How SHARK got his hammer

According to New Scientist, "It's one of evolution's most eccentric creations: a head shaped like a hammer. Now, a study suggests that the hammerhead shark may have evolved its oddly shaped snout to boost the animal's vision and hunting prowess."

For over a century, scientists have speculated why hammerheads evolved such an odd shape and whether having eyes so far apart would enhance their vision. In 1942 a leading authority on sharks, Gordon Walls, suggested the position of the shark's eyes prevented it from having binocular vision. But others have argued exactly the opposite, saying the animals must have enhanced eyesight.

Now, hammerhead sharks have had their first eye examination, and it has laid the debate to rest. Sharks with wider heads have better binocular vision – all the better to track fast-moving prey like squid with far more accuracy than sharks with close-set eyes.
The research also shows that hammerheads – among other sharks – have a 360-degree view of the world in the vertical plane, allowing them to simultaneously see prey above and below them.

Story teller: Michelle McComb of Florida Atlantic University

Source: Why the Hammer head shark got its hammer

How MOLE RAT got naked

ScienceDaily - Naked mole rats are strange, ugly, nearly hairless mouse-like creatures that live in underground communities. Unlike any other mammal, these communities consist of queens and workers more reminiscent of bees than rodents
They are 3-6 inches long, have pink furless skin, tiny eyes which never see the light of day, and long front teeth for digging.

Scientists call it "eusocial" in that the young are cared for by the group, individuals in the group give up their ability to reproduce in order to do other jobs, and there are at least two generations that overlap to do the family's work, Honeycutt noted.

"Biological evolution is generally seen as a competition, a contest among individuals struggling to survive and reproduce," said Dr Rodney Honeycutt.

"It runs counter to everything we know about evolution," Honeycutt said. "In fact, (Charles) Darwin himself said social animals represent a real challenge to his theory (of natural selection and individual fitness)."

Storyteller : Dr. Rodney Honeycutt, Texas A&M Univeristy
Source: Desparate Mole-Rats

How HUMAN controlled his urge

Lust is a universal preoccupation, one of the most compelling of the Seven Deadly Sins, new studies confirm. Whereas not only humans, but also birds and mammals, regularly engage in promiscuous, lecherous behaviour, researchers report that only people are capable of controlling such urges.

Studies at Northwestern University indicate that lust and cuckoldry are almost "compulsive" as a direct result of their impact on the brain's reward centres, which are foci of sensual interpretation. Erotic stimuli create a neurological frenzy.

Studies at Rutgers University, the State University of New York and elsewhere show infidelity and lewd behaviour in mammals and birds result from a "constellation of neural correlates." Researchers agree that lust probably evolved to generate mating behaviour among any appropriate partners.

Storyteller: Helen E. Fisher anthropology professor and human behavior researcher, Rutgers University

Humans alone can control lust, but most don't

How SPLEEN got some respect

Scientists have discovered that the spleen, long consigned to the B-list of abdominal organs and known as much for its metaphoric as its physiological value, plays a more important role in the body’s defense system than anyone suspected.

Reporting in the current issue of the journal Science, researchers describe studies showing that the spleen is a reservoir for huge numbers of immune cells called monocytes, and that in the event of a serious trauma to the body like a heart attack, gashing wound or microbial invasion, the spleen will disgorge those monocyte multitudes into the bloodstream to tackle the crisis. “The parallel in military terms is a standing army,” said an author of the report. “You don’t want to have to recruit an entire fighting force from the ground up every time you need it.”“Often, if you come across something in the body that seems like a big deal, you think, ‘Why didn’t anybody check this before?’ ” Dr. Nahrendorf said.

“But the more you learn, the more you realize that we’re just scratching on the surface of life. We don’t know the whole story about anything.”

