Tuesday, January 10, 2012
Ostrich penis clears up evolutionary mystery
Overlooked bird organ is similar to, but separate from, that of reptiles and mammals.
From Nature
by ADAM MARCUS
A long-running question about how the largest species of birds achieve erect penises seems to have been settled. In a study published this week in the Journal of Zoology, researchers report that male ostriches and emus enlarge their penises using a burst of lymphatic fluid rather than a blood vascular system like that found in reptiles and mammals.
The finding, based on dissections, matches what is known about other species of birds — only 3% of which have penises — and could have important implications for the understanding of the shared, and divergent, evolutionary heritage of birds and reptiles.
"Our findings reveal that the evolution of a lymphatic erection mechanism likely occurred in the ancestor of all birds rather than within birds," says Patricia Brennan, an evolutionary biologist at the University of Massachusetts Amherst and one of the authors of the study.
Reproductive rarity
Ostriches and emus are members of the ratites, a group of flightless birds that also includes rheas and kiwis. All male ratites sport penises — as do ducks and some other species — but most birds mate instead with a brief 'cloacal kiss', during which the male passes sperm to the female through the cloaca, the same port used for excreting waste.
The existence of a lymphatic penis in some birds presents an evolutionary puzzle, says Richard Prum, an ornithologist at Yale University in New Haven, Connecticut, and co-author of the paper. “What is weird about birds is that they evolved not just a new structure, but a novel way to do something that was already being done,” he says.
It is a poorly explored area of avian anatomy, but speculation about the ratite penis dates back to at least 1836, when a German study suggested that it relied on blood for erection. Only a handful of scientists attempted to follow up on that finding, but a 1923 study claimed that the mechanism was lymphatic.
To settle the question, Prum and Brennan dissected the genitals of one adult ostrich (Struthio camelus) and three adult emus (Dromaius novaehollandiae). Both species turned out to have spongy, lymph-producing tissue, called paralymphatic bodies, just beneath the muscles that control the phallus. That is convincing evidence that the birds’ erections are controlled by the lymph system, the researchers say.
The origin of lymph-driven erections has yet to be uncovered. In ducks, says Brennan, it may reflect an “evolutionary arms race”. Male ducks often force sex on females to scatter their genes. Females have evolved complex anatomical defences against these unwanted attentions, but the lymphatic erection offers a way around these, because it allows a rapid on/off means of extending the penis and enabling deep insemination.
In ostriches and emus, the authors suggest, the system has a different role. Rather than elongating the penis, the lymph fluid may stiffen the organ while pushing semen towards the tip. The difference might reflect a different style of mating between the two, she says.
Divergent systems
The ratites may have a different erection mechanism from reptiles, but their phalluses aren't so dissimilar, anatomically speaking. "It was thought that the avian penis was an evolutionary novelty, rather than a shared trait with reptiles, partly because of the avian lymphatic erection,” explains Brennan. “Although our findings might be considered to support this view, we actually find that there are a lot of similarities between the reptile and ratite penis — for example, in the density and configuration of the tissue that makes up the penis in ostriches and emus, and that they likely evolved from the same tissues."
Robert Montgomerie, an evolutionary biologist at Queen’s University in Kingston, Canada, says it is remarkable that nobody has looked at this until now. Because ducks, ratites and other species all use a lymphatic system, the study shows that it must have been present in the common ancestor of all birds. But that system probably evolved more recently than the blood vascular arrangement in other vertebrates, says Montgomerie. “I think the evidence is that the lymph system is divergent,” he says.
Brennan is now conducting a survey of penis morphology in all birds that have the organ, to learn what differences and changes over time might say about their function and evolution. She says that there seems to be a strong correlation between genital size and bird mating habits. Emus, for example, pair bond, and the males have small penises. Rheas, on the other hand, have much larger phalluses and are promiscuous. “I’m hoping that as I add more data, I’ll get at why that is,” she says.
