Download Introduction to Primates: Studying Primates and Their Evolution and more Study notes Physical anthropology in PDF only on Docsity!
1 Introduction to PrimatesIntroduction to Primates
Anth 1013 Lecture Anth 1013 Lecture
27 September 200427 September 2004
2 How We Study PrimatesHow We Study Primates
§ § Comparative methodComparative method
§§ Looks at similarities/differences between closelyLooks at similarities/differences between closely--related formsrelated forms
§ § Anatomy, genetically, behaviorally, etc.Anatomy, genetically, behaviorally, etc.
§§ Adaptive significance of certain physical and behavioral systemsAdaptive significance of certain physical and behavioral systems
§ § Overview of humans (Overview of humans ( Homo sapiensHomo sapiens ) and over 200 species of non-) and over 200 species of non-humanhuman
primates (prosimians, monkeys, and apes)primates (prosimians, monkeys, and apes)
3 Remember…Remember…
§ § Evolution isEvolution is notnot “goal“goal--directed”directed”
§§ Living species not superior to evolutionary ancestorsLiving species not superior to evolutionary ancestors
§ § Living species (including humans) are not the “end all, be all”Living species (including humans) are not the “end all, be all”
§§ We are not seeing an apex or final stage of primate lineagesWe are not seeing an apex or final stage of primate lineages——those becamethose became
extinct!extinct!
4 Where are We?Where are We?
§ § Mammals (the classMammals (the class MammaliaMammalia ))
§§^ Over 4000 extant speciesOver 4000 extant species
§§ 3 major subgroups3 major subgroups
§ § EggEgg--laying (ducklaying (duck--billed platypus and echidna)billed platypus and echidna)
§ § Pouched (marsupials)Pouched (marsupials)
§ § Placental (diverse group, including rodents, carnivores, primatePlacental (diverse group, including rodents, carnivores, primates, etc.)s, etc.)
§§ Populations of ancestral mammalians developing independently onPopulations of ancestral mammalians developing independently on diverging landdiverging land
massesmasses
5 When Are We?When Are We?
§ § Mesozoic era (age of reptiles)Mesozoic era (age of reptiles)
§§^ Triassic, Jurassic, and CretaceousTriassic, Jurassic, and Cretaceous
§§ Pangea land mass began splitting during the TriassicPangea land mass began splitting during the Triassic
§ § Mass extinctionMass extinction
§§^ Occurred around the end of the Mesozoic/beginning of CenozoicOccurred around the end of the Mesozoic/beginning of Cenozoic
6 Vertebrate Evolutionary Time ScaleVertebrate Evolutionary Time Scale
7 Mammalian RadiationMammalian Radiation
§ § TherapsidsTherapsids
§§ Intermediate forms b/t reptiles and mammalsIntermediate forms b/t reptiles and mammals §§ Small, endothermic, insectivores animalsSmall, endothermic, insectivores animals
§ § Around this time, these “primitive” mammals are thought to haveAround this time, these “primitive” mammals are thought to have began tobegan to radiateradiate
§§ Adaptive radiation: relatively rapid expansion and diversificatAdaptive radiation: relatively rapid expansion and diversification of an evolving group ofion of an evolving group of organisms as they adapt to new ecological nichesorganisms as they adapt to new ecological niches
2
(^8) The Placental MammalsThe Placental Mammals
§ § Most common groupMost common group § § (^) Distributed all over the worldDistributed all over the world
§§ Flying, swimming, and burrowing (some adaptations)Flying, swimming, and burrowing (some adaptations)
§ § Over 20 orders of mammalsOver 20 orders of mammals
§§^ Range in size from the dwarf shrew (a few grams) to the blue whaRange in size from the dwarf shrew (a few grams) to the blue whale (largestle (largest
animal to known to ever inhabit the earth)animal to known to ever inhabit the earth)
(^9) General Characteristics of Placental MammalsGeneral Characteristics of Placental Mammals
§ § EndothermicEndothermic
§§ Ability to maintain a constant internal body temperature throughAbility to maintain a constant internal body temperature through metabolism (homeothermy)metabolism (homeothermy)
§ § Presence of body hairPresence of body hair
§ § Relatively long gestation period, followed by live birthRelatively long gestation period, followed by live birth
§ § Mammary glands (hence the termMammary glands (hence the term mammalsmammals ))
§ § Increased brain size and moreIncreased brain size and more--developed nervous systemdeveloped nervous system
§ § Increased capacity for learning and behavioral flexibilityIncreased capacity for learning and behavioral flexibility
§ § Different types of teeth (incisors, canines, premolars, and molaDifferent types of teeth (incisors, canines, premolars, and molars)rs)
(^10) PrimatesPrimates
§ § Look at characteristics that, taken together, separate primatesLook at characteristics that, taken together, separate primates from other mammalsfrom other mammals § § (^) Primates have remainedPrimates have remained (^) generalizedgeneralized §§ Retain “primitive” traits that other species have lost over timeRetain “primitive” traits that other species have lost over time, while becoming more, while becoming more specializedspecialized §§^ Example: development of hooves on many prey speciesExample: development of hooves on many prey species §§ Good adaptation for those needing speed and stabilityGood adaptation for those needing speed and stability §§ Lose the ability to manipulate objectsLose the ability to manipulate objects §§^ PrimitivePrimitive^ doesn’t have a inherent value, but that the traits were presentdoesn’t have a inherent value, but that the traits were present in ancestral formsin ancestral forms
(^11) PrimatesPrimates
§ § Because not so specialized, primates can not be described by oneBecause not so specialized, primates can not be described by one or twoor two shared traitsshared traits § § Biologists use a group of traits that, more or less, apply to prBiologists use a group of traits that, more or less, apply to primatesimates
