Anthropology help wanted
THE LIVING PRIMATES
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Primatology: Why Study the Living Primates?
1950s = rise of field of primatology
Primatologist: A scientist working directly or indirectly with nonhuman primates in a variety of settings
Goals of primatology:
Reconstruct early hominin & human adaptations, behaviors by providing models & analogues
Comparison to understand ourselves
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-so, who studies primate behavior and how do they do it?
-primatologists are scientists who study the evolution, anatomy, and behavior of non-human primates
-primatologists can be trained as zoologists or biological anthropologists
-the earliest studies of nonhuman primates was in the 1920s and 1930s but in the 1950s is when we really see primatology as a discipline take off
-Robert Yerkes, an American psychologist, sent his students into the field to study gorillas, chimps, and howler monkeys
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Are we looking through a window or in a mirror?
http://domain.me/emoticons/
One of the issues we face in primatology is that it is hard to be an objective observer. One must recognize how our own culture affects interpretation of primate behaviour: How much do we see because we want to see it? How much are we missing because we aren’t looking for it?
So beware direct comparisons between primates (and between living primates and our fossil ancestors):
Modern primates provide clues:
Useful as models, not because they represent an earlier stage in our evolution as a species (THEY DO NOT), but because they are all we have for even remotely related mammals – there are no living populations of related hominins.
We must be critical of interpretation and validity of the models created (Anth209!).
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What we have been able to show?
Primates are intelligent
Impressive skills re: tool use
Ability to manipulate symbols
Ape-language experiments
Ability to reason analogically
Ability to learn and transmit knowledge across generations
Sense of self
ability to recognize oneself (the “mirror test”)
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What we have been able to show?
Primates are social
Behave differently to differently dominant individuals
Recognize & respond to individual personalities
Recognize kin from non-kin
Ally with close kin first in conflicts
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What we also know . . .
No significant relationship between environment & primate social organization
Primates are all about dietary & behavioral plasticity
Monogamous pairs
Rare in non-human primates
Those monogamous non-human primates typically lack sexual dimorphism & have social organization where sex roles are undifferentiated
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Note violence (including sexual violence) and homosexuality has been documented but not in all groups. This demonstrates that these are a) not exclusive to humans and b) have a biological component.
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Primate Characteristics & Taxonomy
This is a HUGE field of study so our goals at the 101 level are to understand
What is a primate
What characteristics do all primates share
How primates vary
What we can learn from non-human primates to better understand ourselves and our evolution (think forces or “fingers” of evolution…)
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PRIMATE CHARACTERISTICS: LeGros Clark (1963)
So what is a primate
-identifying single traits that define the primate order isn’t easy because compared to most mammals, primates have remained quite generalized (this is likely an advantage for us...)
-that is, primates have retained many ancestral or primitive mammalian traits that many other mammals have lost over time
-because primates are remarkably generalized, they can’t be defined by one or even a few traits they share in common
-therefore, anthropologists have drawn attention to a group of characteristics that, when taken together, more or less characterize the entire primate order
-still, these are a set of general tendencies that aren’t all equally expressed in all primates
-in addition, while some of these traits are unique to primates, many others are retained primitive mammalian traits
-so, to get an overall picture of what makes a primate, people usually focus on their anatomical, life history, and behavioural traits
-their limbs and locomotion, teeth and diet, senses, brain, and behaviour is reflective of a common evolutionary history with adaptations to similar environmental challenges
Increase in brain size relative to body size and increase in the complexity of the neocortex.
Reduction in both the projection of the face and the reliance on the sense of smell
Increasing dependence on the sense of sight resulting in the relocation of the eyes onto the same plane on the front of the face so the visual field of each eye overlaps, producing depth perception (stereoscopic vision)
Reduction in the number of teeth
Grasping (prehensile) hands and feet: includes opposable thumbs and great toes, nails rather than claws, sensitive pads on tips of fingers and toes, and dermal ridges/friction skin on the digits, soles, palms, and underside of prehensile tails
Important is distinction between homology (similarities because of shared ancestry) versus analogy (similar adaptation to similar selective pressures, not shared ancestry)
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Primate Characteristics
This table considers these characteristics of primates using principles from evolutionary theory
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Lemurs and Lorises
Tarsiers, Monkeys, Apes, Humans
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See Figures 4.3 (p.73) and 4.12 (p.83)
Cladistic taxonomy of the primates.