Montgomerie adds that the most provocative thing about the research is not what it says about bird penises, but rather what it implies about the lack of them for the vast majority of birds.
“Darwin and others said that penises were primary sexual traits, meaning they’re essential for reproduction. But the birds say they’re not,” notes Montgomerie. Instead, he says, the penis may be a secondary sexual trait, helpful for stimulating the female, signalling reproductive fitness and even an aspect of competition among males — but not indispensable.
Nature
doi:10.1038/nature.2011.9600
Rats Free Trapped Friends, Hint at Universal Empathy
from WIREDhttp://www.blogger.com/img/blank.gif
By Brandon Keim
With a few liberating swipes of their paws, a group of research rats freed trapped labmates and raised anew the possibility that empathy isn’t unique to humans and a few extra-smart animals, but is widespread in the animal world.
Though more studies are needed on the rats’ motivations, it’s at least plausible they demonstrated “empathically motivated pro-social behavior.” People would generally call that helpfulness, or even kindness.
“Rats help other rats in distress. That means it’s a biological inheritance,” said neurobiologist Peggy Mason of the University of Chicago. “That’s the biological program we have.”
In a study published Dec. 7 in Science, Mason and University of Chicago psychologists Jean Decety and Inbal Ben-Ami Bartal describe their rat empathy-testing apparatus: An enclosure into which pairs of rats were placed, with one roaming free and the other restrained inside a plastic tube. It could only be opened from the outside, which is exactly what the free rats did — again and again and again, seemingly in response to their trapped companions’ distress.
The experiment built on research conducted several years ago by geneticist Jeff Mogil at McGill University, where mice were shown capable of “emotional contagion” — a slightly scary-sounding term denoting a tendency to become upset when cagemates were in pain. This might not seem surprising, but anecdotes from wild animal observations don’t pass academic scrutiny, and it hadn’t before been shown in captive mice. It hinted at unexpectedly sophisticated cognition: Mice were supposed to feel pain, but not each other’s, at least not outside children’s stories.
At the time, ethologist Frans de Waal of Emory University, whose work has helped redefine what’s known scientifically about thoughts and feelings in chimpanzees and dolphins and elephants, said Mogil’s experiment “justifies speaking of ‘empathy’” — the ability to both put oneself in the shoes, or paws, of another, and to become emotionally involved in their situation. Sure, mice almost certainly weren’t so empathic as humans, but maybe they had the seeds of it. Maybe empathy wasn’t the result of some high-powered cognitive process, as most biologists and psychologists preferred to think, but a relatively simple phenomenon.
Wrote de Waal in Scientific American, “This mouse experiment suggests that the emotional component of this process is at least as old as the mammals and runs deep within us.”
Still, it was hard to know what to think, and emotional contagion didn’t equal empathy. Maybe the mice were simply fearful for themselves. But the possibility was open for investigation. And around the same time as the McGill studies, Bartal — then researching cancer in Israel — noticed rats at her lab becoming distressed when surgeries were performed on other rats. She couldn’t shake the feeling that empathy was involved. When she read about a rat bringing food to a trapped rat, she again thought about empathy.
Bartal went to the University of Chicago, where she joined with Decety, a leading scholar on empathy and prosocial behavior, and Mason, who’d been intrigued by Mogil’s work. Together they designed the new study — and not only did they find what might be empathy, but the rats acted on it.
Once rats learned to free their trapped and agitated partners, they did so almost immediately in trial after trial. The behavior was clearly deliberate. When the restrainer was empty, rats ignored it. When stuffed rats were restrained, the rats ignored them. “It’s compelling evidence that it’s the distress of the trapped cagemate motivating this helping behavior,” said Mason. “It is a huge leap up to use emotional contagion to actually do something, to actually help another individual.”
To make sure the rats weren’t responding to some immediate social reward — a rat version of a thank-you hug — the researchers tweaked the apparatus so that trapped rats were released into a separate cage. Again, the rats freed each other. When given the opportunity to eat chocolate treats first, rats were as likely to release their companions first, and even shared the chocolate with them.
