Hominins

Question 1

Hominoid

Answer 1

• includes all hominins, hominids, and lesser apes like siamangs and gibbons
• all hominins are hominids
• all hominids are hominoids

Question 2

Hominid

Answer 2

• quadrupeds
• group consisting of all modern and extinct great apes and all hominins
• monophyletic group

Question 3

Hominin

Answer 3

• group consisting of modern humans, extinct human species
• all our immediate ancestors
• smaller subset of hominids
• bipeds

Question 4

Great ape

Answer 4

• any of several large primates (including the orangutan, gorilla, chimpanzee, and bonobo) that are closely related to humans

Question 5

Anthropoids
explain what makes them different from prosimians

Answer 5

• include monkeys and apes with a fully opposable thumb
• constitute a monophyletic group

Question 6

Prosimians

Answer 6

• primitive primates that are smaller in size (includes lemurs, lorises, pottos, bushbabies, and tarsiers)
• constitute a paraphyletic group

Question 7

Old World Monkeys
examples?

Answer 7

• africa and asia
• evolved first
• lack a prehensile tail
• nostrils that open downward
  ex. mandrill baboon, macaque, mangabey, proboscis monkey

Question 8

New world monkeys
examples

Answer 8

• have a prehensile tail (adapted to grasp or hold objects)
• nostrils that are wide open and further apart
  ex. emperor tamarin, common marmoset, capuchin monkey

Question 9

Apes

Answer 9

• lack a tail
• relatively long arms and short legs
• larger brains with respect to body size
• more flexible behavior

Question 10

4 main genera of the hominin lineage
order from oldest to recent

Answer 10

Ardipithecus - Australopithecus - Paranthropus - Homo group

Question 11

List and describe trends hominin skull development

Answer 11

• increase in cranial capacity
• decrease in prominence of brow ridges
• decrease in sagittal (cranial) crest
• reduced canine size
• prognathism decreased
• positioning of foramen magnum from posterior towards the base of skull

Question 12

Benefits of upright posture

Answer 12

• hands were free: tools, weapons, food gathering
• walking/running on two legs: travel great distance (less energy)
• visibility of surrounding was greater
• birth canal more narrow: helped to better support inner organs
• helps to dissipate excess body heat and reduces absorption of heat from sun, less skin has a direct exposure to uv radiation during hot times of day

Question 13

When did earliest primates evolve

Answer 13

50-55 million years ago

Question 14

When was the last common ancestor that humans had with chimpanzees

Answer 14

• lived about 6-7 million years ago