Storyteller: Dr Matthias Nahrendorf, Massachusetts General Hospital and Harvard Medical School

Source : Finally, the Spleen Gets Some Respect

Vestigial Organs not so useless after all, Studies find

How PTEROSAUR learnt to FLY

A new study published February 17 in the journal PLoS One by researchers from Ohio University, College of the Holy Cross and the University of Leicester explains how balloon-like air sacs, which extended from the lungs to inside the skeleton of pterosaurs, provided an efficient breathing system for the ancient beasts. The system reduced the density of the body in pterosaurs, which in turn allowed for the evolution of the largest flying vertebrates.
"We offer a reconstruction of the breathing system in pterosaurs, one that proposes the existence of a mechanism with the same essential structure to that of modern birds — except 70 million years earlier," said study co-author Leon Claessens, an assistant professor of biology at the College of the Holy Cross

Storyteller: Leon Claessens, assistant professor of biology at the College of the Holy Cross
Source: Air-filled Bones Extended Lung Capacity And Helped Prehistoric Reptiles Take First Flight

How BEETLE got thirsty

A new study reports that seed beetles may be seeking out intimate moments not to increase their chances of becoming fertilized, but for hydration. "We were curious about the behavior of these females—males are known to inflict damage during mating, and yet the females keep going back for more," said study lead author Claudia Ursprung.

We wanted to find out whether females were getting food or drinks from the ejaculated fluid," said Ursprung, whose research appears in a recent issue of the journal Behavioral Ecology and Sociobiology. Ursprung and her colleagues kept 79 female seed beetles in enclosures for eight days. Some were given food and water, some just food, and some just water. In the absence of water but not food, females were much more likely to try breeding. Being given water, however, left the females with little appetite for sex.

The beetles probably evolved this bizarre tactic because the species lives in a dry environment, the researchers suspect. "It is kind of like a bribe for mating, a way of ensuring that the female will produce offspring," said co-author Darryl Gwynne, also at the University of Toronto.

Storyteller: Claudia Ursprung of the University of Toronto Mississauga.
Source: Love Thirsty Beetles

How the MOCKINGBIRD became a songwriter

Mockingbirds are the quintessential example of Darwinian evolution and were in fact Charles Darwin’s primary inspiration that led to his studies of evolution.
Evolutionary theory for some time seemed to point to the fact that mockingbird songs worked to attract mates, similar to the way a peacock’s feathers attract peahens. Mockingbirds, however, are monogamous birds, unlike peacocks, and both males and females sing the varied songs of their neighbors.
Different species of mockingbirds have purportedly mimicked everything from the songs of other birds, to machines, and even songs written by humans. Evidently, this proves that mockingbirds aren’t creatures of habit, even though the mimicry would seem to prove otherwise.
Evidently, songbirds learn their styles much in the same way a human child learns language. First, babbling, then practicing, until they are able to formulate their own songs. Most song birds stop, however, once they have perfected their song.
Mockingbirds, on the other hand, continue to learn and develop new sounds and songs through the duration of their lives, which seems to make the mockingbird a lover of learning new things. This skill makes it able to continuously adapt to its surroundings as well, which is another case of survival skills being put to the ultimate test.

Story Teller: The Berkley Daily Planet.
Source: “Mockingbird Jazz: The Evolutionary Roots of Bird Song,”

Story Researcher: This post was contributed by Holly McCarthy, who writes on the subject of an online university. She invites your feedback at hollymccarthy12 at gmail dot com

How NEANDERTHAL got his big nose

LONDON: Anthropologists have suggested that Neanderthals had big noses because of the degree to which their face used to jut forward, indicating that the odd feature was a fluke of evolution, not some grand adaptation. The Neanderthal nose has been a matter of befuddlement for anthropologists, who point out that modern cold-adapted humans have narrow noses to moisten and warm air as it enters the lung, and reduce water and heat loss during exhalation. Big noses tend to be found in people whose ancestors evolved in tropical climates
, where a large nasal opening helps cool the body. But Neanderthals go against this trend, according to Tim Weaver, a palaeoanthropologist at the University of California, Davis. "They were living in the glacial environment of Europe, colder than it is today, for most of the time," he said. "So, it's sort of been an anomaly. Why do they have these wide nasal apertures?," he wondered.