“Empathy is a truly powerful motivator, on a par with the desire for chocolate!” said de Waal, who was not involved in the new study.
According to de Waal, the results “show for the first time that rodents are not just affected by the emotions of others, but that empathy motivates altruism.” He believes the rats responded to an instinctive urge to make their compatriots feel better, just as humans and chimpanzees and some cetaceans do. “The mechanism must ancient,” said de Waal.
However, the researchers stopped short of ascribing the results to a conclusive display of empathy. It’s possible the rats were less concerned with alleviating the suffering of brethren than soothing their own upset feelings. Perhaps the trapped rats’ distress calls were simply loud and annoying, and the free rats wanted to quiet them. One potentially important experimental condition — the opportunity for free rats to simply leave — wasn’t tested.
“The reservation I have is that it’s very difficult to demonstrate empathy. You have to show that the animal is putting itself in another’s shoes, and I’m not sure that’s demonstrated here,” said Joshua Plotnik, an Emory University psychologist and collaborator with de Waal. But Plotnik still called the observations “very exciting.”
According to Mason, further tests are planned in which rats’ stress responses will be damped by drugs. If a rat feels no distress itself but still frees a trapped companion, or if a trapped rat expresses no distress but is still rescued, empathy will seem more likely. “We can figure this question out. It’s completely tractable,” said Mason. “And this experimental model is unbelievably easy to set up. It’s our fervent hope this model will be used by many people to look at helping behavior.”
Cognitive mechanisms thought to underlie empathy and helpfulness could be tested, Mason said. So could the effects of personality traits, sex differences — females rats seemed more helpful, which tracks with studies of chimps and humans — or genetic and environmental variables. Indeed, the tests needn’t be restricted to rats, but could involve any species amenable to captivity.
For Bartal, whether rats were motivated by their companions’ distress or their own is less interesting than the simple fact they responded at all. “The bottom line here is that nature is very smart. Nature made it rewarding for us to end the suffering of another,” she said.
While the researchers didn’t discuss mechanisms underlying the possible empathy, Bartal and de Waal suspect it’s linked to the lengthy care and nursing provided, as in all mammals, by mother rats. “Mammals that need nurture and care after they’re born would require some form of empathic connection between mother and offspring,” Bartal said. Sociality could be another important factor. Rats live in large family groups with complex hierarchies, and empathy is especially important in social settings.
Rats also share basic neurological features, such as a highly developed limbic system and various hormones and neurotransmitters, with all other mammals. These could provide a common ancestral origin for empathy, said Bartal, or evolution could have shaped them independently in converging ways. All roads could lead to empathy.
Of course, mammals don’t have a monopoly on intelligence or sociality or maternal care. Octopi are extraordinarily smart. So are many birds, which also care for their young and can live in large colonies. The seeds of empathy, if that’s what the rats have, could be scattered widely. “Nature has an interesting way of using different structures for similar functions,” said Bartal.
Citation: “Empathy and Pro-Social Behavior in Rats.” By Inbal Ben-Ami Bartal, Jean Decety, Peggy Mason. Science, Vol. 334 Issue 6061, Dec. 9, 2011.
By Brandon Keim
With a few liberating swipes of their paws, a group of research rats freed trapped labmates and raised anew the possibility that empathy isn’t unique to humans and a few extra-smart animals, but is widespread in the animal world.
Though more studies are needed on the rats’ motivations, it’s at least plausible they demonstrated “empathically motivated pro-social behavior.” People would generally call that helpfulness, or even kindness.
“Rats help other rats in distress. That means it’s a biological inheritance,” said neurobiologist Peggy Mason of the University of Chicago. “That’s the biological program we have.”
