Most mammals can sprint faster than humans — having four legs gives them the advantage. But when it comes to long distances, humans can outrun almost any animal. Because we cool by sweating rather than panting, we can stay cool at speeds and distances that would overheat other animals. On a hot day, the two scientists wrote, a human could even outrun a horse in a 26.2-mile marathon.

Why would evolution favor the distance runner? The prevailing theory is that endurance running allowed primitive humans to incorporate meat into their diet. They may have watched the sky for scavenging birds and then run long distances to reach a fresh kill and steal the meat from whatever animal was there first.

Other research suggests that before the development of slingshots or bows, early hunters engaged in persistence hunting, chasing an animal for hours until it overheated, making it easy to kill at close range. A 2006 report in the journal Current Anthropology documents persistence hunting among modern hunter-gatherers, including the Bushmen in Africa.[...]

There is other evidence that evolution favored endurance running. A study in The Journal of Experimental Biology last February showed that the short toes of the human foot allowed for more efficient running, compared with longer-toed animals. Increasing toe length as little as 20 percent doubles the mechanical work of the foot. Even the fact that the big toe is straight, rather than to the side, suggests that our feet evolved for running.

Link via Instapundit | Image: U.S. Secret Service

The grandmother hypothesis suggests that humans have “given up” their reproductive potential in later years in order to invest in the children they already have as well as their grandchildren. Naturally, this is an unconscious, biological adaptation that emerges over many generations and is not the result of individual decision-making. For such a hypothesis to be confirmed it would have to be demonstrated that children are significantly more likely to survive when a grandmother is present than when she isn’t.

Dr. Lummaa has done just that in her study published in the journal Nature, demonstrating that children are 12% more likely to survive to adulthood when they have a grandmother’s support than when they don’t.

Let’s hear it for grandmas! Link

In apes—both modern apes and, presumably, the ancient ancestors of Ardipithecus—males find mates the good old-fashioned apish way: by fighting with other males for access to fertile females. Success, measured in number of offspring, goes to macho males with big sharp canine teeth who try to mate with as many ovulating females as possible. Sex is best done quickly—hence those penis bristles, which accelerate ejaculation—with the advantage to the male with big testicles carrying a heavy load of sperm. Among females, the winners are those who flaunt their fertility with swollen genitals or some other prominent display of ovulation, so those big alpha dudes will take notice and give them a tumble, providing a baby with his big alpha genes.

Let’s suppose that some lesser male, with poor little stubby canines, figures out that he can entice a fertile female into mating by bringing her some food. That sometimes happens among living chimpanzees, for instance when a female rewards a male for presenting her with a tasty gift of colobus monkey.

Among Ardipithecus’s ancestors, such a strategy could catch on if searching for food required a lot of time and exposure to predators. Males would be far more successful food-providers if they had their hands free to carry home loads of fruits and tubers—which would favor walking on two legs. Females would come to prefer good, steady providers with smaller canines over the big fierce-toothed ones who left as soon as they spot another fertile female. The results, says Lovejoy, are visible in Ardipithecus, which had small canines even in males and walked upright.

Jamie Shreeve of NGM Blog Central has the story: Link

White and his colleagues found so many teeth of different Ardipithecus individuals that they could compare male and female canines with some confidence. The male teeth turn out to be surprisingly blunted. This result suggests that hominids shifted away from a typical ape social structure early in our ancestry. If this was a result of males forming long-term bonds with females and helping raise young, this shift was able to occur while hominids were still living a very ape-like life. Ardipithecus existed about 2 million years before the oldest evidence of stone tools, suggesting that technology was not the trigger for the evolution of nice hominid guys.

There have been a couple of hominid bones found that are even older than Ardipithecus, but none with enough fossils to even begin reconstructing a skeleton. Link -via Metafilter

A private owner has donated a fossil that could change the way we think about Tyrannosaurus and their development.

Some scientists believed the T.Rex evolved to its enormous size, then its arms shrank, when they were no longer needed.  The new discovery, though, shows that the tiny-armed killing machine may have evolved from a much smaller killing-machine-with-tiny-arms.  This totally rearranges the previous T.Rex evolution paradigm.

