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
Why don’t frugivores often have specialized traits?
Fruits are easy to spot, full of easy-to-digest sugars that make them taste good—and, often, easy to chew and digest not being too fibrous or tough).
What physical characteristics do frugivores have that enable them to live on this diet?
bunodont molars, large incisors for slicing through the outer coatings on fruit. Stomachs, colons, and small intestines that are intermediate in terms of size
What physical characteristics do insectivores have?
small molars with pointed cusps that allow them to puncture the exoskeleton of the insects. Once the outer shells of the insects are punctured, insects are not difficult to digest, so insectivores have simple stomachs and colons and a long small intestine.
Nutritionally, insects provide a lot of protein and fat but are not plentiful enough in the environment to support large-bodied animals, so insectivores are usually the smallest of the primates.
Why do primates that eat primarily leaves (foliovores) need many adaptations?
Plants do not want animals to eat their leaves. Leaves are the way plants get their energy from the sun, therefore, plants evolved to make their leaves very difficult for animals to eat. Leaves often have toxins in them, taste bitter, are very fibrous and difficult to chew, and are made of large cellulose molecules that are difficult to break down into usable sugars. Hence many adaptions are needed to consume leaves
Shearing crests
Sharpened ridges that connect cusps on a bilophodont molar
Foliovores have what specific adaptations?
Shearing crests, specialized digestive systems (large, long intestines and special gut bacteria that can break up cellulose), and the largest of all primates.
Activity Patterns
Whether an organism is active during the day or nighttime
Diurnal
Organisms that are active during the day.
Nocturnal
Organisms that are active during the night.
Cathemeral
Organisms that are active through the 24-hour period
What types of social groups exist among primates?
solitary, others live in pairs, and still, others live in groups of varying sizes and compositions.
Where do scientists see differences in primate behaviors?
In activity patterns, social grouping, and habitat use
Locomotion
How primates move around
Vertical clinging and leaping
an animal grasps a vertical branch with its body upright, pushes off with long hind legs and then lands on another vertical support branch. Animals who move in this way usually have longer legs than arms, long fingers and toes, and smaller bodies. Vertical clinger leapers also tend to have elongated ankle bones, which serve as a lever to help them push off with their legs and leap to another branch.
Quadrupedalism
The most common form of locomotion. Walking on all fours. Arboreal quadrupeds usually have shorter arms and legs and longer tails, while terrestrial quadrupeds have longer arms and legs and, often, shorter tails.
These differences relate to the lower center of gravity needed by arboreal quadrupeds for balance in trees and the longer tail required for better balance when moving along the tops of branches. Terrestrial quadrupeds have longer limbs to help them cover more distances more efficiently.
Brachiation
Swinging below branches by the hands. To be an efficient brachiator, a primate needs to have longer arms than legs, flexible shoulders and wrists, a short lower back, and no tail
Semi-brachiation
They can swing below branches like brachiators; however, their arms and legs are about the same length, useful because they are quadrupedal when on the ground. They still have flexible shoulders. They also use long prehensile tails as a third limb when swinging.
Prehensile tails
tail of an animal
Bipedalism
walking on two feet
What superfamily do humans belong to? And which species are our closest relatives?
Hominoidea. Chimpanzees and bonobos.
Clade
a group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics.
How do scientists determine which species belong in a particular clade?
They’re determined by derived traits shared by groups of taxa as well as genetic similarities.
African clade
A clade that includes humans, chimpanzees, bonobos, and gorillas which means they all share a common ancestor.
Asian clade
Orangutans are members of the Asian clade.
Grades
It doesn’t explain if certain species share a common ancestor. Instead, it reflects the levels of adaptation and overall similarity.
What’s the difference between grade vs clade grouping?
Grade grouping is determined based on similar appearance and lifestyle. Clade grouping is based on genetic similarities.
Why do anthropologists prefer to use Clade classifications as opposed to grade?
Because we want to organize species by their evolutionary relationships rather than their physical appearance.
Which two suborders exist in the Order Primates?
Suborder Strepsirrhini and Suborder Haplorrhini
When did the two suborders split off?
70-80 million years ago
What groups are in the strepsirrhines?
Lemurs, lorises, and galagos
How do strepsirrhines differ from haplorrhines?
Haplorrhines have retained primitive traits from the last common ancestor of primates. Streps have two derived traits after they split off from happlorrhines
Grooming Claw
it’s on the second digit of each foot
Tooth/dental comb
there are six teeth in the toothcomb—the four incisors and the two canines
What traits do strepsirrhines have?
- Longer snouts (better sense of smell)
- Wet noses
- Scent marking
- mobile ears
- worse visual senses
- eyes that reflect light which enhances the ability to see in low light conditions
- Solitary behavior
- noturnal
- arborreal
- diet of insects and fruit
- small in size
- great at leaping
- grooming claw (derived)
- dental comb (derived)
Rhinariums
wet noses
Scent marking
rubbing scent glands or urine on objects in the environment to communicate with others
Tapetum lucidum
a reflective layer at the back of the eye that reflects light and thereby enhances the ability to see in low-light conditions
Where are strepsirrhines found?
in Asia, Africa, and on the island of
Madagascar
Mouse lemurs
smallest of all primates
Indris
largest of the lemurs
aye-aye
most unique of the lemurs. Rodent-like front teeth that grow continuously and a long-bony middle finger that it uses to fish grubs out of wood. It has a very large brain compared to other strepsirrhines, which it fuels with a diet that includes bird’s eggs and other animal matter.