In a study published Dec. 7 in Science, Mason and University of Chicago psychologists Jean Decety and Inbal Ben-Ami Bartal describe their rat empathy-testing apparatus: An enclosure into which pairs of rats were placed, with one roaming free and the other restrained inside a plastic tube. It could only be opened from the outside, which is exactly what the free rats did — again and again and again, seemingly in response to their trapped companions’ distress.
The experiment built on research conducted several years ago by geneticist Jeff Mogil at McGill University, where mice were shown capable of “emotional contagion” — a slightly scary-sounding term denoting a tendency to become upset when cagemates were in pain. This might not seem surprising, but anecdotes from wild animal observations don’t pass academic scrutiny, and it hadn’t before been shown in captive mice. It hinted at unexpectedly sophisticated cognition: Mice were supposed to feel pain, but not each other’s, at least not outside children’s stories.
At the time, ethologist Frans de Waal of Emory University, whose work has helped redefine what’s known scientifically about thoughts and feelings in chimpanzees and dolphins and elephants, said Mogil’s experiment “justifies speaking of ‘empathy’” — the ability to both put oneself in the shoes, or paws, of another, and to become emotionally involved in their situation. Sure, mice almost certainly weren’t so empathic as humans, but maybe they had the seeds of it. Maybe empathy wasn’t the result of some high-powered cognitive process, as most biologists and psychologists preferred to think, but a relatively simple phenomenon.
Wrote de Waal in Scientific American, “This mouse experiment suggests that the emotional component of this process is at least as old as the mammals and runs deep within us.”
Still, it was hard to know what to think, and emotional contagion didn’t equal empathy. Maybe the mice were simply fearful for themselves. But the possibility was open for investigation. And around the same time as the McGill studies, Bartal — then researching cancer in Israel — noticed rats at her lab becoming distressed when surgeries were performed on other rats. She couldn’t shake the feeling that empathy was involved. When she read about a rat bringing food to a trapped rat, she again thought about empathy.
Bartal went to the University of Chicago, where she joined with Decety, a leading scholar on empathy and prosocial behavior, and Mason, who’d been intrigued by Mogil’s work. Together they designed the new study — and not only did they find what might be empathy, but the rats acted on it.
Once rats learned to free their trapped and agitated partners, they did so almost immediately in trial after trial. The behavior was clearly deliberate. When the restrainer was empty, rats ignored it. When stuffed rats were restrained, the rats ignored them. “It’s compelling evidence that it’s the distress of the trapped cagemate motivating this helping behavior,” said Mason. “It is a huge leap up to use emotional contagion to actually do something, to actually help another individual.”
To make sure the rats weren’t responding to some immediate social reward — a rat version of a thank-you hug — the researchers tweaked the apparatus so that trapped rats were released into a separate cage. Again, the rats freed each other. When given the opportunity to eat chocolate treats first, rats were as likely to release their companions first, and even shared the chocolate with them.
“Empathy is a truly powerful motivator, on a par with the desire for chocolate!” said de Waal, who was not involved in the new study.
According to de Waal, the results “show for the first time that rodents are not just affected by the emotions of others, but that empathy motivates altruism.” He believes the rats responded to an instinctive urge to make their compatriots feel better, just as humans and chimpanzees and some cetaceans do. “The mechanism must ancient,” said de Waal.
However, the researchers stopped short of ascribing the results to a conclusive display of empathy. It’s possible the rats were less concerned with alleviating the suffering of brethren than soothing their own upset feelings. Perhaps the trapped rats’ distress calls were simply loud and annoying, and the free rats wanted to quiet them. One potentially important experimental condition — the opportunity for free rats to simply leave — wasn’t tested.
“The reservation I have is that it’s very difficult to demonstrate empathy. You have to show that the animal is putting itself in another’s shoes, and I’m not sure that’s demonstrated here,” said Joshua Plotnik, an Emory University psychologist and collaborator with de Waal. But Plotnik still called the observations “very exciting.”
