Human shoulders evolved to throw, as this infographic explains:
H.P. Lovecraft was obviously not a dog guy:
I have no active dislike for dogs, any more than I have for monkeys, human beings, negroes, cows, sheep, or pterodactyls; but for the cat I have entertained a particular respect and affection ever since the earliest days of my infancy. In its flawless grace and superior self-sufficiency I have seen a symbol of the perfect beauty and bland impersonality of the universe itself, objectively considered; and in its air of silent mystery there resides for me all the wonder and fascination of the unknown. The dog appeals to cheap and facile emotions; the cat to the deepest founts of imagination and cosmic perception in the human mind. It is no accident that the contemplative Egyptians, together with such later poetic spirits as Poe, Gautier, Baudelaire, and Swinburne, were all sincere worshippers of the supple grimalkin.
Goodwell Nzou, a doctoral student in molecular and cellular biosciences at Wake Forest University explains, in Zimbabwe, they don’t cry for lions:
When I turned on the news and discovered that the [Facebook] messages [about Cecil] were about a lion killed by an American dentist, the village boy inside me instinctively cheered: One lion fewer to menace families like mine.
My excitement was doused when I realized that the lion killer was being painted as the villain. I faced the starkest cultural contradiction I’d experienced during my five years studying in the United States.
Did all those Americans signing petitions understand that lions actually kill people? That all the talk about Cecil being “beloved” or a “local favorite” was media hype? Did Jimmy Kimmel choke up because Cecil was murdered or because he confused him with Simba from “The Lion King”?
In my village in Zimbabwe, surrounded by wildlife conservation areas, no lion has ever been beloved, or granted an affectionate nickname. They are objects of terror.
When I was 9 years old, a solitary lion prowled villages near my home. After it killed a few chickens, some goats and finally a cow, we were warned to walk to school in groups and stop playing outside. My sisters no longer went alone to the river to collect water or wash dishes; my mother waited for my father and older brothers, armed with machetes, axes and spears, to escort her into the bush to collect firewood.
A week later, my mother gathered me with nine of my siblings to explain that her uncle had been attacked but escaped with nothing more than an injured leg. The lion sucked the life out of the village: No one socialized by fires at night; no one dared stroll over to a neighbor’s homestead.
When the lion was finally killed, no one cared whether its murderer was a local person or a white trophy hunter, whether it was poached or killed legally. We danced and sang about the vanquishing of the fearsome beast and our escape from serious harm.
Recently, a 14-year-old boy in a village not far from mine wasn’t so lucky. Sleeping in his family’s fields, as villagers do to protect crops from the hippos, buffalo and elephants that trample them, he was mauled by a lion and died.
The killing of Cecil hasn’t garnered much more sympathy from urban Zimbabweans, although they live with no such danger. Few have ever seen a lion, since game drives are a luxury residents of a country with an average monthly income below $150 cannot afford.
Don’t misunderstand me: For Zimbabweans, wild animals have near-mystical significance. We belong to clans, and each clan claims an animal totem as its mythological ancestor. Mine is Nzou, elephant, and by tradition, I can’t eat elephant meat; it would be akin to eating a relative’s flesh. But our respect for these animals has never kept us from hunting them or allowing them to be hunted. (I’m familiar with dangerous animals; I lost my right leg to a snakebite when I was 11.)
The American tendency to romanticize animals that have been given actual names and to jump onto a hashtag train has turned an ordinary situation — there were 800 lions legally killed over a decade by well-heeled foreigners who shelled out serious money to prove their prowess — into what seems to my Zimbabwean eyes an absurdist circus.
PETA is calling for the hunter to be hanged. Zimbabwean politicians are accusing the United States of staging Cecil’s killing as a “ploy” to make our country look bad. And Americans who can’t find Zimbabwe on a map are applauding the nation’s demand for the extradition of the dentist, unaware that a baby elephant was reportedly slaughtered for our president’s most recent birthday banquet.
To introduce this mutation in pigs, Kim used a gene-editing technology called a TALEN, which consists of a DNA-cutting enzyme attached to a DNA-binding protein. The protein guides the cutting enzyme to a specific gene inside cells, in this case in MSTN, which it then cuts. The cell’s natural repair system stitches the DNA back together, but some base pairs are often deleted or added in the process, rendering the gene dysfunctional.
The team edited pig fetal cells. After selecting one edited cell in which TALEN had knocked out both copies of the MSTN gene, Kim’s collaborator Xi-jun Yin, an animal-cloning researcher at Yanbian University in Yanji, China, transferred it to an egg cell, and created 32 cloned piglets.