Storyteller: Tim Weaver, Palaeoanthropologist, University of California,
Source: Why Neanderthals had big noses

How TURTLE got her shell

A newly identified fossil could explain one of evolution's biggest mysteries – the origin of the turtle's shell. Bone fragments from a 210-million year-old, land-dwelling reptile from New Mexico suggest that the earliest turtles didn't have much of a shell at all. Over millions of years, rows of protective armour plates gradually fused together and to the reptile's vertebrae, eventually creating a complete shell. "Turtles ultimately originated from something that looked like an armadillo," says lead author Walter Joyce.

Exactly why turtles evolved their shell remains a mystery, Joyce says. A full shell might offer added protection and stability. And the proof could be in the pudding – their body plan is the world's oldest, changing little over 200 million years. "For some reason just being a turtle is an idea that came along and just really works," he says.

Storyteller: Walter Joyce, a palaeontologist, Peabody Museum of Natural History, Connecticut
Source: Fossil reveals how the turtle got its shell

Story research: Creation evolution headlines
Source: A turtle missing Link - Are we missing something?

How JELLYFISH got her sting

Jellyfish may owe thanks to a humble bacterium for their ability to sting prey. Scientists have found that one of the genes necessary for them to sting is similar to a gene in bacteria, suggesting the ancestors of jellyfish picked up the gene from microbes. The research is published this week in Current Biology.

"The result was a great surprise," says developmental biologist Nicolas Rabet of the Pierre and Marie Curie University in Paris, France, who led the team. "[This kind of] horizontal gene transfer is often neglected, and could sometimes be more important than we thought." Unlike vertical gene transfer from parent to offspring, the horizontal variety happens between organisms, or even between different species.

According to Casey Dunn , an evolutionary biologist who studies phylogenetic problems "There are other explanations for the incongruencies they see in the tree such as coevolution", but Rabet points out that that since the PGA synthase gene is approximately 1000 bases long, it is statistically unlikely to be the product of multiple distinct genes converging on the same sequence.

Storyteller: Nicolas Rabet of the Pierre and Marie Curie University in Paris, France
Source: How the Jellyfish got its sting

Story Researcher: Dave Scot, Uncommon Descent
Source: Tree of Life gets stung by JellyFish

How HUMAN got pregnant

Yale researchers have shown that the origin and evolution of the placenta and uterus in mammals is associated with evolutionary changes in a single regulatory protein, according to a report in Proceedings of the National Academy of Sciences.

Pregnancy is a biologically unusual situation where one organism lives and develops inside another that is genetically different. Ordinarily, the immune system identifies and destroys the dissimilar tissue as if it were a parasite. But in some early mammals, changes 'turned down' the immune system, allowing the developing embryo to grow and thrive unchallenged by the maternal immune response.

"New functions arise by using an existing tool from the gene regulatory 'toolbox' in a new or different place.

According to Yale graduate student Vincent Lynch, lead author of the study, "We are writing a different chapter. In this case the function of a major regulatory tool was altered — it is like we found a redesigned hammer."

Storyteller: Vincent Lynch, Yale graduate student

Source:Redesigned hammer that forged evolution of pregnancy in mammals found

How SNAKE got his fangs

"Many advanced snakes use fangs—specialized teeth associated with a venom gland to introduce venom into prey or attacker. Various front- and rear-fanged groups are recognized, according to whether their fangs are positioned anterior (for example cobras and vipers) or posterior (for example grass snakes) in the upper jaw A fundamental controversy in snake evolution is whether or not front and rear fangs share the same evolutionary and developmental origin".

"Our results suggest a new model for the evolution of snake fangs. A posterior subregion of the ancestral tooth-forming epithelium became developmentally uncoupled from the remaining dentition, resulting in posterior and anterior dental laminae that are developmentally independent."

Says PZ Meyers of Pharyngula "The key innovation in snake evolution was a subtle one, an uncoupling of two tooth-generating regions that opened the door to more flexibility in the modification of the jaws. The fang/venom gland complex probably evolved once in the common ancestor of these groups, but the elapids and vipers independently stumbled on a secondary change, the suppression of the anterior region, that allowed the posterior fangs to move forward to make a more effective poison delivery system.