§§ General traits that are not equally represented in all primatesGeneral traits that are not equally represented in all primates
§§^ Expected in a group of related, but diverse, organismsExpected in a group of related, but diverse, organisms
(^12) Primate CharacteristicsPrimate Characteristics
§ § Again, no one feature distinguishes primates from other mammalsAgain, no one feature distinguishes primates from other mammals (except possibly(except possibly
the structure of the middle ear)the structure of the middle ear)
§ § W. E. LeGros Clark (early comparative anatomist and paleoanthropW. E. LeGros Clark (early comparative anatomist and paleoanthropologist)ologist) §§ Defined primates based on evolutionary trends or traits which toDefined primates based on evolutionary trends or traits which together make up the “primategether make up the “primate pattern”pattern” §§^ Most traits related to skeletal morphologyMost traits related to skeletal morphology § § Adaptations reflected in…Adaptations reflected in… §§ Limbs and locomotion, teeth and diet, senses, brain, and behavioLimbs and locomotion, teeth and diet, senses, brain, and behaviorr
(^13) Limbs and LocomotionLimbs and Locomotion
§ § Tendency toward erect postureTendency toward erect posture
§§^ Mostly of the upper bodyMostly of the upper body §§ Shown to some degree in all primatesShown to some degree in all primates §§^ Variously associated with sitting, leaping, standing, and occasiVariously associated with sitting, leaping, standing, and occasional bipedal walkingonal bipedal walking
§ § Flexible, generalized limb structureFlexible, generalized limb structure
§§ Allows for engaging in a variety of locomotor behaviorsAllows for engaging in a variety of locomotor behaviors
4
§ § Acute color vision with increased depth perceptionAcute color vision with increased depth perception
§§ Beneficial for complex, 3D environments with unsure footholdBeneficial for complex, 3D environments with unsure foothold
§ § Ability to grasp with hands and feetAbility to grasp with hands and feet
(^19) Primate Adaptations (cont.)Primate Adaptations (cont.)
§ § VisualVisual--predation hypothesis (Cartmill 1972, 1992)predation hypothesis (Cartmill 1972, 1992) §§ Characteristics such as forwardCharacteristics such as forward--facing eyes occur in other predators (cats, owls, etc.)facing eyes occur in other predators (cats, owls, etc.) §§ Primates may have developed other traits not purely as a responsPrimates may have developed other traits not purely as a response to arboreal environmente to arboreal environment § § (^) Angiosperm hypothesis (Sussman 1991)Angiosperm hypothesis (Sussman 1991) §§^ Primate characters evolved with the emergence of angiosperms (flPrimate characters evolved with the emergence of angiosperms (flowering plants)owering plants) §§ Traits arose due to need for fineTraits arose due to need for fine--tuned visual and tactile discriminationtuned visual and tactile discrimination
(^20) Primate Adaptations (cont.)Primate Adaptations (cont.)
§ § The above hypotheses are likely NOT mutually exclusive!The above hypotheses are likely NOT mutually exclusive!
§§ More likely a combination of these circumstancesMore likely a combination of these circumstances
(^21) Diet and TeethDiet and Teeth
§ § Like majority of other mammals, primates have four types of teetLike majority of other mammals, primates have four types of teethh §§ Incisors and canines: for cutting and bitingIncisors and canines: for cutting and biting §§ Premolars and molars: for chewingPremolars and molars: for chewing § § (^) Dental formulaeDental formulae §§ # of tooth types in any one quadrant of the mouth# of tooth types in any one quadrant of the mouth §§ Most placental mammals have 3:1:4:3 dental formulaMost placental mammals have 3:1:4:3 dental formula §§^ 2:1:2:32:1:2:3——dental formula for adult, Old Worlddental formula for adult, Old World^ anthropoidsanthropoids^ (Old World monkeys, apes, and(Old World monkeys, apes, and humans)humans) §§ 2:1:3:32:1:3:3——dental formula for New World monkeysdental formula for New World monkeys
(^22) Geographic DistributionGeographic Distribution
§ § (^) With some exceptions, nonWith some exceptions, non--human primates are found in tropical and semitropicalhuman primates are found in tropical and semitropical
areas of the Old and New Worldareas of the Old and New World
§ § Majority of primates are arboreal, although some are adapted toMajority of primates are arboreal, although some are adapted to terrestrial habitatterrestrial habitat
(e.g., baboons)(e.g., baboons)
§§ Some spend considerable amount of time on ground (gorillas and cSome spend considerable amount of time on ground (gorillas and chimpanzees)himpanzees) §§ All nonAll non--human primates spend at least some time in the treeshuman primates spend at least some time in the trees
(^23) Primate LocomotionPrimate Locomotion
§§ QuadrupedalismQuadrupedalism §§^ ArborealArboreal §§ FastFast——as in some monkey speciesas in some monkey species §§ SlowSlow——as seen in many prosimiansas seen in many prosimians §§ TerrestrialTerrestrial §§ On fingertipsOn fingertips——as seen in baboonsas seen in baboons §§ KnuckleKnuckle--walkingwalking §§ African great apes (i.e., gorillas and chimpanzees)African great apes (i.e., gorillas and chimpanzees) §§ Vertical clinging and leapingVertical clinging and leaping §§ Slow, quadrumanous climbingSlow, quadrumanous climbing §§ OrangutanOrangutan §§^ BrachiationBrachiation §§ GibbonsGibbons §§^ BipedalityBipedality §§^ HumansHumans
(^24) Next TimeNext Time
§ § Primate classificationPrimate classification § § Comparative anatomy of mammals with respect to locomotionComparative anatomy of mammals with respect to locomotion
5
§ § Overview of the extant primatesOverview of the extant primates
