobots, considered by the America of the future to be pirated. But I digress.

Further on, the article speculates about whether humanity will diverge into different species, looking at Eloi/Morlocks scenarios, whether any sort of apocalyptic scenario could divide humanity into enough separate subgroups for them to evolve separately, and the question of body enhancement:

"You're talking about three different kinds of humans: the enhanced, the naturals and the rest," Garreau said. "The enhanced are defined as those who have the money and enthusiasm to make themselves live longer, be smarter, look sexier. That's what you're competing against."
In Garreau's view of the world, the naturals will be those who eschew enhancements for higher reasons, just as vegetarians forgo meat and fundamentalists forgo what they see as illicit pleasures. Then there's all the rest of us, who don't get enhanced only because they can't. "They loathe and despise the people who do, and they also envy them."

Then there is the question of germline genetic engineering, which could create instant races of superhumans or monsters, the AI singularity and even the vaguely retro-sounding prospect of spacefaring.

biology evolution genetic engineering science 4

2005/1/13

Between 60% and 80% of all naturally conceived embryos are spontaneously aborted without the woman or her partner ever knowing that they existed. The US Religious Right argue that every conceived embryo is, in moral terms, a human being, and, theologically speaking, has a soul. From this it follows that at least 40% of the population of Heaven are the souls of embryos that never experienced life: (via jwz)

Stepping onto dangerous theological ground, it seems that if human embryos consisting of one hundred cells or less are the moral equivalents of a normal adult, then religious believers must accept that such embryos share all of the attributes of a human being, including the possession of an immortal soul. So even if we generously exclude all of the naturally conceived abnormal embryospresuming, for the sake of theological argument, that imperfections in their gene expression have somehow blocked the installation of a soulthat would still mean that perhaps 40 percent of all the residents of Heaven were never born, never developed brains, and never had thoughts, emotions, experiences, hopes, dreams, or desires.

That's assuming that they go to Heaven; according to Dante, the unbaptised would go to Limbo, the uppermost circle of Hell, where they would mix with virtuous heathens.

(This conjures up all sorts of surreal questions and fictional scenarios, such as what relations between the two groups in Heavenly society. Would the embryos see themselves as purer than or superior to than the immigrants, sullied by the sinful world? Would the born-and-died be marginalised as second-class citizens, or form a culture of resentment of the establishment? Presumably Heaven is defined as an enlightened autocracy, ruled by an all-wise and benevolent God with vast bureaucracies and military orders of angels, who would keep the peace somehow. Though, if we transpose this to Philip Pullman's Republic of Heaven, would the Pure and the Dead have separate political parties bitterly contesting their interests in the Heavenly Parliament; or perhaps Heaven would be a fascist state run by the Pure?)

abortion afterlife biology dante eschatology heaven reductio ad absurdum religion theology 4

2004/4/9

Intestinal worms may prevent bowel cancer; as such, a health drink containing whipworm eggs to replenish your body's supply of the parasites symbionts may soon go on the market in Europe. The worms will be the pig variety, which doesn't survive long in humans, and is less likely to cause complications. (via FmH)

I wonder how long until we all have personalised populations of genetically engineered ex-parasites, modified to eliminate potential health problems long before any symptoms would arise, in our bowels, bloodstreams and elsewhere.

biology cancer health parasites 2

2003/12/12

When men experience stress, they respond with a flight-or-fight reaction; when women experience stress, they respond by maintaining friendships with other women:

Now the researchers suspect that women have a larger behavioral repertoire than just fight or flight; In fact, says Dr. Klein, it seems that when the hormone oxytocin is release as part of the stress responses in a woman, it buffers the fight or flight response and encourages her to tend children and gather with other women instead. When she actually engages in this tending or befriending, studies suggest that more oxytocin is released, which further counters stress and produces a calming effect. This calming response does not occur in men, says Dr. Klein, because testosterone---which men produce in high levels when they're under stress---seems to reduce the effects of oxytocin. Estrogen, she adds, seems to enhance it.

(I'm not so sure that stressed men don't experience the impulse to talk about it with friends; though maybe when they do, it's the result of a modern living and/or oestrogen-like chemicals in the water supply turning them into a bunch of big girls' blouses. Which ties into the whole nature-vs.-nurture debate.)

