Lab 6: Primate Classification Flashcards
Taxonomic classification
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).
shared derived traits
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.
Taxonomy: Domains and Kingdoms
broadest, most encompassing taxonomic levels used to group organisms sharing general features in common
There are 3 domains and 6 kingdoms
Taxonomy: Phyla
less broad classification than domain or kingdom
Subcategories of domains and kingdoms
Plural is phyla
Taxonomy: Classes
Subgroups of phyla
Taxonomy: Orders
Subgroups of classes organized into families
Taxonomy: Genus
A subgroup of families
Plural is genera
Taxonomy: Species
Subgroup of Genus
The biological species concept
The idea that members of a species are recognized as a reproductively isolated group of organisms
Reproductive isolation
refers to geographic, behavioral, morphological, and/or genetic differences between species that prevent them from commonly producing fertile, viable offspring in the wild.
Primate Classification: Gradistic classification
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.
Primate Classification: Cladistic classification
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
Strepsirhines
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.
Lemurs
Part of Strepsirhines suborder
diverse taxonomic group, accounting for at least 13% of all primate species in the world.
Haplorhines
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.
Tarsiiformes
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).
Platyrrhines
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.
Catarrhines
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.
Cercopithecoidea
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.
Hominoidea.
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.
Primitive Traits
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)