-instead of simply moving tarsiers into the suborder Anthropoidea, one scheme places lemurs and lorises in a different suborder, Strepsirhini instead of Prosimii
-in this classification, tarsiers are included with monkeys, apes, and humans in another suborder, Haplorhini
-in this classification, the conventionally name suborders Prosimii and Anthropoidea are replaced by Strepsirhini and Haplorhini
-this designation has not been universally accepted
so, if you see the term strepshirhini, you know we are referring to lemurs and lorises
-this classification system makes the biological and evolutionary statement that all the strepsirhine species are more closely related to one another than they are to any of the haplorhines
-likewise, all haplorhine species are more closely related to one another than they are to any of the strepsirhines
What is represented here as the “alternative” classification has been increasingly accepted as the correct one thanks to insights from genetics but also following core principles of cladistics
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Suborder: Strepsirhines
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Lemurs, Lorises, and Galagos
Old World tropics and subtropics
Retain some primitive traits not seen in other primates
Best living analogy to earliest fossil primates
-the first group we are going to talk about is the suborder of Strepsirhines
-the strepsirhine suborder is made up of the lemurs and lorises
-Strepsirhines are found in throughout the Old World Tropics and subtropics, in places such as Madagascar, India, and Africa
-Lemurs, Lorises, and galagos, the strepsirhines, are the most primitive of all primates
-remember that by primitive I mean that strepsihrines, taken as a group, are more similar anatomically to their earlier mammalian ancestors than are the other primates (tarsiers, monkeys, apes, and humans)
-in evolutionary terms, the strepsirhines are among the oldest living primates, making them a good group to study in order to understand fossil primates
-so, they tend to retain certain ancestral characteristics, such as more pronounced reliance on olfaction
-they are also the most varied category of primates
-many characteristics distinguish lemurs and lorises from the haplorines, including eyes place more to the side of the face, differences in reproductive physiology, and shorter gestation periods
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Suborder: Strepsirhines
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Characteristic traits:
Good sense of smell (olfaction)
Rhinarium – moist nose
Prehensile hands and feet with nails on most digits
Tooth comb
Stereoscopic vision with orbits enclosed by a postorbital bar
Dental formula: 2133/2133
-many of strepsirhines are nocturnal (active in the night), hence:
They have a more developed sense of smell than other primates (wet, "naked" doglike nose) – referred to as the rhinarium
large eyes
- all have a "grooming claw" on the second toe only; nails on other digits
- all have a "dental comb" comprised of the four lower incisor teeth and the lower canines, which are long, narrow, and close together, for use in grooming fur and gathering food
-the mandible is also unfused, there is a plate of cartilage in between, this gives the mandible a v-shaped appearance
-all have the post-orbital bar but lack the post-orbital plate, like haplorhines do
-most have all three premolars so their dental formula is 2133
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Suborder: Strepsirhines - LEMURS
Lemurs
Madagascar
60 species exist
5 inches to 2 to 3 feet tall
Varied locomotory patterns
Grooming claw, postorbital bar, tooth comb, unfused mandible, and 2133/2133
Lemurs (only in Malagasy Republic – ex-Madagascar)
Only diurnal prosimian (competition).
-found only on the island of Madagascar, off the coast of Africa
-60 surviving species of lemurs exist today
-they range in size from the small mouse lemur at 5 inches tall to the Indri at 2 to 3 feet tall
-the larger lemurs are diurnal while the smaller, ones are nocturnal
-many are primarily arboreal, others such as the ring-tailed lemur are more terrestrial
-have all the classic strepsirhine traits, grooming claw, postorbital bar, tooth comb, 2133/2133
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LORISES & GALAGOS
Lorises (Africa, Asia). Nocturnal.