The 125 million-year-old fossil dinosaur, unearthed in China and dubbed Raptorex kriegsteini, is “as close to the proverbial missing link on a lineage as we might ever get for tyrannosaurs,” Sereno said.

Link

(As a special bonus, check out the religious debate in the comments.)

From the Upcoming ueue, submitted by HeartlessMachine.

Given the possibility of being deceived, it would have been rather foolish of our ancestors to take at face value a person’s verbal or behavioral expressions of remorse. Instead, over tens of thousands of years, uncontrollable blushing would have evolved as a fairly reliable predictor of the actor’s future behavior. In other words, if the behavior or situation at issue made the person feel so uncomfortable that his or her facial veins dilated—a physiological response that for many people is attended by a somewhat unpleasant tingling sensation—the blusher would probably avoid repeating that behavior in the future. Thus, blushing seems to be an appeasement display. Interestingly, this evolutionary hypothesis is aligned with a recent argument advanced by neuroscientist Mark Changizi in his book The Vision Revolution (BenBella, 2009). Among other things, Changizi claims that our species unusually strong color vision evolved so that we could detect subtle hue changes in other peoples’ skin, thereby deducing their emotions.

Link

Image by flickr user SanFranAnnie used under creative commons license.

Trying to plumb the canine mind is a favorite pastime of dog owners. “Everyone feels like an expert on their dog,” says Alexandra Horowitz, a cognitive scientist at Barnard College and author of the new book Inside of a Dog: What Dogs See, Smell, and Know. But scientists had carried out few studies to test those beliefs–until now.

This fall, [Duke University anthropologist Brian] Hare is opening the Duke Canine Cognition Center, where he is going to test hundreds of dogs brought in by willing owners. Marc Hauser, a cognitive psychologist at Harvard University, recently opened his own such research lab and has 1,000 dogs lined up as subjects. Other facilities are operating in the U.S. and Europe.

What they’ve found out so far is that dogs can learn over 200 distinctive human words, but they may mean different things to a dog than to humans. And the intelligent, friendly, and obedient behavior we see in dogs evolved because those things are advantageous to the dog, even though we see them as advantageous to us. Link -via Metafilter

(image credit: D.L. Anderson)

If you could travel back to 130 million years ago, you might not be impressed with the earliest flowers. “They didn’t look like they were going anywhere,” Dr. Doyle said.

Those early flowers were small and rare, living in the shadows of far more successful nonflowering plants. It took many millions of years for flowers to hit their stride. Around 120 million years ago, a new branch of flowers evolved that came to dominate many forests and explode in diversity. That lineage includes 99 percent of all species of flowering plants on Earth today, ranging from magnolias to dandelions to pumpkins. That explosion in diversity also produced the burst of flower fossils that so puzzled Darwin.

Genetic research is providing answers to how plants can switch on genes that control how different plants parts grow, and to use sexual reproduction to increase genetic diversity. Link

One of the first traits that differentiated humans from our ancestors was upright gait. There are several hypotheses about the emergence of this trait, but it seems to have offered a way to move more efficiently in open environments such as the savanna. Although our earliest human ancestors were very apelike in terms of their brains, their upright gait had changed their pelvis to look much like our modern one. This reshaped pelvis came with a narrower birth canal, making childbirth more difficult.

Meanwhile the new roaming grounds afforded advantages in acquiring resources and negotiating social relationships to those with flexible, problem-solving behavior. Over time, natural selection increased brain size in these early humans. But at some point, the selection for bigger and bigger brains collided head-on, so to speak, with the narrow pelvis. If babies’ heads got any bigger, they would get stuck in the birth canal and kill both mother and child. Although natural selection worked to maximize what could be done—for instance, babies’ heads compress as they twist their way around the bones in the pelvis—there simply is not enough room for a big, mature brain to pass through.

Therefore, Bock explains, human baby brains continue to develop substantially after birth and it takes longer for them to learn how to walk.

