Characteristics of Primates- Cerebral Cortex and Gestation (17)

Question 1

What are functions of the cerebral cortex

Answer 1

o Higher functions- vision, memory, reasoning, manipulative ability
o Functions necessary to cope with changes in environment

Question 2

Explain trend in brain

Answer 2

• an expansion and reorganization of the brain with resultant consequences for behavior

Question 3

Why are primate brains large for their body size

Answer 3

o consequence of their tree dwelling environment
o Pressure of natural selection in arboreal environment= favor more accurate vision, tactile perception, better coordination b/w such sensory stimuli and any muscular response
o Unlike smell or hearing, reliance on vision to move about, locate and manipulate food generates large amount of complex sensory information that has to be processed and stored
o In primates= such functions by cerebral cortex
o Progressive expansion of cerebral cortex resulted in becoming so large it covers rest of brain, most noticeable in humans

Question 4

What has caused the increase in convolutions

Answer 4

o Enable SA of brain and hence cerebral cortex, to greatly increase
o Through species= larger cerebrum + more convoluted
o Convolutions= 50% increase in SA of human brain compared to no convolutions

Question 5

What (3) has increased size in cerebral cortex allowed

Answer 5

• enable to locate food
• develop special skills (tool making)
• Greater variety of behavioral responses to meet wide array of environmental problems (interaction, relationships)

Question 6

what has taken place of further physical specialisation

Answer 6

behavioural flexibility

Question 7

why single offspring

Answer 7

arboreal life= carrying through trees

Question 8

what sort of mammals (in terms of pregnancy) are primates?

Answer 8

placental, offspring developing inside mothers body from nourishment from placenta

Question 9

how efficeint are primate placentas compared to other mammals and what does it allow

Answer 9

have more efficient placenta allowing closer contact between mothers blood supply and developing offspring

Question 10

explain the time of gestation

Answer 10

• remarkably long

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Question 11

when the primate offspring is born, how much care do they require

Answer 11

• offspring more developed are more immature, requiring much care and protection

Question 12

Explain the period of parental care of primates

Answer 12

• period of parental care can be more protracted

o Length of this period increases with the progression from lemurs through to monkeys apes and humans

Question 13

explain the associated delay in maturation (long period of growth and development) with period of parental care

Answer 13

o Result= sexual maturity is attained much later in apes and human than lemurs and monkeys
o Fact that apes and humans have such an importance facet of a primates life as it enables ideas and techniques to be passed on from one generation to the next

Question 14

why do females usually only have on offspring in lifetime

Answer 14

Delay in maturation and late arrival of sexual maturity

Question 15

what does one offspring (usually) per female result in

Answer 15

o Makes each offspring particularly important, and considerable time and effort is invested in their care and survival
o Investment in prolonged parental care evolved because increases survival chances of offspring and provides a long period during which the young can learn from older members of the group