Galago = Bush Baby
Lorises
Resembles the lemur
8 species of lorises
India, Sri Lanka, Southeast Asia, and Africa
Also includes Galagos
Arboreal quadrupedalism
Infant parking
Grooming claw, postorbital bar, tooth comb, unfused mandible, and 2133/2133
-Lorises, which resemble lemurs, are nocturnal, meaning they are active during the night
-there are at least eight loris species, all of them found in tropical forest and woodland habitats of India, Sri Lanka, Southeast Asia, and Africa
-also included in the same category are 6 to 9 galago species, which are widely distributed throughout most of the forested woodland savannah areas of sub Saharan Africa
- locomotion in lorises is a slow, cautious, climbing form of quadrupedalism
-the flexible hip joints permit suspension by hind limbs while using the hands in feeding
-all galagos, however, are highly agile vertical clingers and leapers
-both loris and galago females practice infant parking
-this sounds dangerous, but lorises first bathe their young with saliva that can cause an allergic reaction sufficient to discourage most predators
-lorises exhibit good grasping and climbing abilities and well-developed visual apparatus
-finally, all lorises and galagos exhibit the classic strepsirhine traits, grooming claw, postorbital bar, tooth comb, 2133/2133
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Suborder: Haplorhines
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‘Higher primates’
Tarsiers and Anthropoids (Monkeys, Apes, and Humans)
Share many traits not seen in Strepsirhines
The tarsier is a problem here since it shares many traits with both Strepsirhines and Haplorhines
-Haplorhines, also considered as the “higher primates”, include the tarsiers, new and old world monkeys, apes, and humans
-obviously since they are in their own suborder, they share many traits not seen in the strepsirhine order
-however, the tarsier, posses a problem to taxonomists since it exhibits traits that are typified in both Strepsirhines and haplorhines
-so, as we go through these next couple of slides, you will notice that there will be some comments with regards to the tarsier, who might not show the complete set of traits that characterize the haplorhines
but, we have to include it somewhere
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Suborder: Haplorhines
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Differences from Strepsirhines include:
Increase in body size
Larger brain in relation to body size
Reduced reliance on olfaction
Absence of the rhinarium
Greater degree of colour vision
More generalized dentition
-Haplorhines differ from Strepsirhines in a number of ways
-now we’re going to go over some general traits, don’t forget that the tarsiers will pose a problem for these generalizations
1. in general, haplorhines such as monkeys, apes, and humans have a larger average body size
2. they have a larger brain, and of course this is in absolute terms and relative to body weight
3. they have a reduced reliance on olfaction, so this would reduce the size of the snout
4. they do not have a rhinarium like the strepsirhines did
-this means that the skin found covering the face is also in the nose area
-the nose is not moist
-5. they also have a greater degree of colour vision
6. they also have a fully enclosed eye orbit in comparison to the postorbital bar in strepsirhines
7. the mandible is fused giving it a more U-shape (not in Tarsiers)
8. they definitely have a more generalized dentition, and have lost the dental comb
-teeth wise, the more advanced haplorhines such as the old world monkeys, apes, and humans have one less premolar in each quadrant
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Suborder: Haplorhines - TARSIERS
Tarsiers
5 recognized species
Restricted to Southeast Asia
Nocturnal
Vertical clinging and leaping
Problem species: blend of characteristics
Rotate head 180 degrees
Grooming claw, postorbital plate, unfused mandible, and 2133/2133
-alright, now for the trouble species, the reason for trouble in classifying primates
-there are five recognized tarsier species, all of which are restricted to southeast asia
-their name refers to the presence of two highly elongated tarsal bones in their feet
-these long bones give extra leverage for leaping and searching for prey
-they inhabit a wide range of forest types, from tropical forest to backyard garden
-tarsiers are nocturnal and used vertical clinging and leaping to surprise prey (a lot of insects)
-as already mentioned, tarsiers present a complex blend of characteristics not seen in other primates
-they’re unique in that their enormous eyes, which dominate much of the face, are immobile within their sockets
-to compensate for this inability to move their eyes, tarsiers, like owls, can rotate their heads 180 degrees
-each of their eyes is about the size of their brain!