Link

Image by flickr user BadrNaseem used under creative commons license

“Crying is a highly evolved behavior,” said researcher Oren Hasson, an evolutionary biologist at Tel Aviv University in Israel. “My analysis suggests that by blurring vision, tears lower defenses and reliably function as signals of submission, a cry for help, and even in a mutual display of attachment and as a group display of cohesion.”

Crying as a social behavior? What do you think? Link -via Digg

Depressed people often think intensely about their problems. These thoughts are called ruminations; they are persistent and depressed people have difficulty thinking about anything else. Numerous studies have also shown that this thinking style is often highly analytical. They dwell on a complex problem, breaking it down into smaller components, which are considered one at a time.

This analytical style of thought, of course, can be very productive. Each component is not as difficult, so the problem becomes more tractable. Indeed, when you are faced with a difficult problem, such as a math problem, feeling depressed is often a useful response that may help you analyze and solve it. For instance, in some of our research, we have found evidence that people who get more depressed while they are working on complex problems in an intelligence test tend to score higher on the test.

Link via Instapundit

Photo credit: Guillermo Perales Gonzalez

First the ancestral plant must have adapted to move its tentacles and leaves in a particular direction, giving it a greater chance of sticking to and engulfing a passing insect.

Next it sped up how quickly it detected prey and tried to respond.

Then the plant would have had to find a way to become selective, so it only tried to trap live prey and not any detritus that landed upon it.

Finally, it must have evolved its tentacles into sensory hairs and teeth that detect and wrap around prey, respectively, while also losing its sticky glands and growing new digestive glands capable of digesting the victim’s corpse.

The adaptations led to the plant’s ability to eat larger insects for more nutrition. Link -via the Presurfer

The shell itself is made from broadened and flattened ribs, fused to parts of the turtle’s backbone (so that unlike in cartoons, you couldn’t pull a turtle out of its shell). The shoulder blades sit underneath this bony case, effectively lying within the turtle’s ribcage. In all other back-boned animals, whose shoulder blades sit outside their ribs (think of your own back for a start). The turtle’s torso muscles are even more bizarrely arranged.

Ed Yong looks at turtle anatomy and how this weird configuration evolved from the basic vertebrate plan. Link

Forget DNA! Scientists have re-traced our evolutionary tree and confirmed human’s relationship to fellow apes through laughter.

Who says you can’t learn anything by tickling chimps?

To investigate that, Marina Davila Ross of the University of Portsmouth in England and colleagues carried out a detailed analysis of the sounds evoked by tickling three human babies and 21 orangutans, gorillas, chimps and bonobos.

After measuring 11 traits in the sound from each species, they mapped out how these sounds appeared to be related to each other. The result looked like a family tree. Significantly, that tree matched the way the species themselves are related, the scientists reported online Thursday in the journal Current Biology.

They also concluded that while human laughter sounds much different from the ape versions, its distinctive features could well have arisen from shared ancestral traits.

After measuring 11 traits in the sound from each species, they mapped out how these sounds appeared to be related to each other. The result looked like a family tree. Significantly, that tree matched the way the species themselves are related, the scientists reported online Thursday in the journal Current Biology.

Link

From the Upcoming ueue, submitted by Gauldar.

Seagrasses, which thrive in shallow water, spread rapidly through these newly formed environments. The researchers think that the ancestors of modern seahorses followed.

Horizontally swimming fish living in seagrass beds don’t blend into the environment well and are easily picked off by predators.

A solution seems to have evolved in seahorse ancestors: the upright body shape, which enables seahorses to seamlessly blend in with surrounding seagrass.

Link

(Photo: Robert Sisson / NGS)

Paleontologist Jorn Hurum lead a team of scientists to analyze a 47-million-year-old fossil above (named "Ida") and came up with this intriguing conclusion: it is a critical missing-link species in the evolution of primates!

The fossil, he says, bridges the evolutionary split between higher primates such as monkeys, apes, and humans and their more distant relatives such as lemurs.

"This is the first link to all humans," Hurum, of the Natural History Museum in Oslo, Norway, said in a statement. Ida represents "the closest thing we can get to a direct ancestor."

