NPR has an interesting little segment on the evolutionary advantages of religious beliefs. It speculates on the psychological relationship between religion, individual behaviour, group cooperation and government. Listen here.
August 7th, 2010
challenge the dogma
Maverick scientist James Lovelock on his approach to science.
His wikipedia page has a summary of his rather compelling argument for pro-nuclear environmentalism. He is probably most famous for his Gaia hypothesis.
July 26th, 2010
Would you like the fish, or the fish?
And interesting question from an old article at The Straight Dope:
Why didn’t Eskimos get scurvy before citrus was introduced to their diet? They have a traditional diet of almost entirely meat and fish. Where did they get their vitamin C?
And the answer:
This calls to mind a question I’ve dealt with before: Why do the Eskimos (or Inuit, as those in Canada and Greenland generally prefer to be called) stay there? It turns out that the people of the north have a highly evolved physiology that makes them well suited to life in the arctic: a compact build that conserves warmth, a faster metabolism, optimally distributed body fat, and special modifications to the circulatory system. One marvels at the adaptability of the human organism, of course, but still one has to ask: Wouldn’t it have been easier just to move to San Diego?
Much of what we know about the Eskimo diet comes from the legendary arctic anthropologist and adventurer Vilhjalmur Stefansson, who made several daredevil journeys through the region in the early 20th century. Stefansson noticed the same thing you did, that the traditional Eskimo diet consisted largely of meat and fish, with fruits, vegetables, and other carbohydrates–the usual source of vitamin C–accounting for as little as 2 percent of total calorie intake. Yet they didn’t get scurvy.
Stefansson argued that the native peoples of the arctic got their vitamin C from meat that was raw or minimally cooked–cooking, it seems, destroys the vitamin. (In fact, for a long time “Eskimo” was thought to be a derisive Native American term meaning “eater of raw flesh,” although this is now discounted.) Stefansson claimed the high incidence of scurvy among European explorers could be explained by their refusal to eat like the natives. He proved this to his own satisfaction by subsisting in good health for lengthy periods–one memorable odyssey lasted for five years–strictly on whatever meat and fish he and his companions could catch.
Read further at The Straight Dope.
July 24th, 2010
tree climbing or skinny dipping?
Last October I posted Elaine Morgan’s TED talk, in which she argues quite compellingly in favour of the “Aquatic Ape Theory”, a theory suggesting that there was an aquatic phase in our evolution.
Yesterday I discovered that there was a BBC documentary made in 1998 about Elaine and her championship of the theory. It’s on youtube in its entirety (Part 1, above).
It’s a good summary of the basis of the theory, and it also includes criticism of the theory by scientists.
April 8th, 2010
spending warm summer days indoors writing frightening verse to a buck-toothed girl in Luxembourg
The brains of shy or introverted individuals might actually process the world differently than their more extroverted counterparts, a new study suggests.
About 20 percent of people are born with a personality trait called sensory perception sensitivity (SPS) that can manifest itself as the tendency to be inhibited, or even neuroticism. The trait can be seen in some children who are “slow to warm up” in a situation but eventually join in, need little punishment, cry easily, ask unusual questions or have especially deep thoughts, the study researchers say.
The new results show that these highly sensitive individuals also pay more attention to detail, and have more activity in certain regions of their brains when trying to process visual information than those who are not classified as highly sensitive.
Role in evolution
The sensitivity trait is found in over 100 other species, from fruit flies and fish to canines and primates, indicating this personality type could sometimes provide an evolutionary advantage.
Biologists are beginning to agree that within one species there can be two equally successful “personalities.” The sensitive type, always a minority, chooses to observe longer before acting, as if doing their exploring with their brains rather than their limbs. The other type “boldly goes where no one has gone before,” the scientists say.
The sensitive individual’s strategy is not so advantageous when resources are plentiful or quick, aggressive action is required. But it comes in handy when danger is present, opportunities are similar and hard to choose between, or a clever approach is needed.
More (livescience)
February 7th, 2010
evolution respects gays?