-similar to the Strepsirhines, tarsiers have a 2133 dental formula and a grooming claw
-unlike the Strepsirhines, the Tarsier has a postorbital plate, meaning that its orbits are completely enclosed by bone
-also, unlike the Strepsirhines, the tarsier does not have a tooth comb
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SUBORDER HAPLORHINES InFraorders: Platyrrhines and Catarrhines
Platyrrhines:New World
Monkeys
Catarrhines:Old World
Monkeys, Apes, Humans
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Platyrrhines – New World Primates
Marmosets, tamarins
Claws, not nails
Commonly birth twins
Considered to be monogamous
Squirrel monkeys (Saimiri)
Spider monkeys (Ateles)
Capuchins (Cebus)
Howler monkey (Alouatta)
Owl monkey (Aotus)
Titi (Callicebus)
Callitrichidae (callitrichids)
Cebidae (cebids)
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Found in forested areas in southern Mexico and Central and South America
Common traits:
Diurnal
Flat nosed/faced
Small bodied, some have prehensile tails
-the new world monkeys can be found in a wide range of arboreal environments throughout most forested areas in southern Mexico and Central and Southern America
-they exhibit a wide range of size, diet, and ecological adaptations
-they range in size from the tiny marmosets and tamarins ~12 ounces to the 20 pound howler monkeys
-New world monkeys are almost exclusively arboreal and some never come to the ground
-like old world monkeys, all except one species are diurnal
-one characteristic that distinguishes New and Old world monkeys is the shape of the nose
-NWM have broad noses with outward-facing nostrils, whereas old world monkeys have narrower and more downward facing nostrils
-because of their outward-facing nostrils, NWM have been placed into the platyrrhini infraorder and old world monkeys in the catarhini infraorder
-nwm are called platyrrhini, in French, plat, means flat.. so they have flat noses
-the new world monkeys have been subdivided into other groups such as families
-new world monkeys are characteristically small bodied, have 3 premolars like all the other nonhuman primates we have discussed so far, and are arboreal
-some new world monkeys posses a prehensile tail
-this prehensile tail acts like a 3rd appendage
-the tail can also be used to suspend the body from a branch so the hands and feet can be used to feed
-anatomically, like I said their dental formula is 2133/2133, they have a postorbital septum, and have no tooth comb or grooming claw
-you can see how they are similar to tarsiers…
Two families
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CALLITRICHIDS
Callitrichids
Left = Marmosets
Right = Tamarins
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CEBIDS
Cebids cont.
Squirrel Monkey: Left
Howler Monkey: Right Upper
Titi Monkey: Right Lower
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Catarrhines – Old World Primates
cata = downward, rhini = nose
5 Families:
Cercopithecidae (e.g. baboons, mandrills)
Colobidae (colobus, langurs, proboscis)
Hylobatidae (gibbons)
Pongidae (orangutan, chimpanzee, gorilla)
Hominidae (Homo sapiens sapiens)
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-except for humans, old world monkeys are the most widely distributed of all living primates - they’re found throughout sub-saharan Africa and southern asia and their habitat ranges from tropical jungles to semiarid desert and even to seasonally snow-covered areas in northern japan
-most old world monkeys are quadrupedal and primarily arboreal, but some such as baboons are also adapted to life on the ground
-because old world monkeys have downward facing nostrils, they are placed in the catarrhini infraorder
-locomotion in old world monkeys includes arboreal quadrupedalism, terrestrial quadrupedalism, and semi-brachiation and arobatic leaping
-old world monkeys have areas of hardened skin on their buttocks called ischial colosities that serve as sitting pads
-anatomically, old world monkeys have a postorbital plate
-they also lack a tooth comb and grooming claws
-however, unlike all the other non-human primates that we’ve discussed so far, old world monkeys have 2 premolars, so their dental formula is 2123/2123, the same as apes and humans, the next group that we will be discussing
-examples of old world monkeys include langurs, leaf monkeys, macaques, baboons etc.
