Chimpanzee
laelaps | April 6, 2010
A leopard (Panthera pardus). Image from Wikipedia.
SK-54 is a curious fossil. The 1.5 million year old skullcap represents a juvenile Paranthropus robustus, one of the heavy-jawed hominins which lived in prehistoric South Africa, but there is something that makes this skull fragment particularly special. Near one of the sutures along the back of the skull are two neat puncture marks, the hallmark of a leopard.
Even though it was initially proposed that SK-54 had been murdered by another australopithecine wielding a weapon of bone or horn, in the late 1960's the paleontologist C.K. Brain…
laelaps | March 1, 2010
An adult chimpanzee in Bossou, Guinea uses hammer and anvil stones to crack nuts as younger individuals look on. From Haslam et al., 2009.
Before 1859 the idea that humans lived alongside the mammoths, ground sloths, and saber-toothed cats of the not-too-distant past was almost heretical. Not only was there no irrefutable evidence that our species stretched so far back in time, but the very notion that we could have survived alongside such imposing Pleistocene mammals strained credulity. Contrary to what might be immediately expected, however, it was not Darwin's famous abstract On the…
edyong | January 13, 2010
Men who think that size really matters should probably not think too hard about the Y chromosome. This bundle of genes is the ultimate determinant of manliness, and it happens to be a degenerate runt. Over a few hundred million years, it has shrunk considerably, jettisoning around 97% of its original genes. Where it was once a large library of genes, now it's more a struggling independent bookstore. This loss of information defined the youth of the Y chromosome but nowadays, things are different. Renovation is the order of the day.
Jennifer Hughes from MIT revealed the recent history of…
razib | August 30, 2009Thomas Mailmund is going ape over chimps & humans again, Patterns of autosomal divergence between the human and chimpanzee genomes support an allopatric model of speciation. A review of a paper of the same name.
razib | August 20, 2009Thomas Mailund on Doubts about complex speciation between humans and chimpanzees:
Two patterns from large-scale DNA sequence data have been put forward as evidence that speciation between humans and chimpanzees was complex, involving hybridization and strong selection. First, divergence between humans and chimpanzees varies considerably across the autosomes. Second, divergence between humans and chimpanzees (but not gorillas) is markedly lower on the X chromosome. Here, we describe how simple speciation and neutral molecular evolution explain both patterns. In particular, the wide range in…
emjohnson | August 17, 2009Benjamin Franklin once quipped, "Where there's marriage without love there will be love without marriage." His affairs are well known in American history, however this founding father may have been stating a truth extending to evolutionary history as well.
Christopher Ryan (author of the forthcoming Sex at Dawn) offers some thoughts on the role of novelty in the sex lives of our favorite primate. He suggests that men are drawn to variety in sexual partners while women are drawn to variety in technique:
When researchers decided to look at this issue to develop a Sexual Boredom Scale, they…
edyong | June 4, 2009 If you tickle a young chimp, gorilla or orang-utan, it will hoot, holler and pant in a way that would strongly remind you of human laughter. The sounds are very different - chimp laughter, for example, is breathier than ours, faster and bereft of vowel sounds ("ha" or "hee"). Listen to a recording and you wouldn't identify it as laughter - it's more like a handsaw cutting wood.
But in context, the resemblance to human laughter is uncanny. Apes make these noises during play or when tickled, and they're accompanied by distinctive open-mouthed "play faces". Darwin himself noted the laugh-like…
sciencepunk | May 15, 2009Over at the Mental Indigestion blog, Dr Jim teaches us an important lesson in appropriate games to play with greater apes whilst down the pub. Namely, do not challenge a chimp to an arm wrestling match:
As you take up the strain, know that the fine-tuned positioning and slow, steady building of muscle force you exert is due to the greater amount of grey matter that you posses in your spinal cord; motor neuron nerves cells that connect to muscle fibres and regulate muscle movement. The huge surplus of motor neurons you possess allows you to engage smaller portions of your muscles at any given…
edyong | April 8, 2009Many men think of little else besides sex and meat, but male chimpanzees will sometimes exchange one for the other. Chimps are mostly vegetarian but they will occasionally supplement their diet by hunting other animals, especially monkeys. Males do most of the hunting, but they don't eat their spoils alone - often, they will share the fresh meat with females, even those who are unrelated to them. Some scientists have suggested that this apparently selfless act is a trade - the males are giving up their nutritious catch in exchange for sex.
Cristina Gomes and Christophe Boesch from the Max…
edyong | April 5, 2009
For humans, our culture is a massive part of our identity, from the way we dress, speak and cook, to the social norms that govern how we interact with our peers. Our culture stems from our ability to pick up new behaviours through imitation, and we are so innately good at this that we often take it for granted.
We now know that chimpanzees have a similar ability, and like us, different groups have their own distinct cultures and traditions.