According to Mason, further tests are planned in which rats’ stress responses will be damped by drugs. If a rat feels no distress itself but still frees a trapped companion, or if a trapped rat expresses no distress but is still rescued, empathy will seem more likely. “We can figure this question out. It’s completely tractable,” said Mason. “And this experimental model is unbelievably easy to set up. It’s our fervent hope this model will be used by many people to look at helping behavior.”
Cognitive mechanisms thought to underlie empathy and helpfulness could be tested, Mason said. So could the effects of personality traits, sex differences — females rats seemed more helpful, which tracks with studies of chimps and humans — or genetic and environmental variables. Indeed, the tests needn’t be restricted to rats, but could involve any species amenable to captivity.
For Bartal, whether rats were motivated by their companions’ distress or their own is less interesting than the simple fact they responded at all. “The bottom line here is that nature is very smart. Nature made it rewarding for us to end the suffering of another,” she said.
While the researchers didn’t discuss mechanisms underlying the possible empathy, Bartal and de Waal suspect it’s linked to the lengthy care and nursing provided, as in all mammals, by mother rats. “Mammals that need nurture and care after they’re born would require some form of empathic connection between mother and offspring,” Bartal said. Sociality could be another important factor. Rats live in large family groups with complex hierarchies, and empathy is especially important in social settings.
Rats also share basic neurological features, such as a highly developed limbic system and various hormones and neurotransmitters, with all other mammals. These could provide a common ancestral origin for empathy, said Bartal, or evolution could have shaped them independently in converging ways. All roads could lead to empathy.
Of course, mammals don’t have a monopoly on intelligence or sociality or maternal care. Octopi are extraordinarily smart. So are many birds, which also care for their young and can live in large colonies. The seeds of empathy, if that’s what the rats have, could be scattered widely. “Nature has an interesting way of using different structures for similar functions,” said Bartal.
Citation: “Empathy and Pro-Social Behavior in Rats.” By Inbal Ben-Ami Bartal, Jean Decety, Peggy Mason. Science, Vol. 334 Issue 6061, Dec. 9, 2011.
Pictures: "Lost" Leopard—And Poachers—Seen in Afghanistan
From National Geographic
Photograph courtesy WCS Afghanistan Program
This cat's out of the bag—a camera trap recently captured a Persian leopard in Afghanistan's central highlands, where the big cat had been thought locally extinct.
The newly released photographs, taken in the fall, include this September shot of an adult leopard investigating the camera, "appearing to threaten it with canines exposed," according to the Wildlife Conservation Society, which helped set up the camera traps. The images are "indisputable proof" that the big cat is hanging on in the region, the group said.
The camera traps also captured dozens of pictures of other wildlife species, including lynx, wild cats, wolves, red foxes, and stone martens.
"To see such a varied array of wildlife after we have endured so much conflict gives us hope for Afghanistan's future," Mostapha Zaher, director general of Afghanistan's National Environmental Protection Agency, said in a statement.
"Intact ecosystems represent a foundation for our country's reconstruction and development. This is also our heritage, our natural resources, our fauna and flora. It is incumbent upon all of us to conserve and protect our environment and hand it over to the next generation of the citizens of Afghanistan."
Vowels Control Your Brain
from NPR
by Robert Krulwich
"I"s make you see things differently than "O"s. Here's how. Say these words out loud:
Bean
Mint
Slim
These "I" and "E" vowels are formed by putting your tongue forward in the mouth.
That's why they're called "front" vowels.
Now, say:
Large
Pod
Or
Ought
Forward vowels vs. back vowels
With these words, your tongue depresses and folds back a bit. So "O", "A" and "U" are called "back" of the throat vowels.
OK, here's the weird part.
When comparing words across language groups, says Stanford linguistics professor Dan Jurafsky, a curious pattern shows up: Words with front vowels ("I" and "E") tend to represent small, thin, light things.
Back vowels ("O" "U" and some "A"s ) show up in fat, heavy things.