Ida, properly known as Darwinius masillae, has a unique anatomy. The lemur-like skeleton features primate-like characteristics, including grasping hands, opposable thumbs, clawless digits with nails, and relatively short limbs.

"This specimen looks like a really early fossil monkey that belongs to the group that includes us," said Brian Richmond, a biological anthropologist at George Washington University in Washington, D.C., who was not involved in the study.

Link | Ida’s official website – Thanks Marilyn!

Knowledge on evolution fills many books, which can be intimidating to someone just beginning to learn about it. Geeks are Sexy has a post explaining in layman’s terms how evolution works and the reason why the theory is so important as a tool when examining the world. The basics boil down to four statements:

* Variation, which arises through mutation, exists within and between populations for every trait.
* More individuals are born into a population than can survive (usually because of the scarcity of resources).
* Traits are passed down from parents to their offspring.
* Individuals most fit to survive in their environment generally do (Natural Selection).

Of course, there’s a lot more which is easier to absorb once you have the basics. Link

From the Upcoming ueue, submitted by Geeksaresexy.

Why are snails so slow? Roberto Nespolo and Paulina Artacho of the Southern University of Chile may have the answer: turns out, evolution favors slower snails because they are more energy efficient.

Testing the biological hypothesis of the “energetic definition of fitness,” which purports that the less energy an animal spends, the more it will have for survival and reproduction, the researchers measured the size and standard metabolic rate (the amount of energy required for maintenance) of nearly 100 garden snails. After seven months, the researchers found that surviving snails had a metabolic rate 20 percent lower than that of the dead snails—and no correlation between snail size and rate of survival.

Link

From the Upcoming ueue, submitted by philosophile.

Link

From the Upcoming ueue, submitted by Andrea.

… scientists have discovered that the "rosada" – or pink – iguana is a species in its own right after comparing its genes with other land iguanas on the Galapagos.

There were also physical differences, besides the striking pink and black-striped colouring. Pink iguanas had flat head scales, unlike other land iguanas, and a thick fatty crest on the back of the neck with small conical scales.

Link

Everyone knows about Charles Darwin and his theory of natural selection, but did you know that he once ate an owl, just for kicks? Or that he almost didn't make it aboard HMS Beagle because of the shape of his nose? Behold Neatorama's 10 Fun Facts About Charles Darwin:

1. Darwin Once Ate an Owl

Darwin was an inquisitive man. Sure he was curious about nature and all that science stuff, but he's also a guy. So when he saw strange animals, he often wondered what they would taste like. The difference between Darwin and the rest of us is that he actually ate 'em!

While he was at Cambridge University, Darwin joined the "Gourmet Club," which met once a week to eat animals not often found in menus, like hawk and bittern (a type of wading bird in the heron family). His zeal for weird food, however, broke down when he tried an old brown owl, which he found "indescribable."

But that one episode didn't end Darwin's weird gastronomic proclivities. During the voyage of the Beagle, he ate armadillos and agoutis (the rodents were "best meat I ever tasted," he said).

In Patagonia, South America, Darwin ate a puma (it tasted like veal) and an ostrich-like bird called a Rhea. Actually, Darwin had been looking for this particular species of Rhea, only to find that he had been eating one all along. He sent back the uneaten parts to the Zoological Society in London, which named the bird Rhea darwinii after him!

In the Galapagos, Darwin ate iguanas and giant tortoises. He liked it so much he loaded up 48 of them aboard the Beagle, to be eaten on the journey back!

Sources: Darwin's Dinner at Quite Interesting | The Life and Letters of Charles Darwin by Charles and Francis Darwin

2. Darwin Wanted to Be a Doctor, But He Couldn't Stand the Sight of Blood

Darwin attended Edinburgh University in hopes of becoming a physician like his father, but soon abandoned the idea because he couldn't stand the sight of blood. So he decided to study divinity instead and become a rural cleric, which would fit his hobby of being a naturalist just fine (Source).

