˗ˏˋ primates ´ˎ˗ Flashcards
what class are primates in?
- class mammalia
- having fur or hair
- producing milk from mammary glands
- being warm-blooded
how old is the primate order?
about 90 million years old.
what is homology?
a similar trait found in different species because it was inherited from a common ancestor.
what is analogy?
a similar trait found in different species that arose independently.
what is a clade?
- a grouping based on ancestral relationships; a branch of the evolutionary tree
- the african clade grouping of humans, gorillas, chimpanzees, and bonobos
what is the asian clade?
a grouping that includes orangutans and their extinct relatives.
what are grades?
- a grouping based on overall similarity in lifestyle, appearance, and behavior.
- placing orangutans, gorillas, bonobos, and chimpanzees into a group, and excluding humans.
what are ancestral traits?
a trait that has been inherited from a distant ancestor.
what are derived traits?
a trait that has been recently modified, most helpful when assigning taxonomic classification.
what are generalized traits?
- a trait that is useful for a wide range of tasks
- opposable thumbs
what are specialized traits?
- a trait that has been modified for a specific purpose
- horse hooves for running
what are primate traits?
- reliance on vision (many primates can see in trichromatic color, meaning reds, blues, yellows, and greens)
- postorbital bar (a bony ring that surrounds the eye socket, open at the back)
- large brains
- extended life histories
- arboreal
- tactile pads
- short snouts
- live in tropics
- pentadactyly
what are evolutionary trade-offs?
when an organism, which is limited in the time and energy it can put into aspects of its biology and behavior, is shaped by natural selection to invest in one adaptation at the expense of another.
what does it mean to be arboreal?
a descriptor for an organism that spends most of its time in trees.
what does it mean to be pentadactyly?
having five digits or fingers and toes.
what are tactile pads?
- sensitive skin at the fingertips for sense of touch
- animals with a prehensile tail have a tactile pad on the underside of the tail as well
what does it mean to be heterodont?
having different types of teeth.
what does it mean to be homodont?
having only one type of tooth.
what does it mean to be sexually dimorphic?
when a species exhibits sex differences in morphology, behavior, hormones, and/or coloration.
what is a diastema?
a space between the teeth, usually for large canines to fit when the mouth is closed.
what is a dental formula?
- the number of each type of tooth in one quadrant of the mouth, written as number of incisors: canines: premolars: molars
- 2:1:3:3 (new world monkeys)
- 2:1:2:3 (old world monkeys, apes, humans)
what are frugivores?
- having a diet of mainly fruit
- broad molars, rounded cusps
- intermediate digestive systems
what are insectivores?
- having a diet of mainly insects
- small molars, pointed cusps
- simple stomachs
what are folivores
- having a diet of mainly leaves
- broad molars, sharp cusps
- specialized digestive systems