Lab 6: Primate Classification

Question 1

Taxonomic classification

Answer 1

System of comparing groups of organisms based on homologies (similarities that are shared due to common ancestry) and analogies (traits that arise via convergent evolution).

Question 2

shared derived traits

Answer 2

Traits that have evolved and link together a group of organisms (exp having forward facing eyes links together/distinguishes monkeys from dogs)

traits shared by two or more taxa and their most recent common ancestor to the exclusion of all other earlier and contemporaneous groups.

Question 3

Taxonomy: Domains and Kingdoms

Answer 3

broadest, most encompassing taxonomic levels used to group organisms sharing general features in common

There are 3 domains and 6 kingdoms

Question 4

Taxonomy: Phyla

Answer 4

less broad classification than domain or kingdom

Subcategories of domains and kingdoms

Plural is phyla

Question 5

Taxonomy: Classes

Answer 5

Subgroups of phyla

Question 6

Taxonomy: Orders

Answer 6

Subgroups of classes organized into families

Question 7

Taxonomy: Genus

Answer 7

A subgroup of families

Plural is genera

Question 8

Taxonomy: Species

Answer 8

Subgroup of Genus

Question 9

The biological species concept

Answer 9

The idea that members of a species are recognized as a reproductively isolated group of organisms

Question 10

Reproductive isolation

Answer 10

refers to geographic, behavioral, morphological, and/or genetic differences between species that prevent them from commonly producing fertile, viable offspring in the wild.

Question 11

Primate Classification: Gradistic classification

Answer 11

1 of 2 types

older version that uses the suborder names Prosimian and Anthropoid. Prosimians include lemurs, lorises, galagos, and tarsiers while Anthropoids include New World monkeys, Old World monkeys, apes and humans.

Question 12

Primate Classification: Cladistic classification

Answer 12

1 of 2 types
uses the suborders Strepsirhini and Haplorhini. The biggest difference is that tarsiers are categorized with monkeys, apes and humans under Haplorhini instead of with lemurs, lorises and galagos under Strepsirhini. For this lab, the Cladistic classification is used

Question 13

Strepsirhines

Answer 13

1 of 2 suborders of primates

live in isolated regions of Africa and Asia.

includes lorises and galagos and all species of lemur

retained a grooming claw on the second digit of each of their hind feet.

possess a dental tooth comb made up of the lower incisors and canines, which projects forward horizontally from the mandible.

Some are nocturnal and possess a tapetum lucidum (a layer in the retina of the eye reflects light)

possess a postorbital bar like all primates, but lack the full postorbital closure characteristic of most haplorhine primates

most strepsirhines rely more heavily on olfaction than do haplorhines, as is reflected in their large nasal cavities and more pronounced snouts.

Question 14

Lemurs

Answer 14

Part of Strepsirhines suborder

diverse taxonomic group, accounting for at least 13% of all primate species in the world.

Question 15

Haplorhines

Answer 15

1 of 2 suborders of primates

Rely on visual sensory systems over olfactory systems

habitually diurnal (awake during the day) lifestyles

skull differs from that of strepsirhines in several ways: highly developed postorbital (aka postorbital closure), paired frontal bones are fused together as are the two halves of the mandible

relatively large brains

socially complex/shares a wide variety of social organizations and adaptations to local environments.

able to learn from conspecifics that corresponds to this greater brain size relative to body size.

diverse/inhabit a wider geographical range than the strepsirhines.

Question 16

Tarsiiformes

Answer 16

Subset of Haplorhines

located in Southeast Asia

possess features characteristic of both strepsirhines (e.g., a grooming claw) and haplorhines (e.g., postorbital plate, shortened snout length, no tooth comb).

Question 17

Platyrrhines

Answer 17

Subset of Haplorhines

include all Central and South American monkeys (aka New World monkeys (NWM))

arboreal

small- to medium-bodied

on average weigh 100 g to 10 kg.

external nostrils are typically broad and flat.

possess three premolars and so exhibit a 2-1-3-3 dental formula. Marmosets and tamarins are one exception to this dental formula, having only 2 molars per quadrant.

Some possess a prehensile (grasping) tail that enhances their ability to move through their arboreal environments.

Question 18

Catarrhines

Answer 18

Subset of Haplorhines

comprised of the superfamilies Cercopithecoidea (all Old World monkeys) and Hominoidea (apes and humans).

both arboreal and terrestrial taxa

typically larger-bodied than platyrrhines

named for their downward facing, typically narrow external nostrils

only have two premolars in each quadrant of the mouth leading to a 2-1-2-3 dental formula and have diastema (gap) between their lower canine and lower third premolar.

Question 19

Cercopithecoidea

Answer 19

Subset of Catarrhines, which are subsets of Haplorhines

more diverse and numerically more abundant than the hominoids (except for humans)

Old World monkeys (OWM) are found throughout Africa and Asia,

Old World monkeys possess specialized bilophodont molar teeth in which the two anterior and posterior cusps of the molar are aligned to form two ridges, or lophs

broken down into the Cercopithecinae and Colobinae subfamilies, both of which are represented in Africa and Asia.

highly-adapted folivores, or leaf-eaters.

sharp-cusped cheek teeth and a sacculated stomach (divided into sections) where leaves and seeds are digested by gut bacteria.

adapted for diets comprised primarily of seeds and fruits.

possess blunter cusps on their molars and larger incisors than the colobines.

possess cheek pouches where they store unripe fruits and seeds.

Question 20

Hominoidea.

Answer 20

Subset of Catarrhines, which are subsets of Haplorhines

second superfamily within the catarrhines.

comprised of apes and humans

possess molars that have rounded cusps rather than the bilophodont crests of the cercopithecoids.

lower molars of apes and humans have a distinct Y-5 pattern: five cusps separated by a pronounced Y-shaped groove

do not possess a tail.

The lesser apes are smaller with narrower trunks than the great apes

All (except us) have long arms that are adaptive for their different modes of locomotion

large brains relative to their body size, and typically considered the most behaviorally complex of the primates.

Question 21

Primitive Traits

Answer 21

Traits that has evolved but can’t be used to distinguish groups of organisms (i.e. having eyes can’t be used to distinguish monkeys from dogs)