3. Darwin's Nose Almost Cost Him The Voyage on the Beagle

The Captain of HMS Beagle, Robert FitzRoy, was about to embark on a survey expedition to South America, but he was afraid of the stress and loneliness of such a voyage (indeed, they have driven the previous captain of the ship to commit suicide). So FitzRoy asked his superiors for a well-educated and scientific gentleman companion to come along as an unpaid naturalist whom he could treat as an equal. The professors at Cambridge recommended then 22-years old Charles Darwin for the trip.

At first, Charles' father Robert objected to the appointment - after all, such a voyage would take years and would get in the way of him being a clergyman. But Darwin's uncle was able to persuade him not only to let his son go, but also support him financially.

Darwin and FitzRoy got together well, but later Darwin found out that he almost didn't get picked for the voyage ... on account of the shape of his nose!

"Afterwards on becoming very intimate with Fitz-Roy, I heard that I had run a very narrow risk of being rejected [as the Beagle's naturalist], on account of the shape of my nose! He was an ardent desciple of Lavater, and was convinced that he could judge a man's character by the outline of his features; and he doubted wheather anyone with my nose could possess sufficient energy and determination for the voyage. But I think he was afterwards well-satisfied that my nose had spoken falsely." (Source: Charles Darwin: His Life Told in an Autobiographical Chapter, and in a Selected Series of His Published Letters, by Charles Darwin - 1902)

4. Best Birthday Gift Ever: a Mountain!

Mount Darwin in Tierra del Fuego, Photo: Victory Adventure Expeditions

For Darwin's 25th birthday on February 12, 1834, Captain FitzRoy named a mountain after him. Yup, Mount Darwin. It is the highest peak in Tierra del Fuego.

A year earlier, Darwin and his shipmates were on a small island in the Tierra del Fuego archipelago when a huge mass of ice fell from the face of a glacier and plunged into the ocean, causing a huge wave. Darwin ran to the shore and saved the ship's boats from being swept away. For saving everyone from being marooned, FitzRoy named the area Darwin Sound.

And as if one mountain isn't enough, Darwin got three more named after him: There are other Darwin Mountains located in California, Tasmania, and Antarctica.

5. The Full Title of "On The Origin of Species"

Larger photo: University of Sydney

You probably know that Darwin's most famous work, outlining his theory of evolution, is On the Origin of Species.

But what most people don't know is the full title: On the Origin of Species by means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. It was published in 1859, twenty years after his epic voyage (yes, he took his sweet time in publishing his work, which he only did because Alfred Russell Wallace came to the same conclusion of evolution and Darwin didn't want to be left behind). A total of 1250 copies were printed and it went on sale for 15 shillings. It's now valued at around $23,000.

In the 6th edition, the title was changed to The Origin of Species.

6. Darwin Didn't Invent the Phrase "Survival of the Fittest"

That was Herbert Spencer, a philosopher and contemporary of Charles Darwin. After reading Darwin's On the Origin of Species, Spencer wrote Principles of Biology in 1864. He coined the phrase "survival of the fittest" and extended Darwin's theory of natural selection into the realm of sociology, ethics, and economics.

Darwin himself used the phrase in his 5th edition of The Origin and gave full credit to Spencer.

7. Darwin Married His First Cousin

Darwin was a logical man, and he approached the important issue of marriage like he would any problem. In The Correspondence of Charles Darwin, Darwin made careful pro and con list of marriage to his first cousin, Emma Wedgwood:

Image: Cambridge University Library - The Complete Work of Charles Darwin Online

Under the title "This is the Question," Darwin wrote in the "Marry" Column:

Children — (if it Please God) — Constant companion, (& friend in old age) who will feel interested in one, — object to be beloved & played with. — —better than a dog anyhow. — Home, & someone to take care of house — Charms of music & female chit-chat. — These things good for one's health. — Forced to visit & receive relations but terrible loss of time. —

W My God, it is intolerable to think of spending ones whole life, like a neuter bee, working, working, & nothing after all. — No, no won't do. — Imagine living all one's day solitarily in smoky dirty London House. — Only picture to yourself a nice soft wife on a sofa with good fire, & books & music perhaps — Compare this vision with the dingy reality of Grt. Marlbro' St.

