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
Pentadactyly
five digits/fingers on each limb
Terrestrial
Organism that lives on the ground
Tactile pads
allow organisms to have a fine sense of touch. Primates use this fine sense of touch for handling food and, in many species, grooming themselves and others.
How do nails help primates?
Helps us better manipulate objects instead of claws and hooves.
What do primates use grooming for?
Social bonds
Postorbital Plate/closure
protects the back of the eye socket. Primates that have more converging eyes have this feature.
Dichromatic vision
Most mammals (some primates) only see in blue and green. Some mammals have such vision which allows them to have better night vision.
What traits do all primates have in common?
Strong and convergent (overlapping) trichromatic vision. Size and complexity of our brains which includes better functions. Reduced snouts. Differs in hands and feet. Mostly living in trees. Long life spans. Strong social networks that don’t migrate and interactions with the same individuals. Live in the tropics.
Life history
The pace which an organism grows, reproduces, ages, and so forth.
What is the life history of primates?
They grow and develop more slowly, have fewer offspring per pregnancy, reproduce less often, and live longer. Also, they invest more in their offspring.
How does a primate’s brain structure differ from the brain structure of other animals? What theories might explain the size of the neocortex?
Primates have larger visual centers and different wiring in comparison to other mammals.The neocortex, which is used for higher functions like consciousness and language in humans, as well as sensory perception and spatial awareness, is also larger in primates relative to other animals. The brain has more folds increasing surface area. Helps primates with the process of finding fruits
What do scientists use to place primates into taxonomic groups?
dental characteristics, locomotor adaptations, and behavioral adaptations.
What can we learn from teeth and jaws?
teeth of any species have evolved to reflect what that organism eats and so tell us directly about their diet. Second, variation in tooth size, shape, and number tells us a lot about an organism’s evolutionary history. Furthermore, differences in teeth between males and females can tell us about competition over mates. Lastly, teeth preserve really well in the fossil record. Enamel is hard, and there is little meat on jaws so carnivores and scavengers often leave them behind. Because of this, very often we find a lot of fossil jaws and teeth, and so we need to be able to learn as much as we can from those pieces.
Homodont
One type of tooth
Heterodont
multiple types of teeth
that mammals use in different ways
Incisors
slicing
Premolars/molars
grinding food
Canines
most primates not humans) use as weapons against predators and each other.
Sexually
dimorphic
When a species exhibits sex differences in morphology, behavior, hormones, and/or coloration
Hone
sharpen the the sides of their canines by gnashing the teeth together
Diastema
Space between the teeth. As canines get larger, they require a space to fit in order for the jaws to close.
Dental formula
the number of each type of tooth an organism has. The dental formula tells you how many incisors, canines, premolars, and molars are in each quadrant of the mouth
Cusps
little bumps which in some species can be quite sharp) that you can feel with your tongue on the surface of your back teeth
What can teeth tell us about diet?
Primates are known to eat a wide range of plant parts, insects, gums, and, rarely, meat. While all primates eat a variety of foods, what differs among primates are the proportions of each of these food items in the diet.
Frugivores
organisms who have a fruit diet
Insectivores
organisms who have an insect diet
Folivores
organisms who have a leaf diet
Gummivores
organisms who have a gum and sap diet
Bunodont molars
broad chewing surface with low, rounded cusps