Explore the The History of Our Tribe Hominini Textbook Part I An Introduction to Paleoanthropology Chapter 2 Primate Classification study material pdf and utilize it for learning all the covered concepts as it always helps in improving the conceptual knowledge.
. Primate Classification SYSTEMATICS THE SCIENCE OF CLASSIFICATION There are two means by which scientists classify organisms , classic taxonomy and . are trained in evolutionary theory , and both biologists and paleontologists rely principally upon . There is definite utility in using a combination of both systems , that is , the binomial ture ( genus and species ) of classic taxonomy combined with the arrangement of species in terms of shared characteristics . Classic taxonomy is based on the system begun by John Ray and elaborated by Carolus kingdom , phylum , class , order , family , genus , species , etc . It classifies organisms based on descent from a common ancestor , using similarities in physical characteristics . We are Homo sapiens , as distinct from other members of our genus , such as Homo ( Note that since the in is silent , it is sometimes omitted from the common name . refines classic taxonomy by linking organisms , based on the presence or absence of unique characteristics , into For example , if three species share a suite of characteristics but only two of them have a particular trait that is not present in more distantly related species , those two are more closely related and would be depicted as a separate grade . Figure depicts five primate grade . New world Old world Lemurs monkeys monkeys Apes Humans of Primates Figure of Primates Fetter , The following terms are used to delineate characteristics in primitive trait that is present in the ancestor as well as descendent species , for example , five digits ) in primates is an ancient trait seen in amphibians and reptiles . derived trait that is not found in the ancestor but is present in descendent species , for example , nails in primates . unique derived trait present in member species of a particular grade , for example , 12
the lack of a tail in apes . trait inherited by members of two or more grades from their common ancestor , wherein the trait was an , for example , in the various grades within our tribe , trait in more than one grade that evolved independently , for example , brachiation ( swinging by one arms ) in some New World monkeys and apes . PRIMATE CLASSIFICATION We are primates , that is , members of the order Primates ( The pie chart in Figure shows the various orders of animals within the class We are most closely related to tree shrews ( order ) and ( order , also known as flying lemurs ) Primates are distinguished by a suite of characteristics known as evolutionary trends ( see table below ) However , we do not exhibit all of them to the same degree , and some are absent in certain species or lineages . For example , retain a claw on the second digit of their feet , whereas do not ( more about the two primate groups later ) These trends were first proposed by and ( 1967 ) and Le Gros Clark ( 1959 ) and more recently have refined and added to the list . I 070 ! I mutton ( I Mann I I I I I noon ! I Sauna I I I Nan I I I Emu I I I I I Figure Orders within the class . Mammal species pie chart by is in the public domain . Primate Classification 13
PRIMA TE EVOLUTIONARY TRENDS Generalized , unspecialized skeleton No loss of limb bones from the ancestral condition . a Presence of a clavicle that allows greater mobility . Capable of varied movement and locomotion . Large , complex brain ( relative to body size ) especially cerebral cortex . Decreased reliance on olfaction Reduction of snout and olfactory bulb in frontal cortex . Increased reliance on vision a Enlarged visual cortex , greater visual acuity , and color vision . a , overlapping fields ( binocular ) of vision , and excellent depth tion . Prehensile ( grasping ) hands and feet and opposable thumb and big toe . Nails instead of claws . Long and life periods with greater reliance on learning . Tendency toward . Taxonomic charts of the living primates can be found below . The primates are divided into two major groups , which retain primitive characteristics , such as the lemurs of Madagascar and the of Africa , and the more derived , that is , the tarsier , monkeys , and apes . The older terms for the that are still in popular use are ( see figure 23 ) and . However , small , nocturnal prosimian from the islands of the Southeast Asian archipelago ) have characteristics of both groups . The primates have more typical mammalian noses or ( see Figure ) that are moist and more complex . They have a larger olfactory bulb in the frontal cortex of their brains and scent glands in various locations on their bodies . They use those glands to to other members of their species . We have simpler , dry noses and do not smell as good ! 14 The History of Our Tribe
Suborder Ta and of of SE Asian Africa and of Asia Archipelago Lemurs of Madagascar Figure Prosimian . Figure noses ( A through ) and the nose of a New World monkey ( noses by Reginald is in the public domain . As we learn more about biochemical and evolutionary relationships among the various groups of primates , primate taxonomy is changing . The New World monkeys ( see Figure ) have changed substantially in recent years , with the creation of multiple families that were formerly grouped into two or three . The Old World ( monkeys and apes ) and New World monkeys are also distinguished by our noses . Old World have more ovoid . nostrils , whereas New World monkeys nostrils are round and . Primate Classification 15