... and in the "Not Marry" column:

No children, (no second life), no one to care for one in old age.— What is the use of working 'in' without sympathy from near & dear friends—who are near & dear friends to the old, except relatives

Freedom to go where one liked — choice of Society & little of it. — Conversation of clever men at clubs — Not forced to visit relatives, & to bend in every trifle. — to have the expense & anxiety of children — perhaps quarelling — Loss of time. — cannot read in the Evenings — fatness & idleness — Anxiety & responsibility — less money for books &c — if many children forced to gain one's bread. — (But then it is very bad for ones health to work too much)

Perhaps my wife wont like London; then the sentence is banishment & degradation into indolent, idle fool —

He concluded that he should marry, and wrote:

Marry - Marry - Marry Q.E.D.

It is ironic that the man who gave rise to the importance of genetics in natural selection chose to marry his first cousin (Darwin wasn't alone in this - Einstein also married his cousin), but one thing is for sure: Darwin cleverly avoided adding more relatives to visit!

8. How Darwin Lost His Faith in Christianity

Darwin was actually quite a religious fellow when he began his voyage on the Beagle (he was fresh out of divinity school). Aboard the ship, Darwin was known to quote passages from the bible to rowdy sailors on board.

But something happened during the trip that made him less religious. Darwin saw slavery firsthand as well as the wretched living conditions of the natives of Tierra del Fuego and wondered why God allowed such inhumanities to happen (Source). Darwin became skeptical of the history in the Old Testament, yet still believed in the existence of God.

Darwin lost his faith when his daughter Annie caught scarlet fever and died at the age of 10. He wrote "We have lost the joy of the household, and the solace of our old age ... Oh that she could now know how deeply, how tenderly we do still & and shall ever love her dear joyous face." The heartsick Emma filled a small box with Annie's small treasures and kept it until her own death. (Source)

From then on, Darwin continued to help the local church with parish work, but would go on walks while his family attended church on Sundays. When asked about his religious views, Darwin denied that he was an atheist, but called himself agnostic.

In 1915, Lady Hope claimed to have visited Darwin and witnessed his deathbed conversion back to Christianity. This was refuted by his children, who noted that his last words were to Emma: "I am not the least afraid of death - Remember what a good wife you have been - Tell all my children to remember how good they have been to me." (Source)

9. Darwin was a Backgammon Fiend

After his return from South America, Darwin developed a life-long illness that left him severely debilitated or bed-ridden for long periods of time. Darwin consulted with more than 20 doctors, but the cause of his disease was never discovered (Wikipedia has a n interesting list of possible illnesses).

Over the years, with the help of Emma, Darwin developed a strict routine that seemed to help in alleviating the symptoms. AboutDarwin.com has an interesting glimpse into what everyday life was like for Darwin.

Of note is Darwin's strict schedule for playing backgammon. Every night between 8 and 8:30 PM, Darwin would play 2 games of backgammon with Emma. He even kept score of every game he played for years!

10. Church of England Finally Apologized to Darwin

When Darwin's work on the theory of evolution came out, the church attacked him vociferously. Now, 126 years after his death, The Church of England has apologized to Darwin:

Charles Darwin: 200 years from your birth, the Church of England owes you an apology for misunderstanding you and, by getting our first reaction wrong, encouraging others to misunderstand you still. We try to practice the old virtues of 'faith seeking understanding' and hope that makes some amends. But the struggle for your reputation is not over yet, and the problem is not just your religious opponents but those who falsely claim you in support of their own interests. Good religion needs to work constructively with good science – and I dare to suggest that the opposite may be true as well. (Source)

If you like this article, you'll probably love these 10 Fun Facts articles on Neatorama:

• 10 Strange Facts About Einstein
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• 10 Neat Facts About ... Rick Astley!
• 10 Fascinating Facts about Edison
• 10 Kick Ass Facts About Bruce Lee
• 10 Strange Facts About Newton