Characteristic Trends Primates Summery (17)

Question 1

Digits- Mobility Trend

Answer 1

Increasing mobility and ability to move more digits independently of one another

Question 2

Digits- Opposability Trend

Answer 2

First digit opposable and increasing length= increasing effectiveness of opposability

Question 3

Digits- Claws/Nails Trend

Answer 3

Primitive primates retain claws on some digits; higher primates= nails on all digits

Question 4

Dentition Trends in number of teeth

Answer 4

36 Teeth in lemurs, lorises and New World monkeys

32 in old world, apes and humans

Question 5

Dentition trends in cups

Answer 5

4 cusps in monkeys

5 in apes and humans

Question 6

Dentition trends in diastema

Answer 6

Monkeys and apes= large projecting canines with diastema

Question 7

Trend in Smell

Answer 7

sense of smell reduced with gradual reduction in length of snout

Question 8

Vision- Eyes Trend

Answer 8

Increased efficiency in vision

eyes becoming forward facing= stereoscopic vision

Question 9

Vision- Eye Socket Trend

Answer 9

gradual becoming enclosed in protective bony socket

Question 10

Vision- Visual area of the brain Trend

Answer 10

increasing proportion of cerebrum devoted to vision

Question 11

Brain- Convolutions Trend

Answer 11

increase in # of folds in surface over cerebrum

Question 12

Brain- Size Trend

Answer 12

increase size of brain relative to size of body

Question 13

Brain- Cerebral Cortex Trend

Answer 13

cerebral cortex making up an increasing large proportion of the brain

Question 14

Gestation Trend

Answer 14

increasing length of time between fertilisation and birth

Question 15

Development- Dependance Trend

Answer 15

increase length of time offspring dependant on parents

Question 16

Development- Sexual Maturity Trend

Answer 16

increasingly later development of sexual maturity