Suborder New World monkeys Family and marmosets Family Squirrel and capuchin monkeys Family Spider , howler , wooly monkeys , a Family , and titi monkeys Family Night monkeys Figure New World classification . The Old World monkeys ( see figure ) are divided into the , with their cheek pouches and more generalized diet , and the , with their complex guts . Think baboon ( Africa ) or snow monkey ( Japan ) for the former and colobus ( Africa ) or langur ( primarily Indian subcontinent ) for the latter . When asked , most people are more familiar with the , but if they see a picture of a colobus ( also known as a guereza ) leaping through the air with its white mantle of fur and tail flying ( or not see Figure ! I couldn find an action shot ! or a langur sitting on the steps of a temple ( OK , a fort . see Figure ! in India , they usually recognize them . The taxonomy of the apes ( see Figure ) has finally been updated . Until recently , humans were separated from the other great apes at the family level . All great apes are too closely related to be separated into families . The lesser apes , ie the gibbons and of Southeast Asia , are still separated into their own family , the . All of the great apes are now in the family , formerly our exclusive domain . The orangutans come out at the subfamily level , leaving the African great apes in the subfamily . The gorillas have their own tribe , using the genus Gorilla to form the name ) and if the chimps ( genus Pan ) are taken out of our tribe ( they are assigned the tribe Panini ! I did not make that up ! Some experts suggest that chimps and humans should be included in the same genus . 16 The History of Our Tribe
suborder Old World monkeys and apes Old World monkeys Family Subfamily Figure 26 Old World monkey . APE CHARACTERISTICS Why are sleeves always too me ?
We apes share a suite of characteristics ( in varying degrees ) and we humans have radically changed as we abandoned a more typical ape habitat and adapted to a more open terrestrial landscape . The table below lists great ape characteristics Great Ape Characteristics Relatively large brains . have a characteristic pattern of and fissures on one or more lar molars . Primate Classification 17
Suborder Old World monkeys and apes Superfamily Apes Family Great a es Lesser apes and ) Subfamily Gorillas , chimps , bonobos , and humans Tribe Gorillas Tribe Chimps and bonobos Tribe Humans Figure Ape classification . Honing complex consisting of large canines that are sharpened ( honed ) on the first lower premolar , termed a sectorial premolar . Upright trunk posture . Short , shallow , wide rib cage . High degree of mobility in joints of shoulders and wrists , termed the suspensory ing adaptation . Long arms and short legs . Long , curved hand and foot bones . Variable degree of sexual dimorphism ( differences between male and female ) in body size . 18 The History of Our Tribe
Figure colobus monkey . Colobus by Yak is licensed under . Figure . Fort by is licensed under BY 20 . Primate Classification 19 Low in humans , moderate in chimps , high in gorillas and orangutans . Pronounced male prognathism ( jutting jaws or muzzle ) and large canines , depending on species . Long life stages , especially the juvenile dependency period . Build nests . Capable of learning and using symbols . Tool use with some modification ( chimps and orangutans preparing a stick for probing ) The ancestor of the great apes was an arboreal climber . At some point , apes deviated from the more quadrupedal morphology , in favor of ( a more upright , shorter , broader , shallower trunk ( just think of our thorax versus a dogs ) elongated upper limbs and ( more mobile shoulder and wrist joints . While we can not swing by our arms as well as the lesser apes ( brachiation is the technical term ) we great apes retain the suspensory hanging adaptation and can swing to varying degrees , as long as the tree will support us . Adult male gorillas do not swing because they are too massive ! As , or bipedal apes , came to rely less on an arboreal environment , the bones of our ancestors hands and some foot bones became shorter and straighter and our legs became longer and more efficient for covering long distances on African landscapes . Beginning with the emergence of our own genus Homo ( we became increasingly ( ie . an increase in brain size relative to body size ) leaving our fellow great apes behind . While all great apes are sexually dimorphic in terms of body size ( males are larger than females ) humans are less so and the trend began even prior to our own genus . Depending on which fossil we include in our lineage , male canines were either monomorphic ( male and female canines were the same size ) or became less dimorphic over time . This is significant because male canine dimorphism is associated with competition for females , males bite one another ! If we accept , for example , that we are descended from the ( see Chapter ) that lived over , ancestral males did not have large canines . However , there is better evidence that we are descended from the and within that lineage , male canines were initially larger than females and became smaller over time . Apes live a relatively long time and