Story Reteller: PZ Meyers of Pharyngula
Evolving snake fangs
Evolutionary origin and development of snake fangs

How VENUS got her trap

"The idea that plants – being the quintessence of peaceful
organisms standing at the basis of the food chain of life –
could themselves catch and eat animals, appeared so improbable to most botanists and other researchers that from the first descriptions in the fifteenth and sixteenth centuries
it took several hundred years for the carnivorous nature of these plants to be generally recognized ... The evolution of leaves with trap systems from noncarnivorous ones is mysterious, and there are no widely accepted hypotheses. Nachtwey concluded in 1959 concerning the origin of Utricularia’s trap that none of the contemporary evolutionary theories were able to answer these questions, and proposed that the answer might lie outside of the present scientific paradigms.

Story Researchers: Wolf-Ekkehard Lo¨nnig, and Heinz-Albert Becker, Max-Planck-Institute for Plant Breeding Research, Cologne, Germany
Source: Carnivorous plants

Story Researchers: Uncommon Descent
Source: Loennig and Becker on the origin of carnivorous plants

P.S. Since we have not yet found a story teller who has come up with even a slightly entertaining Darwinian Just So Story for the Venus Fly trap, we were forced to publish an article by two story researchers. Story Teller contributions are welcome. Love Dolly

How FISH learnt to grunt

"Next time you're at a loud singles bar, thank a fish for inspiration." Here's why: When a male midshipman fish eyes a competitor swimming too close, he chases off the interloper with an audible grunt. To attract a mate, he hums loudly for hours on end. Now these cries have attracted researchers seeking to figure out whether noisy animals, from fish to mammals, have a common ancestor that gave them the ability to vocalize. Researchers studied the larvae of three closely related species of bony fish—the midshipman fish, Gulf toadfish and oyster toadfish—that make sounds by squeezing their swim bladders up to 200 times per second. They report in Science that the parts of the brain and spinal cord that control the rhythm of those muscles develop in a pattern similar to that of other vocalizing animals, which suggests a common origin. Of course, the instruments being played by these brain cells—swim bladders in fish; the larynx in mammals—probably evolved independently. Think of that next time you're listening to a tall fishing story.

Storyteller: Andrew H. Bass, Department of Neurobiology and Behavior, Cornell University,

Evolutionary Origins for Social Vocalization in a Vertebrate Hindbrain–Spinal Compartment
Grunting, humming fish joins ancient chorus

How BIRD learnt to sing

The fastest muscles known lie within the throats of songbirds, according to new research on how birds vibrate their vocal cords. Superfast muscles were previously known only from the sound-producing organs of rattlesnakes, several fish and the ringdove. We now have shown that songbirds also evolved this extreme performance muscle type, suggesting these muscles -- once thought extraordinary -- are more common than previously believed."

Daniel Mennill, an avian biologist at the University of Windsor in Canada, noted that fieldwork has shown songbird vocalizations to be among the most precisely timed behaviors in the animal kingdom. "The synchronized duets and choruses of wrens, for example, are the most highly coordinated animal behaviors ever recorded," he said. "By having these extraordinary muscles, birds have a more precise control of their voice and can actively change the volume and frequency of their song faster than previously thought physically possible," Elemans says.

Storytellers: Coen Elemans, University of Utah
Superfast Vocal Muscles In Songbirds: Hundred Times Faster Than Blink Of An Eye

Song Function and the Evolution of Female Preferences: Why Birds Sing, Why Brains Matter

Story Research: Publication bias in the study of bird song

The Origin of Human Speech: an "all or nothing" jump!

How PLANT dressed up

Angiospermae: They're all around us. Look out almost any window and you'll see hundreds of them - the grass, the trees, the scraggly little weeds that force their way up between pavers. Our lives are shaped by them. In fact, we would never exist without them. They feed us, clothe us, inspire us. But where did they come from? At one point, researchers thought they had a pretty good idea of the origins of flowering plants, but in the past two decades molecular data have cruelly conspired to make our understanding far more shaky than it once was. They may rule the planet now, but they might as well have come from outer space. Where to next?