Fork-marked lemur
metabolize the cyanide in bamboo
What are significant differences in the environments of lorises, pottos and galagos compared to lemurs?
They share their environment with apes. South and Southeast Asia Central Africa
South and Southeast Asia Central Africa
Fovea
a depression in the retina at the back of the eye containing concentrations of cells that allow us to see things very close up in great detail
Monomorphic
males and females are the same size
Rhinarium
Rhinarium is the part of the nose that has a naked surface, meaning it has no fur but glabrous skin
What groups can haplorrhine be divided into?
Tarsiiformes, which includes the tarsiers of Asia; Platyrrhini, which includes the New World monkeys of Central and South America; and Catarrhini, a group that includes the Old World monkeys and apes of Asia and Africa, as well as humans
faunivorous
diet of animal matter
Why do some people think tarsiers don’t belong in the haplorrhine group?
Because they have traits like strepsirrhines as well
Why have they been left in the haplorrhine group?
Because they have more genetic material more in common than with the strepsirrhines
playtrrhini primates characteristics
“Platy” means flat and “rhini” refers to noses and, indeed, New World monkeys have noses that are flat and wide, with nostrils that are far apart, facing outward, and usually round in shape
smaller and less sexually dimorphic than catarrhines
Aborreal
Less vision
Polymorphic color vision
perceive many colors
monochromatic
they cannot distinguish any colors
What are some special characteristics of the catarrhine?
distinctive nose shape, with teardrop-shaped nostrils that are close together and point downward
On average, catarrhines are the largest and most sexually dimorphic group of primate
trichromatic
Catarrhini divided into
Superfamily Cercopithecoidea
Superfamily Hominoidea
bilophodont molars
“bi” meaning two, “loph” referring to ridge, and “dont” meaning tooth
ischial callosities
the part of your pelvis that you are sitting on right now
These function as seat pads for cercopithecoids, who often sit above branches when feeding and resting
natal coats
infants whose fur is a completely different color from their parents
Ethnoprimatology
which involves studying the political, economic, symbolic, and practical relationships
between humans and non-human primates
In many of these regions today, the relationships between humans and non-human primates are complicated. The bushmeat and pet trades make these animals valuable at the expense of many animals’ lives, and in some areas, non-human primates have become pests who raid crop fields and consume valuable foods
What advantage do Old World monkey’s teeth give them?
four cusps arranged in a square pattern and have two ridges connecting them. It is thought that this molar enabled Old World monkeys to eat a wide range of foods, thus allowing them to live in habitats that apes cannot.
Why have Cercopithecoidea been able to become more diverse and numerous than hominoids?
this monkey group has increased in numbers and diversity. In part, their success over hominoids is due to the faster reproductive rates of cercopithecoids relative to hominoids
1-2 years
Cercopithecoidea what two groups?
two groups, the leaf monkeys and the cheek-pouch monkeys
leaf monkeys
majority of leaf monkey species live in Asia
folivores
babies with natal coats
odd noses
cheek-pouch monkeys
rugivorous or omnivorous
Asia and Africa
pack food into their cheek pouches
Y-5 molars
five cusps separated by a “Y”-shaped groove pattern
olecranon process
improved extension in our arms
styloid process
very flexible wrists
Where can gibbons and siamangs be found?
Southeast Asian tropical forests
Sagittal crests
believed to function as both additional attachment area for chewing muscles but also in sexual competition
male bimaturism
Male orangutans are known to delay maturation until one of the more dominant, flanged males disappears
Where do orangutans live and what is their primary diet?
These large red apes are found on the islands of Borneo and Sumatra in Southeast Asia. highly frugivorous but will supplement their diet with leaves and even bark when fruit is less available
Knuckle-walking
the fingers are curled under and the weight is carried on the knuckles
Where do Gorillas live and what do they eat?
Central Africa
folivorous, although they can be more frugivorous depending on fruit seasonality
Pan trolodytes
the common chimpanzee
Pan paniscus
the bonobo
Genus Pan
two species: Pan troglodytes the common chimpanzee) and Pan paniscus the bonobo).
Why are bonobos and chimpanzees separated?
Seperated by the Congo River
If you were at a zoo, how could you tell the difference between a bonobo and a chimpanzee?
Bonobos are smaller. Their hair parted down the middle of their foreheads, and are born with dark faces
Homology
looking at traits that are shared between two taxa because they inherited the trait from a common ancestor
analogy
When two or more taxa exhibit similar traits that have evolved independently, the similar traits evolve due to similar selective pressures. Also sometimes called convergent evolution, parallel evolution, or homoplasy.)
