Introduction (1)

Question 1

Since the ________ revolution, we have come to see ourselves as a result of several ______ years of earth’s history rather than a _______ life form unrelated to other organisms on the planet.

Answer 1

Darwinian
billion
unique

Question 2

What ‘order’ do humans belong to?

Answer 2

Humans are mammals and members of the mammalian order known as primates .

Question 3

How many species make up the primates?

Answer 3

The order primates with its 300 or more species , is the third most diverse order of mammals , after rodents and bats .

Question 4

What characteristics show that primates have common ancestry?

Answer 4

anatomical and functional characteristics showing their common ancestry, which had its beginning about 85 million years ago .

Question 5

What evidence is there that primates have a common ancestor?

Answer 5

There is biogeographical evidence of a common ancestor as all wild primates are found in lands that previously were part of the southern continent, Gondwanaland.

Question 6

What played an important part in the initial geographical subdivisions within primates?

Answer 6

If the latest research which indicates that primates originated about 85 mya is correct, then continental drift, which broke up the super continent Gondwanaland (about 180 to 200 mya), probably played an important part in initial geographical subdivisions within primates.

Question 7

What are most present-day primates?

Answer 7

Most present - day primates are arboreal, i.e. living in trees; this characteristic suggests that they evolved from an ancestor that was arboreal.

Question 8

Many, especially the ____ world monkeys of _____America, have remained totally ________ while others have become at least partly ________ e.g. baboons (one of the old world primates).

Answer 8

new
South
arboreal
terrestrial

Question 9

What adaptations are a result of this arboreal way of life?

Answer 9

They have kept the clavicle or collarbone, which forms an important part of the shoulder joint.

Question 10

What has this clavicle bone allowed for primates to do?

Answer 10

This bone helps to stabilise the shoulder, allowing a primate to support its weight by hanging from its arms alone - something that few other mammals can do.

Question 11

What other adaptations do primates have?

Answer 11

They have long, slender limbs that rotate freely at the shoulders and hips.

Question 12

What does long, slender limbs allow for?

Answer 12

This helps their movement in the trees.

Question 13

What adaptation do primates have for their thumbs?

Answer 13

Many have mobile opposable thumbs.

Question 14

What group of primates have dextrous hands?

Answer 14

It is only the catarrhines (Old World monkeys, apes, and humans) and a few of the lemurs and lories that have dextrous hands.

Question 15

it is only some of the ____ world primates that have a ________ tail. “Hands with an _______ thumb and _____ fingers are able to grasp and hold on to branches effectively.

Answer 15

new
prehensile
opposable
separate

Question 16

What brain adaptation do primates have?

Answer 16

An enlarged and complex brain relative body size.

Question 17

What face adaptation do primates share?

Answer 17

A flattened face and reduced snout with reduced sense of smell. This is possibly because primates have come to rely on vision more than on smell.

Question 18

What eye adaptation do primates have?

Answer 18

Eyes that face forward so that the eyes visual fields overlap to give stereoscopic vision.

Question 19

What nail adaptation do

Answer 19

Digits with flat nails. All other mammals have claws or hooves on their digits. Nails probably allowed for manipulation that is more sensitive.

Question 20

What teeth adaptation do primates have?

Answer 20

molar and premolar teeth with cusps that are low and rounded. Other placental mammals have high, pointed cusps or elaborate ridges. This distinction makes fossilized primate teeth easy to recognize.

Question 21

What social behaviour do primates exhibit?

Answer 21

complex social behaviour, usually only one offspring at a time and extended care for the young.

Question 22

Genetic evidence of a common ancestor for primates is slowly emerging. Primates: (3)

Answer 22

• share a large percentage of their DNA. It is well known that humans share about 98.5% of their DNA with chimpanzees and 93% with rhesus monkeys. This suggests that they must have had a common ancestor at some stage.
• have a larger number of olfactory-receptor pseudo-genes than non-primates. This is consistent with the deterioration of the sense of smell in primates. Humans have about 60% and non-human apes 30% more pseudo-genes than non-primate mammals. pseudo-genes = remnants of genes that are no longer functional
• have full trichromatic colour vision (ability to perceive red, green, and blue), which is found only in the primate order, e.g. humans, apes and old-world primates. These primates all have the same opsin genes that provide this type of vision.