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Family: Cercopithecidae
Cheek pouches (store extra food)
Ischial callosities (sitting pads)
Wide distribution in Africa & Asia
Broad adaptations to arboreal, forest floor, terrestrial, open-country environments
Most extensive adaptation (excepting Homo) to terrestrial environment
Some cercopithecids extreme sexual dimorphism
Many in multi-female, multi-male societies
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CERCOPITHECIDS
8 Genera
Genus:
Cercopithecus (guenons): Upper Right
Erythrocebus (patas monkeys): Bottom
Papio (baboons): Upper Left
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CERCOPITHECIDS
8 Genera
Genus:
Mandrillus (mandrills): Upper Left & lower right = example of sexual dimorphism
Macaca (macaques): Upper Right
Also not pictured:
Theropithecus (geladas)
Cercocebus (mangabeys)
Miopithecus (talapoins)
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Family: Colobidae
Often referred to as “leaf-eating monkeys”
Bulk of food = leaves
Sacculated (chambered) stomachs (digest cellulose)
Africa & Asia
Arboreal & leapers
Often polygynous (single male, multi-female)
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3 genera:
Colobus: left
Presbytis (langur): middle
Nasalis (proboscis): right
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Family: Hylobatidae
Often referred to as “lesser apes” because of smaller relative size
Occur in SE Asia
Extremely territorial
Excellent brachiators
Small, monogamous groups
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-gibbons and siamangs
-found in the southeastern tropical areas of Asia
-smallest of the apes, with a long slender body
-the most distinctive anatomical features of gibbons and siamangs are adaptations that facilitate brachiation
-these include extremely long arms, long permanently curved fingers, short thumbs, and powerful shoulder muscles
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Superfamily: Hominoidea
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Apes and Humans
Apes and humans differ from the previously mentioned species by the following characteristics:
Larger body size
Two (2) premolars (2123/2123)
No tail
Short trunk
Arms that are longer than legs (not humans)
Shoulder modifications
More complex behaviour
More complex brain
> infant care
-the other large grouping includes apes and humans
-this group includes gibbons, the great apes the orang-utan, gorilla, chimps, bonobo, and the hominids, us.
-apes and humans differ from monkeys in the following ways:
1. generally larger body size (except for gibbons and a few other species)
2. 2 premolars, not 3
3. absence of a tail
-both humans and apes don’t have tails
4. shortened trunk (lumbar verts shorter and more stable)
5. arms that are longer than legs (only in apes)
6. differences in position and musculature of the shoulder joint as related to an adaptation for suspensory feeding and locomotion
-this allows for brachiation, or swinging from the trees as seen in gibbons
7. more complex behaviour
8. more complex brain and enhance cognitive abilities
9. increased period of infant development and dependency
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The “Trimates” or “Leakey’s Angels”
Dr. Jane Goodall
Dr. Dian Fossey
Dr. Birute Galdikas
These three women were groundbreaking pioneers in primatology and have contributed much to our understanding of the great apes. While the work of Dr. Goodall is very well known, I also wanted to include Drs. Fossey and Galdikas to acknowledge the roles they played in transforming this subdiscipline within biological anthropology. Importantly all three fought (and sadly Dr. Fossey lost her life in her battles to protect mountain gorillas) for the rights of our closest living relatives and advocated for their ongoing conservation and protection. We have much to learn from the great apes but we also have to be cognizant of the threats to them from us and the loss of their habitats from human development and resource extraction.
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Family: Pongidae (“Great Apes”)
4 genera:
Orangutan
(Pongo pygmaeus)
Borneo & Sumatra (fossils widely distributed throughout Asia)
Gorilla (Gorilla gorilla)
Common chimpanzee
(Pan troglodytes)
Pygmy chimpanzee (bonobo) (Pan paniscus)
African
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Pongids’ General Characteristics
Have anatomy suited for brachiating, but all use variety of locomotion
All pongids spend time traveling, feeding on the ground
Orangutans tend to be solitary with overlapping male-female ranges
Gorillas live in societies comprising one fully adult male & multi-females
Chimps live in large, fluid social groups
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PONGIDS
-orangs are found on the Indonesian islands of borneo and Sumatra.
