Presentation on theme: "12.6 Primate Evolution KEY CONCEPT Humans appeared late in Earth’s history."— Presentation transcript:
12.6 Primate Evolution KEY CONCEPT Humans appeared late in Earth’s history.
12.6 Primate Evolution I. Humans share a common ancestor with other primates. A. Primate Characteristics 1. Moveable fingers and toes 2. Flat nails 3. Prehensile (grasping) hands 4.Color vision 5.Front facing eyes 6.Enlarged brains
12.6 Primate Evolution B. Primates evolved into prosimians and anthropoids. 1.Prosimians are the oldest living primates a.They are mostly small and nocturnal b.Examples: lemurs, lorises, tarsiers
12.6 Primate Evolution 2. Anthropoids are humanlike primates.
12.6 Primate Evolution a. Characteristics of Anthropoids –Well developed collar bone –Rotating shoulder –Dental formula (molars, premolars, canine, incisors) –Opposable thumbs
12.6 Primate Evolution 1.New World Monkeys: Marmosets, Howlers, Spider Monkeys, Squirrel Monkeys a.All live in trees b.Many have prehensile tails C. Anthropoids are subdivided into the New World monkeys, Old World monkeys and hominoids
12.6 Primate Evolution 3. Hominoids – Orangutans, Bonobos, Chimps D.Hominoids are divided into hominids, great apes and lesser apes 1. Hominids include living and extinct humans a. Walk upright b. Have long lower limbs c. Opposable thumbs d. Relatively large brains 2. Great apes include gorillas, chimps and orangutans 3. Lesser apes include gibbons
12.6 Primate Evolution E. Walking Upright (a characteristic of humans) 1. Bipedal means walking on two legs which allows… a.Foraging b.carrying infants and food c.using tools 2.Requires: a. Cup shaped pelvis b. S shaped spine c. Toes aligned d. Larger brain
1. Most hominids are classified either as Australopithecus or Homo 2. Australopithecines were a successful genus a. Australopithecinus afarensis i. Lived 3 – 3.9 million years ago ii. Cranial Capacity is 1/3 of modern humans iii. Humanlike limbs II. There are many fossils of extinct humans Australopithecus afarensis Homo habilisHomo neanderthalensis Homo sapiens
3. The Homo genus first evolved 2.4 million years ago a. Homo habilis i. Lived 2.5 – 1.6 mya ii. “Handy man” – used tools iii. Ate meat iv. Speech Australopithecus afarensis Homo habilisHomo neanderthalensis Homo sapiens
Australopithecus afarensis Homo habilisHomo neanderthalensis Homo sapiens b. Homo Neanderthalensis i. “Neanderthals” ii. Larger cranial capacity than humans iii. Thick brow ridges and protruding teeth iv. Tools v. Wore Clothing vi.Buried their dead vii.Replaced by modern humans
III. Modern humans arose about 200,000 years ago 1. Homo sapiens fossils date to 200,000 years ago a. Human evolution is influenced by a tool-based culture b. There is a trend toward increased brain size in hominids c. Characteristics: i. High forehead ii. No brow ridge Australopithecus afarensis Homo habilisHomo neanderthalensis Homo sapiens