Now, Andrew Whiten from the University of St Andrews has published the first evidence that groups of chimpanzees can pick up new traditions from each…
zooillogix | April 2, 2009
by Katie the Lowly Intern
You might recall this gentle soul who got her face gnawed off by a chimp in February. I won't even begin to sift through the big ball of bizarre that story is, but it does lead to an interesting discussion concerning exactly where apes get enough strength to go around mauling humans. Biologists agree that a great ape's muscle structure is better, faster, stronger than our measly muscles. However, Alan Walker, a professor of Biology at Penn State just published an article in Current Anthropology that looks at another possible contributing factor.
He makes the…
edyong | March 24, 2009Be it in sports or comedy, they say that timing is everything. In evolution, it's no different. Many of the innovations that have separated us from other apes may have arisen not through creating new genetic material, but by subtly shifting how the existing lot is used.
Take our brains, for example. In the brains of humans, chimps and many other mammals, the genes that are switched on in the brain change dramatically in the first few years of life. But Mehmet Somel from the Max Planck Institute for Evolutionary Anthropology has found that a small but select squad of genes, involved in the…
edyong | March 9, 2009
In 1997, Swedish inspectors found several stockpiles of missiles hidden in a local zoo. Apparently, the arsenal had been gathered together for the express purpose of being used against civilians. And who was the mastermind behind this collection? A 19-year-old chimpanzee called Santino.
Santino was born in a German zoo in 1978 and transferred to Furuvik Zoo at the age of 5. To this day, he lives in the zoo's chimpanzee island - a large outdoor enclosure surrounded by a moat. Throughout his residence, he was mostly docile towards the eager visitors, but all of that changed in 1997 when he…
sheril | March 4, 2009Guest post by Brian Hare, Evolutionary Anthropologist at Duke University
Last month, a 200 pound male chimpanzee named Travis mauled a woman outside the home where he has been living with his owner Sandra Herold. Charla Nash was nearly killed by Travis and now has life changing wounds to her face while Travis was stabbed by his owner with a butcher knife and shot dead by the police.
Was this incidence preventable or just a freak accident? Should chimpanzees and other primates be kept as pets? What is the effect of the primate pet trade not only on the welfare of these "pets" but on their…
edyong | March 3, 2009In the Goualougo Triangle of the Republic of Congo, a chimpanzee is hungry for termites. Its prey lives within fortress-like nests, but the chimp knows how to infiltrate these. It plucks the stem from a nearby arrowroot plant and clips any leaves away with its teeth, leaving behind a trimmed, flexible stick that it uses to "fish" for termites.
Many chimps throughout Africa have learned to build these fishing-sticks. They insert them into termite nests as bait, and pull out any soldier termites that bite onto it. But the Goualougo chimps do something special. They deliberately fray the ends…
gregladen | February 24, 2009Is chimpanzee food sharing an example of food for sex?
One of the most important transitions in human evolution may have been the incorporation of regular food sharing into the day to day ecology of our species or our ancestors. Although this has been recognized as potentially significant for some time, it was probably the Africanist archaeologist Glynn Isaac who impressed on the academic community the importance of the origins of food sharing as a key evolutionary moment. At that time, food sharing among apes was thought to be very rare, outside of mother-infant dyads. Further research…
gregladen | February 23, 2009My student, Marta, exploded the other day.
She was sitting there in class two weeks ago and exploded. She does not know that I know this, but I noticed it happen. Since she was sitting, as usual, in the front row, and it was all in her face, the other students did not see it but I definitely did.
By "exploding" in this case I mean that her brain suddenly filled with unanswered questions, which she then started sending me in frantic emails. Many of these questions are about things we will eventually get to in class, but some are on issues that we won't touch on at all. I decided, and I…
razib | February 19, 2009Sheril's post, Chimpanzees Are NOT Pets!, is good. She notes:
1 Chimpanzees are wild animals. Animals that make good PETS like dogs and cats, have been domesticated for [thousands] of years. There has been selection on them against aggression, which is why a dog, unlike a wolf, will not automatically tear you to pieces. Anyone who has a pet chimpanzee for long enough will eventually no longer be able to control them and will either get a body part bitten off or will have to use extreme force to control them. Chimps live to be 50 years old and grow almost as big as a human male. They have…
sheril | February 18, 2009You've likely already seen this story all over the news:
Chimp's owner calls vicious mauling 'freak thing'
STAMFORD, Conn. (AP) -- The owner of a 200-pound chimpanzee that viciously mauled a Stamford woman calls the incident "a freak thing," but says her pet was not a "horrible" animal.
Sandra Herold told NBC's "Today Show" in an interview aired Wednesday that Travis, her 14-year-old chimpanzee, was like a son to her.
Herold tried to save her friend by stabbing the chimp with a butcher knife and bludgeoning it with a shovel.
I have extremely strong emotions concerning this particular issue…