Final exam

Question 1

Rainforest Ecology

Answer 1

The rainforest offers three vertical niches:
1. the crown or top layer
2. the canopy
3 .the understory
All are complex habitats but the crown & canopy provide uncertain footholds for animals seeking food. Hunting & foraging in these top layers require good vision; a variety of locomotor abilities (climbing, leaping, grasping); memory (to know when & where certain food is available) and other forms of intelligence. Available food includes leaves, fruit, seed, nuts, flowers, nectar, pollen, bird eggs, insects, gum or sap, small mammals & snakes & other reptiles.

Question 2

Arboreal adaptation

Answer 2

1. Grasping hands & feet
2. Nails instead of claws (with some exceptions) – this is arguable. See below
3. Stereoscopic vision in order to perceive depth when leaping from tree to tree
4. Color vision
5. Omnivory (ability to eat everything that’s edible)
6. Generalized dentition (meaning different types of teeth – incisors, canines, premolars & molars)
7. Behavioral flexibility that made it possible to exploit a variety of niches
8. Brain capacity to learn, interpret information

Question 3

Visual Predation

Emphasizes the demands of life in the bushy undergrowth , where the light is dim. Life in the undergrowth required

Answer 3

1. forward-facing, close-set eyes with good vision to spot & catch insects
2. grasping hands & reduced claws to make it possible to creep up narrow tree limbs to catch prey
3. fine sense of touch & precision grip (as a response to the dim light)
4. reduction of the sense of smell (since forward eye placement leaves less room for a long snout)
5. brain complexity for locating & manipulating small food items in dim light

Question 4

Flowering angiosperm – emphasizes the new opportunities presented by the emergence of plants producing flowers some 65 mya. Along with flowers came a new abundance of insects, flower buds, nectar, pollen, seeds, fruits, leaves. Eating these required:

Answer 4

1. Good vision to find small food items amidst branches & identify younger, more tender leaves
2. Grasping hands & feet to cling to the small branches , where flowers are most likely to be
3. Fine sense of touch to test fruits for ripeness – important because ripe fruits provide more Vitamin C, higher sugar content, quick energy

Question 5

Difference between anthropoids and prosimians

Answer 5

They have a smaller brain relatively to body size than anthropoids
Their eyes are relatively larger and placed more laterally (to the side) on their heads
A postorbital bar, rather than a full bony cup, lies behind their eyes, resulting in less protection for the eyes than anthropoids have
Their molars have high, pointy cusps to allow them to crunch through the hard exoskeletons of insects
Their canine teeth are relatively smaller compared to their skull size than anthropoids’ canines
Prosimians other than the tarsier have a “toothcomb” – or “dental comb” – lower incisors that are compressed together and protrude. The toothcomb is used as a grooming tool, for cleaning their own and others’ fur
They have a split upper lip and a unfused mandible (lower jaw), making it impossible for them to change their facial expression and therefore reliant on vocalizations and their sense of smell to communicate
They have a grooming claw, in contrast to anthropoids, whose fingers all have nails
They generally move through the trees by leaping vertically and clinging
They don’t have an opposable thumb and are therefore not capable of the precision grip that characterizes anthropoids
Several species are monogamous (a family structure that’s relatively rare among non-human primates – tarsiers, Indris (a type of lemur) and possibly pottos
non-human primates – tarsiers, Indris (a type of lemur) and possibly pottos