The discovery that women respond to stress differently than men was made in a classic "aha" moment shared by two women scientists who were talking one day in a lab at UCLA. There was this joke that when the women who worked in the lab were stressed, they came in, cleaned the lab, had coffee, and bonded, says Dr. Klein. When the men were stressed, they holed up somewhere on their own. I commented one day to fellow researcher Shelley Taylor that nearly 90% of the stress research is on males. I showed her the data from my lab, and the two of us knew instantly that we were onto something.

The article suggests that this difference between men's and women's responses to stress could be the reason why women outlive men on average.

biology gender nature vs. nurture stress 0

2003/11/16

A mother of three recently found out that she was not the biological parent of her children, all of whom were naturally conceived. As if that wasn't weird enough, it turns out that her DNA isn't her own either. "Jane", 52, is a tetragametic chimera, someone whose body is made up of two genetically different lines of cells. She is one of only 30 such individuals ever discovered. (via Lt. Wilkes)

biology bizarre genetics 2

2003/10/15

Chinese scientists create foetus with three parents (two female and one male). However, polyamorist group marriages in the West will have to wait a bit longer as such research is banned in the US and UK. Also, the foetus only contained genetic material from two of the parents; the third merely donated an egg. (Though perhaps some master-slave threesomes may not have a problem with such inequalities.)

biology china genetics 1

2002/7/29

Humans were biologically meant to be hugged, it appears. Scientists have discovered that the human skin has a special network of nerves whose sole purpose seems to be to feel pleasurable touches. The C-tactile (CT) nerves are independent from the normal touch receptors and operate at a slower rate; they hook into the unconscious aspect of touch, giving pleasure when stimulated.

"It must be used for unconscious aspects of touch because it is so slow," says Håkan Olausson, who led the study at the Department of Clinical Neurophysiology at Sahlgrenska University Hospital, Sweden. "It seems the CT network conveys emotions, or a sense of self."

biology neurology pleasure science 0

2000/11/14

Nobel laureate James Watson, co-discoverer of DNA, recently gave a talk at Berkeley, about the protein pom-C. In the talk, he made claims of biochemical connections between skin pigmentation, sexual activity, thinness and ambition, with more than the usual candour:

Witnesses were flabbergasted when the 72-year-old discoverer of the double helix suggested there was a biochemical link between exposure to sunlight and sexual urges. ``That's why you have Latin lovers,'' Watson said. ``You've never heard of an English lover. Only an English patient.''

The outcry of racism and sexism was immediate and resounding. The question is how much of that is because of Watson's abrasive style, and how much is the usual Marxist knee-jerk reaction against any concept of a biological basis for human nature?

biology james watson race racism sex the blank slate 0

2000/8/24

Researchers at the Institute of Psychology have discovered that men are biologically programmed to fall in love at the age of 50, dumping long-term partners and taking younger trophy wives. This phenomenon, termed the "Michael Douglas Syndrome", was no doubt an evolutionarily advantageous mutation, allowing men with this trait another chance to pass their genes on with a fit, fertile partner.

biology evolutionary psychology love michael douglas syndrome sex 0

2000/4/21

According to Oxford professor Brian Sykes, 99% of Europe's population is descended from one of seven women who lived in the past 45,000 years. (BBC News)

biology genetics 0

2000/4/7

The New York Times has an interesting piece on testosterone:

Studies have also shown that men in long-term marriages see their testosterone levels progressively fall and their sex drives subsequently decline. It is as if their wives successfully tame them, reducing their sexual energy to a level where it is more unlikely to seek extramarital outlets.
Men who are excessively testosteroned are not that attractive to most women. Although they have the genes that turn women on ... they can also be precisely the unstable, highly sexed creatures that childbearing, stability-seeking women want to avoid. There are two ways, evolutionary psychologists hazard, that women have successfully squared this particular circle. One is to marry the sweet class nerd and have an affair with the college quarterback: that way you get the good genes, the good sex and the stable home. The other is to find a man with variable T levels...
Those qualities associated with low testosterone -- patience, risk aversion, empathy -- can all lead to excellent governance. They are just lousy qualities in the crapshoot of electoral politics.
What if parents committed to gender equity opted to counteract the effect of testosterone on boys in the womb by complementing it with injections of artificial female hormones? That way, structural gender difference could be eradicated from the beginning. Such a policy would lead to "men and women with normal bodies but identical feminine brains," Matt Ridley posits. "War, rape, boxing, car racing, pornography and hamburgers and beer would soon be distant memories. A feminist paradise would have arrived."

biology evolutionary psychology sex society testosterone 0

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