Yin says that preliminary investigations, show that the pigs provide many of the double-muscled cow’s benefits — such as leaner meat and a higher yield of meat per animal. However, they also share some of its problems. Birthing difficulties result from the piglets’ large size, for instance. And only 13 of the 32 lived to 8 months old. Of these, two are still alive, says Yin, and only one is considered healthy.
Rather than trying to create meat from such pigs, Kim and Yin plan to use them to supply sperm that would be sold to farmers for breeding with normal pigs. The resulting offspring, with one disrupted MSTN gene and one normal one, would be healthier, albeit less muscly, they say; the team is now doing the same experiment with another, newer gene-editing technology called CRISPR/Cas9. Last September, researchers reported using a different method of gene editing to develop new breeds of double-muscled cows and double-muscled sheep (C. Proudfoot et al. Transg. Res. 24, 147–153; 2015).
Off the coast of Louisiana, 2,000 feet down, a remotely operated vehicle had a curious visitor. Watch — and listen to the monitoring scientists geek out:
When birds squawk, other species listen:
Studies in recent years by many researchers, including Dr. Greene, have shown that animals such as birds, mammals and even fish recognize the alarm signals of other species. Some can even eavesdrop on one another across classes. Red-breasted nuthatches listen to chickadees. Dozens of birds listen to tufted titmice, who act like the forest’s crossing guards. Squirrels and chipmunks eavesdrop on birds, sometimes adding their own thoughts. In Africa, vervet monkeys recognize predator alarm calls by superb starlings.
So-called “seet” calls, peeps produced by many small songbirds in response to a raptor on the wing, are well-known to ornithologists. Conventional wisdom held that the calls dissipated quickly and were produced only for other birds nearby. However, that’s not what Dr. Greene noticed: chatter sweeping across the hillside, then birds diving into bushes.
Studying the phenomenon, he documented a “distant early-warning system” among the birds in which the alarm calls were picked up by other birds and passed through the forest at more than 100 miles per hour. Dr. Greene likened it to a bucket brigade at a fire.
The information rippled ahead of a predator minutes before it flew overhead, giving prey time to hide. Moreover, while raptors can hear well at low frequencies, they are not very good at hearing at 6 to 10 kilohertz, the higher frequency at which seet calls are produced. “So it’s sort of a private channel,” he said.
Dr. Greene turned to chickadees, which are highly attuned to threats. When one sees a perched raptor nearby, it will issue its well-known “chick-a-dee” call, a loud, frequent and harsh sound known as a mobbing call because its goal is to attract other birds to harass the predator until it departs.
In 2005, Dr. Greene was an author of an article in the journal Science that demonstrated how black-capped chickadees embed information about the size of predators into these calls. When faced with a high-threat raptor perched nearby, the birds not only call more frequently, they also attach more dee’s to their call.
Raptors tend to be the biggest threat to birds nearest their own size because they can match the maneuverability of their prey. So a large goshawk might only merit a chick-a-dee-dee from a nimble chickadee, while that little pygmy owl will elicit a chick-a-dee followed by five or even 10 or 12 additional dee syllables, Dr. Greene said.
The researchers next showed that red-breasted nuthatches, which are chickadee-size and frequently flock with them in the winter, eavesdrop on their alarm language, too.
Dr. Greene, working with a student, has also found that “squirrels understand ‘bird-ese,’ and birds understand ‘squirrel-ese.’ ” When red squirrels hear a call announcing a dangerous raptor in the air, or they see such a raptor, they will give calls that are acoustically “almost identical” to the birds, Dr. Greene said. (Researchers have found that eastern chipmunks are attuned to mobbing calls by the eastern tufted titmouse, a cousin of the chickadee.)
A Texas hunter bid $350,000 for the right to hunt a rhino in Namibia:
Knowlton’s $350,000 will go to fund government anti-poaching efforts across the country. And the killing of an older rhino bull, which no longer contributes to the gene pool but which could harm or kill younger males, is part of the science of conservation, he argues.
Naturally, this makes him a terrible person:
“I think people have a problem just with the fact that I like to hunt,” Knowlton said. “I want to see the black rhino as abundant as it can be. I believe in the survival of the species.”
Australian rainbow lorikeets eat nectar and pollen — and meat:
For years, Bill, who owns the Elimbah property, has put out pets mince for magpies, currawongs and kookaburras.
He also puts out seed for vegetarian birds like galahs, king parrots and the lorikeets.
He feeds about a dozen birds each day and knows they are spoilt for choice when it comes to food.
Bill’s property is home to native trees and shrubs, and there is untouched forest nearby.
He is happy to offer a few scoops of mince and seed to the birds that come in for a free feed.
It was about seven years ago when Bill first noticed the lorikeets eating meat, and they have been eating it ever since.