they are found in heavily forested areas. the name orang-utan means wise man of the forest
-they are slow, cautious climbers whose locomotor behaviour can be best described as four hands
-organgs exhibit crazy sexual dimorphism, males are quite large and may weight more than 200 pounds and females are usually around 100 pounds
-this species has been extensively studied by birute galdikas, a famous primatologist
-gorillas are the largest of all living primates
-they are found in western and eastern equatorial Africa, and are of course endangered
-locomotion wise, they get around by a subcategory of quadrupedalism called knucklewalking
-like oranges, gorillas exhibit pronounced sexual dimorphism, and we’ll be seeing this in the lab
-this species has been extensively studied by the late primatologist, Diane Fossey, some of you may have seen gorillas in the mist
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Pongids – Pygmy Chimpanzees (bonobos)
-chimps are probably the best known of all nonhuman primates
-today, when not found in zoos or circuses, the natural range of the chimp is in equatorial Africa, in a broad belt from the atlantic ocean in the west to Lake Tanganyka in the east
-they are not as sexually dimorphic as oranges and gorillas
-in addition to quadrupedal knuckle walking, chimps may brachiate while in the trees
-while on the ground they do frequently walk bipedally for short distances
-it was the famous primatologist, Jane Goodall that made these little guys so popular!
-bonobos, are found only in an area south of the Zaire river in the Democratic republic of congo
-bonobos are one of the least studied of the great apes
-they bear strong resemblance to chimps, and are just a little smaller
-because of this people have called them pygmy chimps
-they are more arboreal than chimps and are less excitable and aggressive
-people like to talk about bonobo sexuality
-it is definitely different than all other non human primates
-they copulate frequently and seem to use sex to defuse potentially tense situations
-sexual behaviour between members of the same sex is also common
-they’ve been called the make love not war primate society
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Family: Hominidae – Humans
Anatomically generalized
Habitual bipedal locomotion
Large brains, flat faces, small front (anterior) teeth
Sexual dimorphism not pronounced vs. pongids (male gorilla = 200 kg)
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Brief Highlights of Primate Evolution
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Figure 4.12 (p.83)
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The Emergence of Primates
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Eocene (55 - 34 mya)
First undisputed primates
Found everywhere except Australia, Antarctica, and South America
ADAPOIDS
OMOMYOIDS
-there is no dispute however about fossils dating from the early Eocene, about 55 mya.
-unlike the plesiadapiforms, the euprimates, meaning, true primates had clear primate characteristics
the euprimates consist of two closely related, highly successful groups, the adapoids and the omomyoids
Adapoids
Ancestral to lemurs, lorises, and galagos (strepsirhines)
Primitive generalized dentition
Relatively large in body size
Leapers and slow climbers
Fruit and leaf diet
Diurnial adaptation
Omomyoids
Ancestral to tarsiers, monkeys, apes, and humans (haplorhines)
Variable dentition
Relatively small bodied
For most forms:
Arboreal leaping
Diet of insects and fruit
Nocturnal
-the adapoids led to modern lemurs and lorises (strepsirhines) and the omomyoids led to tarsiers and anthropoids (haplorhines)
-however other textbooks don’t agree with this, and say one group led to another
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Early Higher Primates
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By late Eocene to Oligocene (34–23 mya)
Many higher primate species
Fayum Depression in Egypt
Change in world climate (cooler and dryer) saw many pecies go extinct
Parapithecidae
e.g., Apidium
Propliopithecidae
e.g., Aegyptopithecus
-so, up until now we have been talking about the lower primates, and their relatives
-so, lower primates like lemurs, lorises, galagoes, and tarsiers
-but, what brought on the evolution of higher primates or monkeys, apes, and humans?
-these primates first appeared in the late Eocene and early Oligocene epochs
-the earliest higher primates are simple monkeys
-later, apes appeared and they were more generalized than the ones we know today
-all of this occurred in a period of climatic fluctuation where temperatures were higher than usual but, at one point, sometime during the Miocene, temperatures started to cool. So was it the environment that allowed for more complex apes?