"Insect-attracting strobili such as found in Bennettitales could have quite easily given rise to the first flowers. Developmental genetics has confirmed the theory put forward many years previously that petals and sepals represent modified leaves, and by affecting the expression of the genes involved it has proved possible to make leaves grow instead of petals, and petals grow instead of leaves (Goto et al., 2001). So while we have still not entirely solved what Darwin so overquotedly referred to as the 'abominable mystery', the answer has drawn tantalisingly close." The Origin of flowers

Storyteller: Christoper Taylor
Storyreteller: Larry Moran, Department of Biochemistry, University of Toronto

The Evolution of flowering plants

How FROG got her claws out

Biologists at Harvard University have determined that some African frogs carry concealed weapons: When threatened, these species puncture their own skin with sharp bones in their toes, using the bones as claws capable of wounding predators.

"It's surprising enough to find a frog with claws," says Blackburn, a doctoral student in Harvard's Department of Organismic and Evolutionary Biology. "The fact that those claws work by cutting through the skin of the frogs' feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality."

"Most vertebrates do a much better job of keeping their skeletons inside," he adds.

Vertebrate claws are used in a variety of important behaviours and are typically composed of a keratinous sheath overlying the terminal phalanx of a digit. Keratinous claws, however, are rare in living amphibians; their microstructure and other features indicate that they probably originated independently from those in amniotes. Here we show that certain African frogs have a different type of claw, used in defence, that is unique in design among living vertebrates and lacks a keratinous covering.

Storytellers: David C. Blackburn, James Hanken, Farish A. Jenkins - Dept. Organismic and Evolutionary Biology Harvard University

When Threatened, A Few African Frogs Can Morph Toes Into Claws

How ADAM met STEVE

An Italian research team claims that the evolutionary origin and maintenance of male homosexuality in human populations could be explained by a model of sexually antagonistic selection.

"Male homosexuality is difficult to explain under Darwinian evolutionary models, because carriers of genes predisposing towards male homosexuality would be likely to reproduce less than average, suggesting that alleles (variations of the same gene) influencing homosexuality should progressively disappear from a population.

The model show the interaction of male homosexuality with increased female fecundity (fruitfulness) within human populations, in a complex dynamic, resulting in the maintenance of male homosexuality at stable and relatively low frequencies, and highlighting the effects of heredity through the maternal line.

"Our findings provide new insights into male homosexuality in humans. In particular, they promote a focus shift in which homosexuality should not be viewed as a detrimental trait (due to the reduced male fecundity it entails, but, rather, should be considered within the wider evolutionary framework of a characteristic with gender-specific benefits, and which promotes female fecundity. This may well be the evolutionary origin of this genetic trait in human beings."

Storytellers: Andrea Camperio Ciani and Giovanni Zanzotto at the University of Padova and Paolo Cermelli at the University of Torino

Male Homosexuality Can Be Explained Through A Specific Model Of Darwinian Evolution, Study Shows

How HUMAN caught the joke

The Pattern Recognition Theory of Humour by Alastair Clarke is an evolutionary and cognitive explanation of how and why an individual finds something funny. Effectively it explains that humour occurs when the brain recognizes a pattern that surprises it, and that this recognition is rewarded with the experience of the humorous response.” says Clarke.

Humour is not about comedy it is about a fundamental cognitive function. Clarke explains: “An ability to recognize patterns instantly and unconsciously has proved a fundamental weapon in the cognitive arsenal of human beings.” Recognising patterns enables us to quickly understand our environment and function effectively within it: language, which is unique to humans, is based on patterns.

Storyteller: Alastair Clarke
Humor Shown To Be Fundamental To Our Success As A Species

How BEE learned to dance

ScienceDaily (Jun. 10, 2008) — Asian and European honeybees can learn to understand one another's dance languages despite having evolved different forms of communication, an international research team has shown for the first time.

The nine species of honeybees found worldwide separated about 30 to 50 million years ago, and subsequently developed different dance 'languages'. The content of the messages is the same, but the precise encoding of these languages differs between species.

Now researchers from Australia, China and Germany have discovered that the two most geographically distant bee species -- the European honeybee Apis mellifera and the Asian honeybee Apis cerana -- can share information and cooperate to exploit new food sources.

Storytellers: Dr Shenglu Chen and Songkun Su from Zhejiang University in China and Dr Jürgen Tautz from Würzburg University in Germany
Honeybee Dance Breaks Down Cultural Barrier