Primates
laelaps | April 7, 2010Want the dirt on the new species of fossil human which will be described in Science this week? Tune in to the BBC World Service "Science in Action" program this Friday to hear me discuss the discovery with host Jon Stewart. The program should be available on the web sometime after it airs, as well.
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 | April 5, 2010According to multiple reports released yesterday, scientists will announce the discovery of a new species of two-million-year-old hominin this week. Do you know what that means? That's right; writers are breaking out the pop-sci boilerplate to tell us all about the new "missing link." To paraphrase what I have seen in the headlines alone, the find is the "missing link which will shed new light on human evolution and rewrite what we thought we knew about our history."
I don't believe the hype, but I can only speculate on the actual significance of the specimens in question. According to the…
laelaps | April 2, 2010
A margay (Leopardus wiedii). From Wikipedia.
Even if they spend years in the field, researchers rarely witness predation on primates. Cats, birds, and other hunters regularly feed on primate species, but what we know about the habits of primate-hunters often comes from bones and fingernails picked out of predator droppings. Every now and again, though, someone is in just the right place at just the right time to observe a predator attempt to catch a primate for dinner, and one recent observation in the Amazon has revealed an ingenious hunting technique employed by a small spotted cat.…
laelaps | April 1, 2010
The partial faces of Anoiapithecus (left), Pierolapithecus (center), and Dryopithecus (right). (Images not to scale)
Our species is just one branch of a withering part of the evolutionary tree, the great apes. Along with the handful of species of chimpanzees, gorillas, and orangutans, we are all that is left of the hominids, and considering the threats our close relatives face we could very soon be the only great apes left. It has not always been this way. During the swath of prehistory ~23-5 million years ago known as the Miocene a variety of ape species inhabited forests through much of…
laelaps | March 31, 2010
A grey mouse lemur (Microcebus murinus). Image from Wikipedia.
Charles Darwin's visit to the Galapagos Archipelago has been celebrated time and again for its influence on his evolutionary thoughts, but I have to wonder what would have happened if the Beagle skipped the Galapagos and visited Madagascar instead. What would Darwin have made of the animals which had been evolving in splendid isolation on the African island? Would "Darwin's lemurs", rather than Darwin's finches, be among the most recognizable icons of evolution?
Answers to such questions are beyond our grasp, but the diverse…
laelaps | March 23, 2010
A comparison of three-dimensional scans of hominin footprints. Top) A footprint made by an experimental subject using a normal, "extended" gait. Middle) A footprint made by an experimental subject using a "bent-knee, bent-hip" gait. Bottom) A Laetoli footprints. From Raichlen et al., 2010.
About 3.6 million years ago, at a spot now in Laetoli, Tanzania, a pair of hominins trudged through the ashfall dumped onto the landscape by a nearby volcano. We don't know for certain what they looked like (it is generally believed that they were Australopithecus afarensis from the presence of fossils…
laelaps | March 9, 2010
A simplified evolutionary tree of primate relationships showing the placement of Darwinius in relationship to other groups. From Williams et al., 2010.
The study of human origins can be a paradoxical thing. We know that we evolved from ancestral apes (and, in fact, are just one peculiar kind of ape), yet we are obsessed with the features that distinguish us from our close relatives. The "big questions" in evolutionary anthropology, from why we stand upright to how our brains became so large, are all centered around distancing us from a prehistoric ape baseline. Despite our preoccupation…
laelaps | March 3, 2010
The exceptionally preserved skeleton of Darwinius, known popularly as "Ida." From PLoS One.
Almost ten months ago an international team of researchers introduced the world to an exquisitely-preserved primate from the 47 million year old oil shales of Messel, Germany. Dubbed Darwinius masillae, and nicknamed "Ida" and "The Link", the fossil was touted as one of our earliest primate ancestors in a massive media campaign worthy of a Hollywood blockbuster. Yet the trouble was that there was no solid evidence that Darwinius was one of our ancestors. Despite the marketing blitz promoting the…
laelaps | March 2, 2010
A young Japanese macaque (Macaca fuscata), photographed at the Central Park Zoo.
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…
laelaps | February 27, 2010
Male (right) and female (left, with infant) friends in a population of Chacma baboons. (From Palombit, 2009).
Among other things, friends are people you count on to come to your aid when you need help. If you were at a bar and a stranger started acting aggressively towards you, for example, you would expect your friends to rush over to help you rather than just stand there, mojito in hand. Contrary to our feelings of human exceptionalism, however, ours is not the only species of primate to create and maintain friendships.
For years primatologists have been puzzling over "friendship" in…
laelaps | February 21, 2010
A Coquerel's sifaka (Propithecus coquereli), photographed at the Bronx Zoo.
milhayser | February 18, 2010
On The Primate Diaries, Eric Michael Johnson writes "not acting our age may be the very reason why we're so successful as a species." Like the bonobo which can be seen unlocking the cage of an unrelated individual just to share food, humans may retain juvenile characteristics that help us to "cooperate and share with others." But while sharing food is laudable, telling the world how drunk you got last night can be a bit less noble. Jonah Lehrer on The Frontal Cortex calls Facebook "a perfect example of too much information" and says that despite technological platforms, "our social lives…