Chapter 5 Flashcards
Linnaean classification
the system we use for organizing life-forms
Why do we study non-human primates?
Because humans are primates, we share a wide range of behavioral and morphological traits with the other species who also fall into this group.
How many different types of mammals exist?
three: monotremes, marsupials, and placental mammals
Monotremes
A type of mammal. Most primitive of the three mammals, which means they’ve retained more ancient traits in comparison to other mammals. Monotremes, which include echidnas and duck-billed platypuses, lay eggs rather than give birth to live young.
Marsupials
Mammals that gestate for a very short period of time and give birth to relatively undeveloped young. Kangaroos and koalas.
How many orders are in the class mammalia?
20
Placental mammals
internally gestate for a longer period of time and give birth to fairly well-developed young who are then nursed. These include primates.
What primates are
Which mammalian order is the oldest?
Primates-91 million years old.
What characteristics do all mammals have in common?
having fur or hair, producing milk from mammary glands, and being warm-blooded
The order Primate contains what species?
lemurs and lorises, tarsiers, monkeys of the New and Old Worlds, apes, and humans, all of which are united in sharing a suite of anatomical, behavioral, and life history characteristics
How are traits used in evaluating species?
They are used in evaluating the relationship between species to see how they’re related to each other
Primitive Trait
A trait that a taxon (unit of animals) have inherited from a distant ancestor
Derived Trait
Traits that have been more recently altered
Genus Pan
Includes two species called the chimpanzee and the bonobo. Humans split from this group because of the derived adaption of walking upright.
Generalized Traits
Characteristics that are useful for a wide range of things
How do taxons work?
As taxons split off, the newer ones have more derived traits in comparison to the older ones which have more primitive traits from their ancestors.
Opposable Thumbs
Having thumbs that go in a different direction from the rest of the fingers, allows for grasping with hands and feet. Appeared 55 million years ago.
Specialized traits
Traits that have been modified for a specific purpose.
What does it mean that primitive and derived traits and derived traits are relative terms?
This means that depending on what taxa are being compared, a trait can be either one
Postorbital bar
A bony ring around the outside of the eye that protects the eye
Trichromatic vision
the ability to distinguish reds and yellows in addition to blues and greens
Red, green, and blue
Why might trichromatic vision have re-evolved?
Detecting food, leaves, predators, fruits, mate theory, etc. There is no one specific theory/reason why.
Evolutionary trade-offs
Energy spent on one trait means cutting back on energy spent on another. Ex: better vision=worse sense of smell. Better vision asks for more energy so worse smell is used to compensate for the larger amount of energy expounded.
Arboreal
Organisms that spend their time in trees