chapter 11 (becoming human)

Question 1

taxon

Answer 1

a unit of biological classification into which related organisms are classified

Question 2

mammals

Answer 2

• warm-blooded vertebrates belonging to the taxonomic class mammalia
• key characteristics: mammary glands, hair/fur, three middle ear bones, and one lower jawbone.

Question 3

primates

Answer 3

• such as orangutans, lemurs, baboons and gorillas
• key characteristics: 3D colour vision, sensitive touch receptor fingertips, prehensile hand and opposable digits, flexible spines and rotation of hips and shoulders

Question 4

hominoids

Answer 4

• greater apes: orangutans, chimpanzees, gorillas and humans - lesser apes: many different species of gibbons
• key characteristics: shorter spine, lack of tail, molar teeth, longer arms than legs, shoulder blades further back, arms swing behind the head

Question 5

hominins

Answer 5

separates humans from primate relatives such as chimps and gorillas is the ability to walk on hind legs over a sustained period of time this is known as bipedalism

Question 6

compare gorilla to homo sapien

Answer 6

• canine teeth: humans have smaller canine teeth
• foramen magnum: is more central is human skull
• brow ridge: humans have smaller brow ridge
• sagittal crest: absent in humans
• spine curve: gorillas have C shaped and humans have S shaped
• rib cage: humans is more barrel shaped and gorillas are more funnel shaped
• hand: humans have refined precision grip
• pelvis: humans are more shallow and bowl shaped and other primates are more long and narrow
• femur angle: humans have relatively large femur angle
• foot: human feet no longer have prehensile capabilities.

Question 7

hominin evolution

Answer 7

• large brain size: brain size has tended to increase overtime (hominin brains tend to be more folder increasing total surface area)
• smaller arm to leg ratio: longer legs are more energy efficient for bipedalism
• changing pelvis shape: narrower and more bowl shaped pelvis

Question 8

Interbreeding between homo sapiens and neanderthals

Answer 8

• 1-4% of the DNA of all non-african modern humans is identical to H.Neanderthals DNA, indicating that once H.sapiens migrated out of africa they interbred with the neanderthals in Eurasia around 65,000.
• The H.sapiens which stayed in africa do not have any neanderthals DNA as they did not inhabit in the same regions and the same time.

Question 9

fossil record used to demonstrate relatedness

Answer 9

comparative anatomy such as the presence of homologous structures

Question 10

molecular homology used to demonstrate relatedness

Answer 10

similarities between nucleotides in DNA sequences or amino acid sequences as evidence for relatedness

Question 11

multiregional hypothesis

Answer 11

a model for the geographical spread of Homo sapiens which suggests that separate human populations evolved independently from earlier hominins that had spread throughout Eurasia and experienced gene flow

Question 12

out of africa hypothesis

Answer 12

a model for the geographical spread of Homo sapiens which suggests that humans first developed and evolved in Africa before migrating outwards and expanding their colonies replacing the earlier hominins that had spread prior.
(link with mitochondrial DNA)

Question 13

aboriginal and torres strait islander connection

Answer 13

• ‘Country’ is a special relationship between individuals and their ancestral land
• Dreaming: aboriginal philosophy that describes when ancestral spirits moved over the land and created life and geographical sites
• the out of africa hypothesis diminishes the traditions views of many first nations people and communities.