"It's not always true, but it's a tendency that you can see in any of the stressed vowels in words like little, teeny or itsy-bitsy (all front vowels) versus humongous or gargantuan (back vowels). Or the i vowel in Spanish chico (front vowel meaning small) versus gordo (back vowel meaning fat). Or French petit (front vowel) versus grand (back vowel)."
If I make up two words, "Frish" and "Frosh" and tell you each is about to become a new ice cream, which of the two seems richer, heavier?
For me, "Frosh," (with the back vowel "o") seems creamier. I don't know why. Just feels that way. And not just to me. A study in the Journal of Consumer Research found most people imagined Frosh creamier than Frish.
Here's another example. Richard Klink, a marketing professor at Loyola College in Maryland created a test using two sets of names. They were nonsense names, chosen at random:
Nidax vs. Nodax and Detal vs. Dutal
And then, slapping these names on various imaginary products, he asked a group of people:
Which brand of laptop seems bigger; Detal or Dutal?
Which brand of vacuum cleaner seems heavier, Keffi or Kuffi?
Which brand of ketchup seems thicker, Nellen or Nullen?
Which brand of beer seems darker, Esab or Usab?
"In each case," reports Professor Jurasky, "the participants in the study tended to choose the product named by back vowels (dutal, nodax) as the larger, heavier, thicker, darker product. Similar studies have been conducted in various other languages."
Jurasky then wondered, Do businesses know this about vowels?
For example, would an ice cream company (looking to create a rich, creamy and satisfying product,) and a cracker manufacturer, (looking to make something, thin, light and crackily) use different vowels?
He thought they might, so, on his blog, he writes:
To test the hypothesis I downloaded two lists of food names from the web. One was a list of 81 ice cream flavors that I constructed by including every flavor sold by either Haagen Dazs or Ben & Jerry's. The second was a list of 592 cracker brands from a dieting website. For each list, I counted the total number of front vowels and the total number of back vowels (details of the study are here). The result, shown in the table [below], is that ice creams names indeed have more back vowels and cracker names have more front vowels.
Ice cream companies mix in lots of "O"s and "A"s, says Jurasky, like...
Rocky Road, Jamoca Almond Fudge, Chocolate, Caramel, Cookie Dough, Coconut
But the cracker people stick pretty much to "E"s and "I"s.
Cheese Nips, Cheez It, Wheat Thins, Pretzel thins, Ritz, Krispy, Triscuit, Thin Crisps, Cheese Crisps, Chicken in a Biskit, Snack sticks, Toasted chips, Ritz bits
But Why?
Why do we associate "front" vowels with small, thin light things and "back" vowels with big, solid, heavy things?
Two linguists, John Ohala and Eugene Morton proposed that over evolutionary time, humans instinctively associate pitch with size. Lions, bears, seals make low sounds, canaries, mice, rabbits higher sounds. Not always, but enough of the time that when we hear a low frequency (even in an "O" or a "U") we may think big and heavy, whereas higher frequencies (even in "I's and "E"s) suggest small and light.
The Origin Of The Smile?
Dan Jurasky goes even further. Scholars have noticed, he says, that when people say "Boo!", they form an o-shape with their lips and mouth, and look aggressive and a little dangerous.
But use the "front" vowels, like "I" and "E", your mouth and lips will widen into a kind of smile. Why do we say "cheese" when it's time to take the picture? Why does the word smile contain an "I"? These front vowels, he says, are the "smile" vowels. One day they may even explain why we smile, but in the meantime, the big news is that it's old fashioned to think of vowels as just sounds.
They are more than that: they are little strings that pull on our brains and it turns out, "I"s pull us to different places than "O"s.
Who knew?
Chimp Murder in Mahale
Thanks to Carol RL for the link!
Go the Greystoke Mahale Blog to see images and read about a recent chimp murder at Mahale.
Molecular Anthropology Group - University of Oregon
My friend and Colleague Nelson Ting's Molecular Anthro page is now up and running - "like" it on facebook to stay up to date on his group's research and job opportunities!
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