From the excellent EurekAlert!:
Male homosexuality doesn’t make complete sense from an evolutionary point of view. It appears that the trait is heritable, but because homosexual men are much less likely to produce offspring than heterosexual men, shouldn’t the genes for this trait have been extinguished long ago? What value could this sexual orientation have, that it has persisted for eons even without any discernible reproductive advantage?
One possible explanation is what evolutionary psychologists call the “kin selection hypothesis.” What that means is that homosexuality may convey an indirect benefit by enhancing the survival prospects of close relatives. Specifically, the theory holds that homosexual men might enhance their own genetic prospects by being “helpers in the nest.” By acting altruistically toward nieces and nephews, homosexual men would perpetuate the family genes, including some of their own.
Two evolutionary psychologists, Paul Vasey and Doug VanderLaan of the University of Lethbridge, Canada tested this idea for the past several years on the Pacific island of Samoa. They chose Samoa because males who prefer men as sexual partners are widely recognized and accepted there as a distinct gender category—called fa’afafine—neither man nor woman. The fa’afafine tend to be effeminate, and exclusively attracted to adult men as sexual partners. This clear demarcation makes it easier to identify a sample for study.
Fascinating article — if, at the very least, only to hear of the Fa’afafine as an accepted third gender in Samoa — and an interesting theory… Although I’m not sure where it leaves lesbians. Are they super aunties? Article at EurekAlert!
February 6th, 2010
frogosaurus lives
Hurray, I’m now a Cambridge certified EFL teacher! And for the moment I have a much more relaxed schedule, so my blog will see more love than it has in past weeks. Starting with this fantastic creature, Japan’s Giant Salamander.
But impressive it certainly is: about 1.7m (5ft 6in) long, covered in a leathery skin that speaks of many decades passed, with a massive gnarled head covered in tubercles whose presumed sensitivity to motion probably helped it catch fish by the thousand over its lifetime.
If local legend is to be believed, though, this specimen is a mere tadpole compared with the biggest ever seen around Maniwa.
A 17th Century tale, related to us by cultural heritage officer Takashi Sakata, tells of a salamander (or hanzaki, in local parlance) 10m long that marauded its way across the countryside chomping cows and horses in its tracks.
It’s referred to as a “living fossil” because its skeleton still resembles closely that of 30 million year old examples (see right).
The full article describes the creature’s highly unusual manner of (external) fertilization. It sounds almost as alien as slug sex. It really is from another world: see the video and accompanying article @ BBC News.
Photo by wikipedia user Haplochromis.
January 9th, 2010
the secret world of ‘water bears’ (aka ‘moss piglets’ aka ‘tardigrades’)
Image via flickr (though probably didn’t originate there)
Tardigrades (meaning “slow walkers”) are microbial creatures that are resilient against all manner of extreme conditions (heat, cold, pressure, radiation, dehydration). They can survive in temperatures as low as 1 degree calvin — 0 degrees calvin being the temperature at which molecular motion ceases. They can survive space. They can survive being dehydrated and rehydrated like instant coffee.
They’re extremely common (there are probably some in your back garden) and examples have been found dating back to the Cambrian period, when they were less evolved: fewer legs, simpler head shape and no posterior appendages.
Image via the incredible water bear.
They occupy their own phylum in the animal kingdom (tardigrada), they are so unique. Their closest relatives are fruit flies (arthropoda) and nematodes (nematoda).
More info at Wikipedia, where there are links to yet more info, photos, and videos.
January 7th, 2010
it’s a wuzzy line and its getting wuzzier
“The Unbroken Thread” is the latest and greatest musical-science-mashup by youtuber MelodySheep. Uplifting!
See also: Previous Attenborough-related posts
November 27th, 2009
why are whales so big?
Photo: LIFE
And for that matter, what’s to stop them being bigger? I like seemingly simple questions like these that we take for granted, because they often give way to a beautiful cascade of information by way of explanation. Discover magazine has a nice article called “The Origin of Big”, that plots the course of the whale’s evolution.
