primates
emjohnson | July 23, 2009Primate sociality is linked to brain networks for pair bonds.
Social conservatives are fond of linking morality with monogamy and will be quick to condemn the moral crimes of adulterous felatio while ignoring the moral crimes of cutting social programs for poor mothers. However, in a bizarre twist, research suggests that morality and monogamy are closely intertwined, though it's doubtful many conservatives will champion the reasons why.
In the journal Science Robin Dunbar revisits the question with a unique perspective as to why some species (including humans) succeed so well as members of…
emjohnson | July 17, 2009How genes for altruism can benefit strangers as well as kin
The generosity of adoption has long been considered a unique human hallmark.
Image: Shadows of Forgotten Ancestors
For decades it was conventional dogma that humans were the only species that used tools. "Man the Toolmaker" was our celebrated designation. The hominin fossil Homo habilis (or "handy" man) was even defined within our genera primarily because the skeleton was associated with stone implements. However, when Jane Goodall discovered chimpanzees using modified sticks at Gombe to "fish" for termites, Louis Leakey famously…
gregladen | May 20, 2009You probably know that there is a new primate fossil, nicknamed "Ida," and that there is quite a buzz about it.
Darwinius masillae, aka Ida
Ida comes from fossil deposits in Germany, and was originally excavated in two different parts by private collectors, and only recently rejoined and recognized for the amazing fossil it is. This is considered to be a new genus, and is named Darwinius masillae
...holotype skeleton in right lateral view...
Ida is a 47 million year old adapid primate of outstanding, unprecedented state of preservation that seems to have some very interesting and…
edyong | April 20, 2009
Studying the way an animal moves by looking at its ears might seem like a poorly thought-out strategy. After all, short of watching it directly, most biologists would choose to look at more obvious traits like tracks, or limb bones.
But while an animal's limbs may drive it forward, its inner ear makes sure that it doesn't immediately fall over. By controlling balance, it plays a key role in movement, and its relative size can tell us about how agile an animal is.
When we walk, the image that forms on our retinas changes quite considerably. But no matter how fast or erratically we move,…
amillikan | March 10, 2009Among the non-coding DNA that composes a large percentage of the genomes of humans and other eukaryotic organisms, pseudogenes are genes that were once active but were rendered defunct by mutations at some point in evolutionary history. But some pseudogenes may regain their functionality. A study published in PLoS Genetics last week revealed that a gene that codes for a member of the immunity-related GTPase protein family, IRGM, was subject to a frameshift mutation in an ancestor of primates 40 million years ago, due to insertion of a small fragment of DNA. The non-functional pseudogene…
edyong | March 5, 2009The world of genetics is filled with stories that are as gripping as the plot of any thriller. Take the IRGM gene - its saga, played out over millions of years, has all the makings of a classic drama. Act One: setting the scene. By duplicating and diverging, this gene thrived in the cells of most mammals as a trinity of related versions that played vital roles in the immune system.
Act Two: tragedy strikes. About 50 million years ago, in the ancestors of today's apes and monkeys, the entire IRGM cluster was practically deleted, leaving behind a sole survivor. Things took a turn for the worse…
gregladen | February 16, 2009The incident just reported an hour or so ago is unusual, but not unexpected or unheard of.
A 200-pound chimpanzee kept as a pet and once used in commercials was shot and killed by police Monday after it mauled a woman visiting its owner and later cornered an officer in his cruiser, authorities said.
Stamford police Lt. Richard Conklin said the injured woman was hospitalized late Monday in "very serious" condition at Stamford Hospital; her identity was not immediately released. Conklin said she suffered "a tremendous loss of blood" from serious facial injuries.
source
gregladen | February 12, 2009Or not.
Much is made of the early use of stone tools by human ancestors. Darwin saw the freeing of the hands ad co-evolving with the use of the hands to make and use tools which co-evolved with the big brain. And that would make the initial appearance of stone tools in the archaeological record a great and momentous thing. However, things did not work out that way.
It turns out that up-rightedness (bipedalism), which would free the hands, evolved in our ancestors a very long time (millions of years) prior to our first record of stone tools. The earliest upright hominids that are…
gregladen | February 12, 2009And hominids.
We know the fossil record underestimates diversity at least a little, and we know that forested environments in Africa tend to be underrepresented. Given this, the diversity of Miocene apes may have been rather impressive, because there is a fairly high diversity in what we can assume is a biased record.
But I'd like to make the argument from another angle, that of modern ecological analogues. Let us assume that the greater apparent diversity of apes in the middle and late Miocene compared today can be accurately translated as a modern reduction in ape diversity. Not…
gregladen | January 11, 2009I have had a lot of students of whom I'm very proud because of their accomplishments both in research and generally. One of these students is Mark Foster, who is one of a very small number of undergraduates to engage in significant research at some of the key East African chimpanzee research sites. Unfortunately for me, I can't take a lot of credit for Mark's excellent research, because I played a much smaller role in working with him than did others, but I am still very happy with his successes.
