Lecture 36 Amniotes - Humans

Question 1

what is the superfamily of apes?

Answer 1

hominoidea – hominiods

Question 2

what are hominoids?

Answer 2

lack tails, relatively large brains, includes gibbons (lesser apes), hominid great apes (orang, gor, chimp, bonobos humans)
- monophyletic group

Question 3

what are hominids?

Answer 3

hominidae - great apes – orang, goril, chimps, humans

Question 4

what are hominines?

Answer 4

homininae - goril, chimps, humans

Question 5

what are hominins?

Answer 5

hominini - modern humans and extinct relatives

Question 6

what are the closest living relatives to Homo?

Answer 6

chimpanzees and bonobos

- extinct hominins are more closely related to humans than to chimps

Question 7

what are the derived characteristics of humans?

Answer 7

• upright posture and bipedal locomotion
• larger brains
• reduced jawbones and jaw muscles
• shorter digestive tract (omnivore instead of herbivore)

Question 8

where did hominins originate?

Answer 8

africa 6-7MYA

Question 9

what are trends in hominin evolution?

Answer 9

• bipedalism
• expansion of brain and increase in brain complexity (later)
• modification in female pelvis
• reduction of teeth, face, jaws
• extended period of infant and child dependence
• hairlessness
• increased reliance on meat
• emergence of tool use

Question 10

what changes occurred with bipedalism?

Answer 10

• changes in knee, foot (big toe), pelvis, spine curvature, skull attatchment

Question 11

what is the best hypothesis of bipedalism?

Answer 11

• energy efficiency

- thermoregulation

Question 12

what are australopiths

Answer 12

paraphyletic assemblage of early hominins

• bipedal: bowl shaped pelvis
• diminutive
• large degree of sexual dimorphism
• small brain
• relatively large and jutting jaw
• 44yr life expectancy
• robust paranthropus – sturdy skulls and powerful jaws
• gracile – more slender, lighter jaws: ancestors of modern humans

Question 13

what are trends in hominin evolution?

Answer 13

• bipedalism
• expansion of brain and increase in brain complexity (later)
• modification in female pelvis
• reduction of teeth, face, jaws
• extended period of infant and child dependence
• hairlessness
• increased reliance on meat
• emergence of tool use
• increased cranial capacity
• tool use

Question 14

what are australopiths

Answer 14

paraphyletic assemblage of early hominins

• bipedal: bowl shaped pelvis
• diminutive
• large degree of sexual dimorphism
• small brain
• relatively large and jutting jaw
• 44yr life expectancy
• robust paranthropus – sturdy skulls and powerful jaws
• gracile – more slender, lighter jaws: ancestors of modern humans

Question 15

what is the earliest homo species?

Answer 15

• H. habilis – handy man, had shorter jaws, larger brain capacity, less diminutive

Question 16

what was homo ergaster?

Answer 16

first fully bipedal, large brained hominin

• larger brain than habilis
• long slender legs, hip joints suited to long distance walking
• smaller teeth (ate more meat, less grinding of plants)
• more sophisticated tool use
• significant decrease in sexual dimorphism (pair bonding?)

Question 17

what was homo erectus?

Answer 17

• first hominin to leave africa
• likely first to live in hunter gatherer society gave rise to Homo heidelbergensis – led to Neanderthals and H. sapiens

Question 18

what were neanderthals?

Answer 18

H. neanderthalensis

• cold adapted hominins with stout physiques, complex behaviours (buried dead, hunting tools), brains similar in size to humans
• lived alongside H. sapiens

Question 19

where did all living humans descend from?

Answer 19

african ancestors (H. heidelbergensis)

Question 20

what hypothesis does this course support?

Answer 20

out of africa hypothesis

-supported by mtDNA