Chapter 12 - Human Changes Over Time

Question 1

Humans

1. Humans are?
2. Humans:
   • Phylum
   • Class
   • Order

• 5 MYA, ancestors diverged

Answer 1

1.
• Eukaryotes 
• Members of the animal kingdom
• mammals
• primates
• part of the great apes family
2.
• chordata 
• mammalia
• primates

Question 2

2 mammal characteristics

Answer 2

1. Milk-producing mammary glands

2. Lower jaw made of one bone

Question 3

Primates

1. 4 characteristics
2. • Phylum
   • Class
   • Order
   • Super-family

Answer 3

1.
• Opposable thumbs
• stereoscopic vision (3D vision)
• Larger brains relative to body size
• Social mammals
• relatively long gestation periods

2. 
• Chordata
• Mammalia
• Primates
• hominoidae

Question 4

Hominoid

1. Is?
2. Also includes?
3. Monkeys or not monkeys?
4. 3 characteristics

Answer 4

1. Members of the biological superfamily Hominoidae, to which hominins and ALL APES belong (e.g. gorillas, chimps, humans, orangutans, gibbons).
2. Also includes gibbons, chimps, gorillas, orangutans.
3. Not monkeys - don’t have tails and have a wide chest.
4. • brain is larger and more complex
   • Y5 pattern on molar teeth in the lower jaw
   • relatively broad palates and broad nasal regions

Question 5

Hominin

1. Is?
2. ~pedal?

*first level of classification that humans are separated from all other great apes

Answer 5

1. The group consisting of modern humans, extinct human species and all other immediate ancestors (including members of the genus Homo, Australopithecus, Paranthropus and Ardipithecus).
2. Bipedal

Question 6

Hominid

1. Is?

Answer 6

The group including all modern and extinct Great Apes (e.g. humans, chimps, gorillas, orangutans) 
Excludes gibbons (and lesser apes).

Question 7

Hominin evolution

1. Four originally recognised genera in the type known as hominins (human-like)
   * debate whether hominins evolved from Asia or Africa

Answer 7

1. Sahelanthropus - oldest known fossil, not everyone agrees.
2. Australopithecus - fully bipedal, arms longer than legs, hands like humans, brain was smaller, no evidence of tools.
3. Paranthropus - like Australopithecus, but used tools.
4. Homo - less heavy bones, larger brain case, reduced size of the jaws, used stone tools, beginning of cultural evolution.

Question 8

Hominin evolution / differences between hominins and hominoids

Hominin | hominoid

Answer 8

• definitions
• S-shapes spine | slightly curved spine
• arms shorter than legs and not used for walking | arms longer than legs and used for walking
• wide, bowl-shaped pelvis | long, narrow pelvis
• femur and tibia angled inward (outward slant) | femur and tibia straight line arrangement
• increase average brain case capacity | smaller brain case capacity
• foramen magnum in the middle of skull | foramen magnum back of the skull
• bipedal | quadrupedal

*skull = flatter, bigger cranial capacity, position of foramen magnum, size of brow ridge.

Question 9

Foramen magnum

1. Define
2. Indicates?

Answer 9

1. The hole at the bottom of the cranium where the spinal cord leaves the brain and enters the vertebral column (backbone).
2. How the skull sat in the vertebral column. Centre = organism walks upright, back of the skull = organism walks stooped on all fours.

Question 10

The beginning: the prehuman hominins

Prehuman hominin fossils can be organised into 4 groups.
What are the 4 groups?

Answer 10

1. The Australopithecines
2. The robusts - Paranthropus (heavily built skulls, heavy brow ridges and very large premolar and molar teeth)
3. The Ardipithecines
4. The ‘oldies’ = earliest of the prehuman hominins

Question 11

The genus Homo

1. Earliest human species generally accepted?
2. 7 characteristics?
3. Other species agreed on?

Answer 11

1. Homo habilis
2. Bipedal, flat face, lack heavy brow ridges, large cranial capacity, use art and language, make and use fire, bury the dead.
3. H. erectus, H. heidelbergensis, H. neanderthalensis, H. sapiens.

Question 12

The genus Homo

1. Homo habilis
2. Homo erectus
3. Homo floresiensis
4. Homo heidelbergensis
5. Homo neanderthalensis
6. The Denisovans

Answer 12

1. Stone tools - suggests habilines were the first hominins to purposefully struck stone flakes off pebbles to create sharp/edged flakes, knives, cutters, scrapers, hunting, protection.
2. Fossils found in other parts of the world - they migrated out of Africa, controlled and used fire, more elaborate tools, systematic hunting.
3. Small in stature, small brain capacity, made tools and used fire.
4. Believed to be the intermediate species between Homo erectus and Homo sapiens.
5. • Large brains, inner ear bones different, short and strongly built.
   • Existed in Europe and Middle East over about 200,000-300,000 YA.
   • Evolved from Homo erectus.
   • Crafted fine tools, ornaments
   • Lived in caves, made clothing, built shelters
   • 1-4% of DNA of all non-African modern humans today come from Neanderthals = Neanderthals and modern humans must have interbred at some point.
6. 2008, Denisova cave, tiny finger bone from a human female - DNA did not match Neanderthals or modern humans = new human group that coexisted with Neanderthals and modern humans.