“At first they went for the seed but then they started chasing the other birds away from the meat, which surprised me,” he said.
Professor Jones said the availability of food on the property made the lorikeet’s decision to eat meat mystifying.
Altered neural crest development could be the reason mammals change in oddly consistent ways during domestication:
As first noted by Darwin more than 140 years ago, domestic mammals tend to share certain characteristics—a suite of traits called the domestication syndrome.
The syndrome includes increased docility and tameness, coat color changes, reductions in tooth size, changes in craniofacial morphology, alterations in ear and tail form, more frequent and nonseasonal estrus cycles, alterations in hormone levels, changed concentrations of neurotransmitters, prolonged juvenile behavior, and reduced forebrain size.
Wilkins and Wrangham set about listing these mysterious marks of domestication and trying to match them to tissues affected by the neural crest. Within half an hour they decided that neural crest changes could plausibly account for most of the syndrome’s traits.
The neural crest hypothesis builds on observations from the long-running fox domestication experiments started in 1959 in Novosibirsk, Siberia, by Dmitri Belyaev:
After generations of selection purely for tameness, Novosibirsk foxes today show not only a friendly, people-loving disposition reminiscent of dogs, but also seemingly unrelated traits like curly tails, floppier ears and patches of white fur.
One of the many changes seen in the tame foxes was reduced size and function of their adrenal glands, which release stress hormones during the “fight-or-flight” response. This dampened adrenal function may lie at the heart of the behavioral changes observed in domestication syndrome. Wilkins et al. argue that one way to end up with smaller adrenal glands is via mild deficits of the neural crest.
The neural crest is a cell population that pinches off from the edge of the developing neural tube duing early embryogenesis. These cells migrate to many parts of the body and form the precursors of a plethora of tissue types, including pigment cells, parts of the skull, larynx, ears, teeth, sympathetic nervous system, and, of course, parts of the adrenal glands. So subtle changes in neural crest cell numbers, migration, or proliferation would lead to widespread phenotypic effects.
Wilkins et al. argue that their ideas dovetail with certain effects of human neural crest cell disorders, like the patches of depigmented skin and hair seen in Waardenburg syndrome or the jaw, ear and teeth phenotypes of Treacher Collins syndrome.
And even though neural crest cells don’t directly develop into the central nervous system, they could still partly explain why many domestic mammals have smaller forebrains than their wild ancestors. Experiments in chick embryos suggest that signals from neural crest cells play a crucial role in forebrain development. At this stage, not every component of the domestication syndrome can be firmly tied into the hypothesis. For example, the curly tails of dogs, pigs, and domestic foxes don’t have an obvious connection to neural crest deficits. Nonetheless, the authors believe enough links exist to warrant experimental tests of their predictions.
Female orcas (killer whales) live into their nineties, even though they typically stop breeding at 40. Males only live to 50:
The only other species known to go through a menopause and live so long without reproducing are humans and short-finned pilot whales.
Croft and colleagues watched 750 hours of video of orca family pods. Over 100 individually recognisable orcas were filmed in the coastal Pacific waters off British Columbia and Washington since 1976.
The team found that post-menopausal females were 32 and 57 per cent more likely than non-menopausal adult females or adult males respectively to lead the group. They were also significantly more likely to lead the group in years when their staple food – chinook salmon – was in short supply.
“It’s probably accumulated experience,” says Croft. “Anyone who fishes for migratory trout or salmon will tell you that timing is key, that the fish return in particular cycles of tides and times of the year. Post-menopausal females probably get to know where to look and when.”
In most known animal species, males rapidly leave their parents, becoming completely independent. Male and female orcas, by contrast, stay in a family unit for life, with the males occasionally exchanging pods temporarily to breed. The upshot, says Croft, is that if females survive for many decades, breeding for the first three or four, their pod becomes increasingly replete with their descendants. Therefore, it becomes more and more in their own interests to safeguard the survival of the pod, and thereby their own genetic legacy.
“There’s a tipping point where they stop reproducing and help their offspring instead, as do grandmothers in the human context,” says Croft.
The findings seem to support the “grandmother hypothesis”, the idea that older women in hunter-gatherer communities evolved to go through the menopause so that they could carry on passing on their wisdom and experience about food sources and other survival tips without the added costs of having more children themselves.
Modern humans formed an alliance with wolves soon after entering Europe:
We tamed some and the dogs we bred from them were then used to chase prey and to drive off rival carnivores, including lions and leopards, that tried to steal the meat.
“Early wolf-dogs would have tracked and harassed animals like elk and bison and would have hounded them until they tired,” said Shipman. “Then humans would have killed them with spears or bows and arrows.