Simply put: In order to harvest enough microscopic krill from the sea to provide their energy, they have to eat a LOT. In order to take big enough sifting gulps, they need a big mouth. In order to have a big mouth, they need a big body. In order to power a big body, they need… more krill! So they just kept growing until they had reached the optimum level (if they got to require too much energy, they would become too vulnerable if food supplies should wane even temporarily).
In growing so large they face certain logistical problems. They are taking on enough water in each gulp to make their body weight twice as much (sometimes more) as usual. How do they cope? Discover on a recent report:
If a whale simply let the water come rushing in, there would be a tremendous collision–more than a whale could handle. Instead, the scientists argue, the whales actively cradle their titanic gulp. As the water rushes in, the whales contract muscles in their lower jaw. The water slows down and then reverses direction, so that it’s moving with the whale. (It just so happens that fin whales do have sheets of muscle and pressure-sensinging nerve endings in their lower jaw. Before now, nobody quite knew before what they were for.) Once the water is moving forward inside the whale it can then close its mouth and give an extra squeeze to filter the water through its baleen.
…
As their body increases in size, the energy their bodies demand rises faster than the extra energy they can get from their food.
This scaling may explain some of the weird diving patterns found in lunge-feeding whales. Blue whales are twice as big as humpback whales, for example, but both species dive for the same period of time (about eight minutes) and to the same depth (148 meters). All things being equal, you’d expect that blue whales would be able to dive deeper and longer, because they could store more oxygen in their bigger bodies. Blue whales also make fewer lunges than humpback whales (6 versus 15). It’s possible that the gigantic blue whales are hard up against a size limit. They need so much energy for their lunges that they can’t afford to hold their breath longer, and they can only manage to make a few lunges before they run out of reserves and have to head for the surface.
November 16th, 2009
the shameful plant
A demonstration of sensitive plants or Mimosa Pudica, which respond to heat and touch. It’s clearly a plant that’s captured peoples’ imaginations as it goes by many other names: touch-me-not, humble plant, shameful plant, sleeping grass…
Wikipedia on the plants ability to move:
It is not known exactly why Mimosa pudica evolved this trait, but many scientists think that the plant uses its ability to shrink as a defense from predators. Animals may be afraid of such a fast moving plant and would rather go and eat a less active one.
November 2nd, 2009
which came first: the quale egg or the self
October 27th, 2009
i think i’m in love
If I make it to my eighties and i’m as charismatic and on-the-ball as Elaine Morgan, i’ll count myself very fortunate. Here she is championing the theory that humans evolved at some point in history in a water-based environment (the “aquatic ape theory”).
I have no idea if the theory holds any water (pun not intended) but I admire its fantastic latitude. I also feel somewhat calmed to know that, under this theory, my burgeoning gut may have some sort of evolutionary justification.
October 12th, 2009
mother nature sets our bedtime
And she knows that she knows better (4 billion years of experience can make one very cocksure), so you needn’t bother answering back.
Foster and Kreitzman argue that modern society “is in conflict with our basic biology”. Electric lights turn night into day and central heating transforms our homes into oases of summer warmth in bleak midwinter. When we feel sleepy we don’t listen to our bodies. Instead we drink another cup of coffee, roll down the car window and “kid ourselves that we can beat a few billion years of evolution.”
Guilty as charged, I should be asleep but technology has encouraged a rebellion against dear Mother Nature. The above is from PD Smith’s review of Rhythms of Life at the independent.
Smith’s personal blog is incidentally very attractive. Nice design by Jean-Michel Dentand.
September 10th, 2009
death stinks! rather distinctively actually.
Apparently many animals have the ability to smell death. The smell of certain fatty acids (presumably decomposing) is enough to warn some animals instinctively that something is amiss. This mechanism likely evolved over 400 million years ago as a means of protecting animals from contagious illnesses and localized predators, according to this rather edifying BBC News article which lays out the history of this discovery.
