Or 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.
Continue reading Great Moments in Human Evolution: The Invention of Chipped Stone Tools
And 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 counting the relatively diverse lesser apes, there are five species (2 chimps, gorilla, human, orang) which can be further divided into 10 subspecies, across the entire old world.
Now look at the size range of all of the living apes. Gibbons are the smallest and gorillas the largest. When a family or subfamily of land mammal is diverse in a particular region (a biome or something larger than a biome) we tend to see that diversity played out along a spectrum of size, and against size we can find additional diversity derived from dietary or subhabitat differences and geography. It seems to me that there is room in the size spectrum between gibbons and chimps, and orangs and gorillas, and there is certainly room above the gorilla size as indicated by the existence in the fossil record of very large Asian forms.
We know that some of the later Miocene apes were bipedal, and it is starting to look like bipedalism or something like bipedalism is showing up among other apes in the Miocene as well. So perhaps there is a spectrum of locomotory pattern along which diversity may be spread.
This gives us a the following size classes: gibbon, siamang, [something in between], chimp, orang, [something in between], goriilla, [something bigger], or at total (a minimum?) of eight size classes across which apes might exist in a world in which apes are divers. Like the Miocene. If we add to this a more arboral form and a more bipedal form, perhaps we double the number, or perhaps we add about five new classes (I’m guessing that a Mighty Joe Young size ape would not have been bipedal!). This gives us about a dozen, conservatively estimated, niches when we divvy up size and so-called positional behavior.
To this we can add geography. It is probably reasonable to assume that a wetter, more forested middle and late Miocene Africa could be divided into at least four or regions, between the West/Central divide that modern biogeogrpahy tells us was effective at least in the Late Miocene, the Congo River divide, North/Central Africa, East Africa and Southern Africa. Let’s conservatively assume four, and let’s assume that only half (six) of the hypothesized ape species are divided among these areas. That means that 24 species are endemic to varoius regions, and six additional species are more widely spread for a conservative estimate of 30 species.
Among these species there may have been several bipedal forms, but only one of them (plus or minus a little hybridization hanky panky here and there) would have been the human ancestor. Of course, no one at the time suspected that …. (Or they probably would have done something about it.)
This is not an outrageous suggestion. The idea that if you went back in time to a more ape-rich time (and we know it was more ape-rich) and got a current copy of the Guide to the Mammals of Africa, the ape section would have a few dozen species, just like the monkey section or the antelope section today has a few dozen species.
Go apes!
I 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 look at this piece from Nature News
Researchers at the University of Minnesota’s Jane Goodall Institute Center for Primate Studies have now collated ten years of behavioural data on three male chimpanzee in Gombe National Park, Tanzania. Chimpanzees within the park have been routinely weighed by park staff, allowing Mark Foster and his team from the institute to work out which tactics chimpanzees of dramatically different sizes used both before and after they became alpha males….
The findings … are the first to suggest that physically smaller males make up for their reduced physical characteristics by using grooming to make allies who will aid them when their time comes to try and achieve alpha-male status, says Foster….
“It’s kind of like when I was a teenager and the football team’s quarterback lost the school’s popularity poll to a wimpy, unassuming fellow who was also quick-witted. The latter fellow was able to make friends through his sense of humour and charisma, and in turn achieved a kind of alpha status over the brutish quarterback,” he says.
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 animals he’s most closely related. “It’s an honest indicator of individual quality that both sexes can recognize,” she said.Lemurs, distant primate cousins of ours who split from the family tree before the monkeys and apes parted ways, have a complex and elaborate scent language that until recently was completely undiscovered by humans. Drea said it’s language that is undoubtedly richer than we can imagine.”All lemurs make use of scent,” she said. “The diversity of glands is just amazing.”Ringtailed males have scent glands on their genitals, shoulders and wrists, each of which makes different scents. Other lemur species also have glands on their heads, chests and hands. Add to these scents the signals that can be conveyed in feces and urine, and there’s a lot of silent, cryptic communication going on in lemur society.Wearing a scent-based nametag declaring one’s genetics is probably useful in avoiding aggression with closely related males, Drea said. It’s also quite likely to help prevent inbreeding by signaling family relationships to females, but the research to prove that is still ongoing.For this study, Drea and postdoctoral fellows Marie Charpentier and Marylène Boulet focused solely on male ringtailed lemurs living at the Duke Lemur Center.The males have a gland and spike on each wrist that is used to scratch and mark saplings with highly aromatic scents. A pair of glands on the shoulders “like misplaced nipples” manufacture squalene, a scent molecule that works like glue to keep the more aromatic compounds in place longer. Males can be seen dabbing the wrist gland on the chest gland and then scratch-marking. The wrist glands are also central to the “stink fighting” of ringtails, in which they rub the glands along the length of their bushy tails, and then foist them into each others’ face to express dominance.Most importantly, the male also has a scent gland on his scrotum that becomes critical to marking territory and advertising fitness during mating season. He does a handstand and rubs this gland directly onto a tree trunk to let any interested lemurs know who he is and what he’s made of.Scent not only speaks volumes, it’s physiologically expensive to make, Drea said. When a lemur is ill or socially stressed, its scent changes dramatically. “If he loses his signals, it’s quite likely its because he’s less genetically fit,” Drea said. “And his sexual or social partners can know that.”Female ringtailed lemurs have just one scent gland in the genital area, but their scent is more complex than the males’. Via scent, females may advertise not only their fertility, but the presence of a pregnancy and how far along it is, Drea said….source and more
This 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. Continue reading Wild Gorillas Gone Wild
A DNA phylogeny based on over 200 species of lemurs and related species is now available.
Continue reading Lemur Family Tree Mapped
Is 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 has shown that it is in fact rare … the vast majority of calories consumed by human foragers in certain societies and at certain times of the year comes from a sharing system, while the fast majority of calories consumed by chimpanzees is hand to mouth without sharing.
Two 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 separate places. If the robot knew that its entire existence was really just to be an automaton doing the bidding of a monkey, if it realized that it was a mere simian-driven Golem, it may become depressed or go berserk. Continue reading Robot Does Monkey’s Bidding
Traveling from Ecuador to Africa, Jane Goodall takes the audience on an ecological journey, discussing highlights and low points of her experiences in the jungle. She shows how progress is helping research (DNA analysis) and hurting the environment (clear-cutting). And she draws a dozen parallels between primate and human behavior, making the point that we really aren’t all that different. Our big advantage, she says, is the ability to communicate with sophisticated spoken language — yet, sadly, we are abusing this power and destroying the planet. She urges the TED audience to behave differently, and use their higher powers to correct the planet’s course.
Continue reading Jane Goodall: What separates us from the apes?
There is a new baby orangutan born at the Como Zoo in Saint Paul, Minnesota. I mention this for the edification of my local readers (who probably already know about it) and not as a statement of support or opposition to zoos, orangutans, or babies.Details, including photographs, here on Science Buzz.
Gorilla gorilla
Rwanda introduces ‘gorilla tax’ from PhysOrg.com
Rwandan companies using the country’s famous mountain gorillas’ image for marketing purposes will have to pay a tax aimed at financing the endangered species protection, officials announced Monday.[…]
It may be nothing more than slinging shit, but when you run out of shit:
Wild gorillas have been seen using “weapons” for the first time, giving a new insight into how early man learned to use sticks and stones for fighting and hunting millions of years ago.Researchers observed gorillas in the Cross River area of Cameroon throwing sticks, clumps of earth and stones at human “invaders”.It is the first time that the largest of the great apes has been seen to use tools in an aggressive way.