“This meant the dogs did not need to approach these large cornered animals to finish them off — often the most dangerous part of a hunt — while humans didn’t have to expend energy in tracking and wearing down prey. Dogs would have done that. Then we shared the meat. It was a win-win situation.”
At that time, the European landscape was dominated by mammoths, rhinos, bison and several other large herbivores. Both Neanderthals and modern humans hunted them with spears and possibly bows and arrows. It would have been a tricky business made worse by competition from lions, leopards, hyenas, and other carnivores, including wolves.
“Even if you brought down a bison, within minutes other carnivores would have been lining up to attack you and steal your prey,” said Shipman. The answer, she argues, was the creation of the human-wolf alliance. Previously they separately hunted the same creatures, with mixed results. Once they joined forces, they dominated the food chain in prehistoric Europe — though this success came at a price for other species. First Neanderthals disappeared to be followed by lions, mammoths, hyenas and bison over the succeeding millennia. Humans and hunting dogs were, and still are, a deadly combination, says Shipman.
Humans slowly changed wolves into dogs, but humans may have changed to:
Consider the whites of our eyes, she states. The wolf possesses white sclera as does Homo sapiens though, crucially, it is the only primate that has them.
“The main advantage of having white sclera is that it is very easy to work out what another person is gazing at,” added Shipman. “It provides a very useful form of non-verbal communication and would have been of immense help to early hunters. They would been able to communicate silently but very effectively.”
Thus the mutation conferring white sclera could have become increasingly common among modern humans 40,000 years ago and would have conferred an advantage on those who were hunting with dogs.
(Hat tip to HBD Chick.)
Once, in ancient times, the Middle East teemed with carts and wagons and chariots, but they were totally driven out by the coming of the camel:
Good harnesses for camels were designed in Central Asia and, in the 19th century, in the Australian desert, but these did not affect the Middle East.
The only way to make use of this immensely strong beast for transport was to throw the load, averaging anywhere from 300 to 500 pounds, on its back. Thus the pack camel came to compete directly with the ox cart for heavy transport.
The ox cart was equally slow, and in the competition the camel had certain positive advantages. It ate otherwise unusable desert plants, which made its upkeep inexpensive. Little wood, a valuable commodity in the largely deforested Middle East, was required by ancient saddling technology. And its care and breeding could be left to the nomads and thus not be a burden upon the farmer or merchant.
These advantages meant that camel transport was about 20 percent cheaper than wagon transport, according to the edict on prices issued by the Roman emperor Diocletian in the third century A.D. Therefore, simple economic efficiency caused the camel to supplant the wheel, not some mysterious reversion to primitive life.
(Hat tip to commenter Harold!)
I can still remember some grad students at a party years ago describing what their friends in the biology department had found while doing field work on birds, which they had to temporarily snare to study:
When researchers in North Dakota set up “nest cams” over the nests of song birds, they expected to see a lot of nestlings and eggs get taken by ground squirrels, foxes, and badgers. Squirrels hit thirteen nests, but other meat-eaters made a poor showing. Foxes and weasels only took one nest each. Know what fearsome animal out-did either of those two sleek, resourceful predators?
These supposed herbivores placidly ate living nestlings right out of the nest. And if you’re thinking that it must be a mistake, that the deer were chewing their way through some vegetation and happened to get a mouthful of bird, think again. Up in Canada, a group of ornithologists were studying adult birds. In order to examine them closely, the researchers used “mist-nets.” These nets, usually draped between trees, are designed to trap birds or bats gently so they could be collected, studied, and released. When a herd of deer came by, they deer walked up to the struggling birds and ate them alive, right out of the nets.
This behavior is not limited to one species or one continent. Last year, a farmer in India made a video of a cow eating a recently-hatched chick. Some scientists speculate that herbivores turn to meat when they’re not getting enough nutrients in their diet. It’s possible. A biologist in Scotland documented red deer eating seabird chicks, and concluded it was how they got the dietary boost necessary to grow their antlers. The same researcher also documented sheep eating the heads and legs off of seabird chicks. And then there’s another cow in India, which reportedly ate fifty chickens. There may be a specific need that drives herbivores to occasionally eat meat. It’s also possible, experts say, that eating meat, when it can’t run away from them, is just something supposed “herbivores” do, and we’re finally getting wise to it.
While on a shark-cage diving trip to the Neptune Islands off the coast of Australia, charter operator Matt Waller witnessed killer whales launching themselves out of the water and slamming down on a great white shark:
“If that’s what we’re seeing on the surface, then I can only imagine that under the surface you had other whales that were working to try and keep this shark up,” he said.
“It never actually went down. It stayed on the surface and was trying to get away.”