consequently all of our life stages are prolonged as well , especially our juvenile dependency period . Of the nonhuman primates , orangutans win . Female orangutans have an birth interval ( ie . a period of time in between births ) of eight years and juveniles do not even start ing off until they are seven . That is not good news from a conservation perspective ! All great apes build nests and scientists speculate that our ancestors likely did as well , at least until they left the trees . We also use tools . Chimps are the champs when it comes to tool use , eg . nut cracking , ant fishing , etc . Orangutans are very adept at tool use as well , but their thumbs are short and more distant from their fingers , so that their opposability is poor . Consequently , they use their mouths to trim sticks and manipulate them for the desired task . In captivity , they also use their mouths to draw and paint . While gorilla tool use had been known from observations of gorillas in captivity , the use of a tool in the wild was finally recorded in 2005 when a female used a stick to test water depth . Of course , we humans are on a whole different level and we can trace the development of technology in the archaeological record to over . We have two language centers in our brain , and areas ( see Figure ) area is found in all Old World monkeys and apes it plays a role in the motor control involved with speech tion . As we well know from language studies , all nonhuman great apes are capable of learning and using symbols and have even made up a few . Washoe , the famous chimp that was taught American Sign Language , strung together the signs for water and bird , when she saw a duck for the first time . Where they fall short is in using syntax they are poor at correctly stringing symbols together into meaningful sentences . 20 The History of Our Tribe
However , the super bonobo at Sue Savage lab , does pretty well . Check him out in the video below . Figure and Novel Sentences by Iowa Primate Learning Sanctuary It is pretty convincing that he understands some syntax with following her commands , such as putting the pickles inside the vacuum cleaner versus the vacuum cleaner inside the pickles ! Okay , I made that one up but the things she has him do , in order to convince us that he understands , are amusing and amazing ! We and our ancestors , beginning with the genus Homo , also have area . While a homologous area is present in monkeys and apes , ours has much broader and is uniquely involved with speech comprehension . At what point our ancestors began to speak is a highly contested topic but the ical record provides some clues ( see Chapters 23 and 28 ) Figure and areas ( left side of brain ) by the National Institutes Health is in the public domain . Primate Classification 21
Great ape social organization varies by species . The chimps and bonobos ( genus Pan ) are most like the majority of human traditional societies in that they live in male , refers to the sex that remains in their natal group , ie . the group into which they were born . This type of social organization is seen in some ripe fruit specialists , such as the chimps and of Africa and the New World spider monkeys . Since fruit is an ephemeral resource , females can not defend it . Groups of related males defend a home range against outsider males . Females emigrate from their natal community and join a different community when they reach sexual . Group members come together intermittently into larger wherein they may interact . This grouping pattern is termed . Since males patrol and protect the area and females are large and powerful and can climb , the danger of predation is relatively low and they therefore have less of a need to congregate . The mating pattern is termed , meaning that males and females are promiscuous and may have multiple sexual partners . Males may attempt to monopolize and coerce females to mate but females are adept at getting around bullying males and may even mate with males side of their group . Orangutans are considered to be solitary and their prominent mating pattern is polygyny ( males have multiple mates ) wherein females in a given area usually mate with the resident , large , dominant male . Smaller males who are sexually mature but lacking the pronounced secondary sexual characteristics , such as facial pads ( termed flanges ) and an enlarged throat sac for loud calls , may try to forcibly copulate with females . Females are thought to monitor the dominant male location so that they can stay within calling distance if they are being harassed by subordinate males . Gorillas live in groups , except for the mountain gorillas , where two males may reside , an older dominant and younger subordinate . Both sexes tend to leave their natal group . Females join a male who may or may not already have other female mates . Thus the mating system is also polygynous . Males defend their females and offspring from outsider males who may be infanticidal . In mountain gorillas , females are thought to prefer groups with two males as they provide better protection for her offspring . It can thus be seen that there are characteristics of the human sexes in all three great ape genera ( plural of genus ) male defense and , female choice for dominant males and good genes , male try with females maximizing resources for themselves and offspring in chimps and bonobos , etc . 22 The History of Our Tribe