-ok, let’s go over both Apidium and Aegyptopithecus quickly
-Apidium is a small monkey-like arboreal quadruped; it has three premolars, as do most Prosimians and New World Monkeys; it is thought to have done a lot of leaping and was diurnal and ate mostly fruits and seeds . It is definitely the most primitive of the anthropoids. Some researchers think that a member of Apidium’s family could be ancestral to New World Monkeys
-Aegyptopithecus, also an arboreal quadruped, was larger than Apidium. They are thought to look like howler monkeys. it is thought to have ate mostly fruit and leaves and to have lived during the day. its dental formula, like apes and humans is 2123/2123
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Miocene Anthropoids
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Miocene (23–5 mya)
Early Miocene “Proto-Apes”
Mostly in Africa
Best known genus is Proconsul (20–18 mya)
-the Miocene is the geological epoch that began around 23 mya and lasting until 5 mya; -we will discuss the Miocene in three periods, the early, middle, and late
-during this time, monkeys and apes clearly diverged in appearance, and numerous kinds of apes appeared; we won’t be talking about monkeys since their fossils dating to the Miocene are sparse instead we will be focussing on the apes
-it was during the Late Miocene, somewhere between 8 and 5 mya that the direct ancestor of humans may have emerged in Africa; this is pretty exciting!
- But first for the early Miocene: most of the fossils from the early Miocene are described as proto apes, they have been found mostly in Africa
- the best-known genus is Proconsul: dated to about 20-18 mya; it was much bigger than any anthropoids of the Oligocene; it lacked a tail, which is definitely a characteristic of the hominoids; like the previous Oligocene anthropoids, Proconsul was primarily an arboreal quadruped; based on dental morphology, they appear to have been fruit-eaters and some leaves
-until recently, Proconsul was thought to be the last common ancestor of the great apes and hominids but a new species of Miocene ape, called Morotopithecus bishopi has since been found which is a possible contender
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Miocene Anthropoids
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Miocene (23–5 mya)
Middle Miocene Hominoids include:
Kenyapithecus
Gigantopithecus
Largest primate to have ever lived
Thick tooth enamel
Robust jaws, ate nuts and seeds
-sometime around 17 mya a large number of distinct anthropoid species emerged during the warmer Miocene epoch
-these forms were distributed throughout Africa, Europe, and Asia and included Kenyapithecus and Gigantopithecus
-Kenyapithecus had many of proconsul’s features, but their teeth and faces resemble those of more modern hominids
-Kenyapithecus had very thick enamelled teeth and robust jaws suggesting a diet of hard tough foods
-it is thought to have lived mostly on the ground, using some primitive form of knuckle-walking
-Gigantopithecus, an asian form, weigh up to 660 lbs!
-it is definitely the largest primate to have ever lived!
-when you hear of sasqwatch, these are the guys u are hearing about
-not only are they the largest of all primates, but they lived a pretty long time, they are thought to have lived with homo erectus!
-like Kenyapithecus, giganto had thick-enamelled teeth and large, think-boned jaws adapted for eating very hard foods like nuts and seeds
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Miocene Anthropoids
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Late Miocene Hominoids include:
Sivapithecus (12–8 mya)
Primarily in Western and Southern Asia
Thick enamel, ate seeds and nuts
Once thought to be ancestral to orangutans
Dryopithecus (12–8 mya)
Primarily in Europe
Thick tooth enamel and lighter jaws
Ancestor to apes and humans?
-from the end of the middle Miocene into the late Miocene, the apes diversified and moved into many areas; fossils are abundant in Europe and asia, less so in Africa
- late Miocene hominids include sivapithecus and dryopithecus
-sivapithecus, known for it’s thickly enamelled teeth, was remarkable similar in facial features to modern orangutans; it was once thought to be their ancestors
-Dryopithecus has thinner tooth enamel, lighter jaws, all traits that make it look like modern African apes because of this, it is thought to a modern ape ancestor, either asian or African so as you can see, things can get a little complicated!
-Miocene apes mostly vanish from the fossil record before the end of the Miocene, except for Gigantopithecus
-this may have resulted from a change to cooler drier climate which would have reduced the extent of forests
-so, the late Miocene fossil record for anthropoids is poor
-modern apes and early hominids must be descended from Miocene apes but it’s not clear which one!
-in the next lecture we will look at the divergence of hominids during the late Miocene
-so we will be looking at the first potential hominids
-but first we will look at one of the major trends in hominid evolution – the development of bipedal locomotion
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Next Topic
Questions ?
Concerns ?
Problems ?
Human Evolution
Dating Techniques
Readings:
Chapter 5
Hominin Evolution Study Guide
Dating Techniques Study Guide
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