Topic 34: humans

Question 1

_____ is the only extant species of genus homo

Answer 1

Homo sapiens

Question 2

Are Humans great apes?

Answer 2

yes

Question 3

closest living relatives to humans

Answer 3

chimpanzee and bonobo

Question 4

Clade Hominins includes

Answer 4

chimpanzees and bonobos, and humans and their extinct relatives

Question 5

Humans differ from other extant great apes (Hominids) in

Answer 5

1. Upright posture and bipedal locomotion.
2. Larger brains
3. Reduced jawbone and jaw muscles.
4. Shorter digestive tract

Question 6

Trends in hominin evolution

Answer 6

- Bipedalism (early).
− Expansion of the brain (cranial capacity) and increased brain complexity (later).
− Modification of the pelvis.
− Reduction of teeth, face, and jaws.
− Extended period of infant and child dependency
- Increasing hairlessness.
− Increased reliance on meat.
− The emergence of tool use

Question 7

challenges that favored natural selection for bipedalism

Answer 7

• Large mammals predators.
  − Competition from terrestrial primates.
  − Decline in arboreal habitats, and expansion of open grasslands

Question 8

Advantages of bipedalism

Answer 8

− Increased ability to see predators and prey.
− Energy-efficient locomotion, especially for long-distance travel.
− Better thermoregulation in open habitats
- Frees hands for carrying food and infants, and for tool use

Question 9

restructuring of anatomy for bipedalism

Answer 9

spinal curved like S, pelvis, legs longer, and skull attachment, foot (larger heel and larger big toe)

Question 10

foramen magnum

Answer 10

repositioned so that the human skull balances directly on top of the vertebral column

Question 11

Australopiths

Answer 11

paraphyletic assemblage of hominins living between 4–1.5 mya, fully bipedal, short and had sexual dimorphism, some tool use

Question 12

Homo habilis

Answer 12

Simple stone tools, 2.4–1.6 mya

Question 13

Homo ergaster

Answer 13

first fully bipedal and large-brained hominin (lived between 1.9–1.5 mya), first to live in hunter-gatherer society

Question 14

the first hominin to leave Africa

Answer 14

Homo erectus

Question 15

Homo heidelbergensis

Answer 15

Homo erectus in Africa gave rise to Homo heidelbergensis, similar to humans in body, sophisticated tool use,

Question 16

Neanderthals and Homo sapiens both evolved from

Answer 16

Homo heidelbergensis

Question 17

Neanderthals

Answer 17

Lived in Europe and Near East, Were cold-adapted hominins with stout physiques

Question 18

Denisovans

Answer 18

• were a genetically distinct group of Homo that lived in Eurasia about 50 kya
• Denisovans interbred with Neanderthals and ancestors of some modern humans

Question 19

Homo sapiens

Answer 19

large brains, a broader set of tools and hunting techniques, first to have artistic thought

Question 20

Human migration out of Africa happened

Answer 20

200 kya

Question 21

What proof do we have that humans arose in Africa

Answer 21

mitochondrial DNA (mtDNA)