I've got a peer reviewed paper by Mark that I'll be reviewing soon. In the mean time, have a…
gregladen | December 6, 2008Individual animals that live and and forage in groups may not always benefit from a particular move (to or from a foraging site) in the same way as other individuals in the group. Therefore, there must be some kind of negotiation among the critters. Theoretical work almost always seem to show that consensus based group decisions will prevail because this minimizes individual costs. The altnernative, despotic decision (where a dominant individual decides where the group goes) should rarely happen. But the theory is apparently weak because despotic decision making seems to occur in nature.…
gregladen | October 17, 2008
The Trivers Willard Hypothesis predicts that under certain conditions, individuals will bias their investment in offspring differently depending on the sex of the offspring. It is believed that this can be as extreme as infanticide or as subtle as providing different amounts of breast milk.
A new study by Katherine Hinde finds that macaques may do this. However, I think this may be counterintuitive.
Hinde uses data from 106 rhesus macaques (Macaca mulatta) to show that first time mothers produce richer milk when they have sons compared to when they have daughters. She suggests that "[t]…
gregladen | August 20, 2008A typical adult human recognizes that the image one sees in a mirror is oneself. We do not know how much training a mirror-naive adult requires to do this, but we think very little.
When a typical adult macaque (a species of monkey) looks in the mirror, it sees another monkey. Typical adult male macaques stuck in a cage with a mirror will treat the image as a fellow adult male macaque until you take the mirror out of the cage.
(Experiments that attempt to determine if an individual can recognize themselves in the mirror ultimately derive from what is known as the Gallup Test, after Gordon…
gregladen | August 18, 2008
The future for a large primate in a tiny patch of African forest looks bleak. Just three years after it was discovered, Tanzania's kipunji monkey is threatened with extinction ... researchers conducted more than 2,800 hours of fieldwork in the Southern Highlands and Udzungwa Mountains in Tanzania, where the kipunji was discovered. The team tallied just 1,117 individuals, and found that the monkey's range is restricted to 6.82 square miles of forest in two isolated regions.
The authors also discovered that illegal logging and land conversion has severely degraded much of the monkey's…
gregladen | July 30, 2008Austrian Franz Sikora was a fossil hunter and merchant of ancient bones working in the 19th centuyr. In 1899 he found the first known specimen, which was to become the type fossil, of Hadropithecus stenognathus in Madagascar. This is an extinct lemur. To be honest, I'm not sure when this lemur went extinct, but I think it was not long before Franz found the fossil.
The bones found in 1899 as well as other material have been sitting in an Austrian museum since.
Excavations at the same locality in 2003 recovered much more material from this species. Now, a team working mainly at a lab…
gregladen | June 27, 2008
Perhaps judging a man by his cologne isn't as superficial as it seems.
Duke University researchers, using sophisticated machinery to analyze hundreds of chemical components in a ringtailed lemur's distinctive scent, have found that individual males are not only advertising their fitness for fatherhood, but also a bit about their family tree as well.
"We now know that there's information about genetic quality and relatedness in scent," said Christine Drea, a Duke associate professor of biological anthropology and biology. The male's scent can reflect his mixture of genes, and to which…
gregladen | February 28, 2008This is a photograph of wild western lowland gorillas copulating in, sort of, the missionary position. This shot was taken in the Nouabale-Ndoki National Park in the Republic of Congo.
The female gorilla in the photograph, nicknamed "Leah" by researchers, has twice made history. In 2005 Breuer and others observed her using tools--another never-before-seen behavior for her kind in the wild. Leah tested the depth of a pool of water with a stick before wading into it in Mbeli Bai, where researchers have been monitoring the gorilla population since 1995.
"Understanding the behavior of our…
gregladen | February 28, 2008A DNA phylogeny based on over 200 species of lemurs and related species is now available.
Lemurs are part of the large group known as the strepsirrhine primates (yes, three r's...)From the abstract of this paper, coming out in March in Genome Research:
... strepsirrhine primates are of great interest ... due to their phylogenetic placement as the sister lineage to all other primates. Previous attempts to resolve the phylogeny of lemurs employed limited mitochondrial or small nuclear data sets, with many relationships poorly supported or entirely unresolved. We used genomic resources to…
gregladen | January 21, 2008Is 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 | January 18, 2008Two hundred pound robot lumbering along on tread mill, doing the bidding of a monkey several thousand miles away.An international and interdisciplinary team of scientists have developed a robot that will carry out physical activities in imitation of the activities of a monkey. The monkey and the robot are hooked together via the internet. The monkey has a brain-machine interface. When the monkey moves along on a treadmill, the robot mirrors those movements. The monkey and the robot need not be anywhere near each other, of course. In fact, it is probably a good idea to keep them in…