Various mammals, including deer, groundhogs and rabbits will avoid the smell of blood. They also avoid the smell of various soaps, which are largely comprised of fatty acids
Rats will seal up burrow entrances that have been treated with cat litter, but it is not known what actual smell is the deterrent, or whether it is specific to cats or faeces
Mice can tell if another has been exposed to radiation or is carrying a virus
More at BBC NEWS
June 16th, 2009
original syn
The New York Times has an article attempting to plot our progress to date in working out the puzzle of life’s origins on Earth.
So little fossil evidence has been found to explain the origins of life on Earth that scientists, in order to figure out how life may have begun, are taking the approach of attempting to recreate the conditions that might make this spontaneous synthesis of living cells possible. But there are many theories as to what these conditions might have been.
The three researchers, Jack W. Szostak, David P. Bartel and P. Luigi Luisi, published a somewhat adventurous manifesto in Nature in 2001, declaring that the way to make a synthetic cell was to get a protocell and a genetic molecule to grow and divide in parallel, with the molecules being encapsulated in the cell. If the molecules gave the cell a survival advantage over other cells, the outcome would be “a sustainable, autonomously replicating system, capable of Darwinian evolution,” they wrote.
“It would be truly alive,” they added.
June 1st, 2009
why we love a good yarn
Scientific American (August 07) offers an illuminating probe into the human predilection for storytelling, drawing evolutionary conclusions from anthropological comparisons in how we have historically told stories.
One hypothesis is that by engaging with fiction we are practising in our minds social behaviours and situations. Another suggests that telling stories is simply the best way of sharing important information amongst groups.
But the best stories—those retold through generations and translated into other languages—do more than simply present a believable picture. These tales captivate their audience, whose emotions can be inextricably tied to those of the story’s characters. Such immersion is a state psychologists call “narrative transport.”
Researchers have only begun teasing out the relations among the variables that can initiate narrative transport. A 2004 study [...] showed that prior knowledge and life experience affected the immersive experience. Volunteers read a short story about a gay man attending his college fraternity’s reunion. Those who had friends or family members who were homosexual reported higher transportation, and they also perceived the story events, settings and characters to be more realistic. Transportation was also deeper for participants with past experiences in fraternities or sororities. “Familiarity helps, and a character to identify with helps,” Green explains.
One result of our evolutionary bent for engaging a narrative is that we now appear to be more open to accepting new ideas when they come in the form of a story. When we expect fact, we raise our critical barriers.
Advertisers have long taken advantage of narrative persuasiveness by sprinkling likable characters or funny stories into their commercials. A 2007 study by marketing researcher Jennifer Edson Escalas of Vanderbilt University found that a test audience responded more positively to advertisements in narrative form as compared with straightforward ads that encouraged viewers to think about the arguments for a product. Similarly, Green co-authored a 2006 study that showed that labeling information as “fact” increased critical analysis, whereas labeling information as “fiction” had the opposite effect. Studies such as these suggest people accept ideas more readily when their minds are in story mode as opposed to when they are in an analytical mind-set.
A fantastic example is provided of a good story’s impact:
Works of fiction may even have unexpected real-world effects on people’s choices. Merlot was one of the most popular red wines among Americans until the 2005 film Sideways depicted actor Paul Giamatti as an ornery wine lover who snubbed it as a common, inferior wine. Winemakers saw a noticeable drop in sales of the red wine that year, particularly after Sideways garnered national attention through several Oscar nominations.
More at Sci Am
May 19th, 2009
misery works!
“When you find something this deeply in us biologically, you presume that it was selected because it had some advantage, otherwise we wouldn’t have been burdened with it,” says Jerome Wakefield, a clinical social worker at New York University
…
Hard evidence for the importance of sadness in humans is difficult to come by, but there are lots of ideas about why our propensity to feel sad might have evolved. It may be a self-protection strategy, as it seems to be among other primates that show signs of sadness. An ape that doesn’t obviously slink off after it loses status may be seen as continuing to challenge the dominant ape – and that could be fatal.
Here’s a fascinating article from January’s NewScientist which ponders the evolutionary benefits of depression (amongst other related questions).