Chapter 6 Flashcards
mammals are divided into 3 groups:
- Metatheria (aka marsupials)— that reproduce without a placenta, including the marsupials
e.g. kangaroos give birth to an embryonic offspring that goes into the pouch, latches onto nipple and further develops - Prototheria— that reproduce by egg-laying, then the nurse young from nipples. The Australian platypus and echidna are the only living monotremes
Eutheria— that reproduce with the placenta and uterus
What exactly is a primate?
primates are mammals with grasping hand, large brains, a high degree of learned rather than innate behaviour and a suite of other traits
the order primates are dived into 2:
strepsirhine (strepsirhini)—
haplorhine (haplorhini)—
what are strepsirhine (strepsirhini
suborder of the order primate that includes the prosimians, excluding the tarsier
what are haplorhine (haplorhini)
suborder of the border primate that includes the answer anthropoids and the tarsier
Some Taxonomists use a more traditional naming system, which is based on aspects of anatomy, for the major primate groups:
prosimian and anthropoid suborders
what are prosimian—
of the primate suborder Prosimi that includes the lemurs, lorises, galagos and tarsiers
what are anthropoid—
of the primate suborder anthropoid that includes the Monkeys, apes and hominids
Distinguish primates from other mammals by a set of traits that they all share:
GENERALIZED BODY PLAN
GRASPING HANDS WITH OPPOSABLE THUMBS OR BIG TOES
FLATTENED NAILS
FORWARD FACING EYES WITH STEREOSCOPIC VISION
GENERALIZED TEETH
PETROSAL BULLA
ENCLOSED BONY EYE ORBITS IN THE SKULL
describe GENERALIZED BODY PLAN
primates body plan is generalize, not specialized like a giraffes neck is (for example)
their body type gives them much versatility… able to have many modes of travel (running and walking), swinging leaping, etc
all non human primates are quadrupeds (walk on all 4s… their hinds are longer than front legs to help with support when leaping and sitting, they can actually run and walk as well as swing from trees!)
describe GRASPING HANDS WITH OPPOSABLE THUMBS OR BIG TOES
this is believed to be a fundamental primate adaptation
although some strepsirhine don’t fully exhibit this trait
Nonhuman primates have an opposable hallux (big toe)
humans do not have this but have developed a foot that makes bipedal striding easier
describe FLATTENED NAILS
instead of claws
this the case for all primaries except one group, the marmosets and tamarins
describe
FORWARD FACING EYES WITH STEREOSCOPIC VISION
gives excellent depth perception because the overlapping field of vision provide a three dimensional view of the world… even though we loose 360 vision it is still beneficial
the arboreal hypothesis; for the origin of private adaptation that focuses on the value of grasping hands and stereoscopic vision for life in the trees— by Frederick Wood-Jones and George Elliott Smith in the 1920s
1970’s Matthew Cartmill argued that squirrels also did this but were more adapt with greater agility when it came to working the trees… he argued that we should consider how the very earliest pirates and their close kin lived in order to understand primate origins
he came up with the visual predation hypothesis
what is the visual predation hypothesis
— hypothesis for the origin of primate adaptation that focuses on the value of grasping hands and stereoscopic vision for catching small prey
describe GENERALIZED TEETH
shape tells us a lot about diet
most nonhuman primates eat leaves, fruit and occasional animal protein (insects)… only the tarsier eats mainly animal protein
nonhuman primates do not have specialized teeth (for either meat or greens)
dental arcade— the parabolic arch that forms the upper or lower row of teeth
there are 4 types of teeth arranged in the following order; 2 incisors, one canine, two premolars
exception to this is the New World Monkeys who have a third premolar and the strepsirhines who have varying dental formulas
describe PETROSAL BULLA
the tiny bit of skeleton that protects the inner ear
single bony trait that all primates share
occurs in no other mammalian group
describe ENCLOSED BONY EYE ORBITS IN THE SKULL
could protect the primate more efficiently than other lower mammals
this is more complete in haplorhines than jstrepsirhins who tend to have just a bony ring around the orbit
Life History Traits of primates:
SINGLE OFFSPRING
LARGE BRAINS
EXTENDED ONTOGNY
describe SINGLE OFFSPRING
nearly all primates give birth to at least one, many mammals (especially smaller ones) have litters ortwins
marmosets and tamarins are the exception that give birth to twins
prouder fewer offspring so they can invest much time and energy in keeping the current one(s) healthy and alive
describe LARGE BRAINS
primates have high degree of encephalization, or evolved increase int he volume of the neocortex— the part of the brain that controls higher cognitive function; the cerebrum
more obvious int he brain of haplorhine than strepsirhines
we can tell it is bigger due to the increased # of convolutions (ridges on the surface of the brain)
reason for the expansion of the brain is debated because it is so large that is metabolically expensive to grow
describe EXTENDED ONTOGNY
primates live by learned behaviours as much as they do by hardwired instinct
they are socialized so the offspring can learn
ontogeny— gorilla may live 20x longer than a mouse, but it takes 15 years to sexually mature where a mouse only takes 2 weeks (80x longer)
it takes much longer for primates o learn all the skills they need (to live and socialize) where the mouses (for example) only need to learn to find food and water!
wha is ontogeny
the life cycle of an organism from conception to death
primates are notable for the extended length of each stage
are primates active during the day or the night
primate species that are active during the day have colour vision whereas species that are active during night rely on smell
define nocturnal—
active at night
define diurnal—
active during daylight hours
fact: most strepsorhines are nocturnal and all except one haplorhines are dinural
most strepsorhines are nocturnal and all except one haplorhines are dinural
what is sociality—
group living, a fundamental trait of haplorhine primates
helps primates access mates and fend off predators
of the haplorhine primates, only the orangutang is not in social groups
are monkeys more evolved than lemurs
and do not think that monkeys are more evolved than lemurs (for example), natural selection just favoured some sociality traits in monkeys than other species
are there set ways to classify primates
not all taxonomists agree on how to classify primates, and one nonhuman primate, the tarsier, straddles the 2 suborders
what are The Strepsirhines
include the lemurs of Madagascar, and the lorises and galas of mainland Africa and tropical Asia
strepsirhines and prosimians are not completely synonymous; one prosimian primate, the tarsiers is a haplorhine not a strepsirhine
all strepsirhines share the same anatomical features and lack of complex sociality
what are The Haplorhines
includes the tarsier, the new world monkeys, old world monkeys, apes and hominins
guided more by vision than olfaction
living ones have a lower jaw that is fused at the midline in adulthood; in prosimians and most other animals, the jaw is 2 pieces joined by cartilage
with a few exceptions, most are diurnal and live in social groups
what are THE TARSIERS
haplorhine primes that are thought to occupy an evolutionary position between the prosmian and anthropoid primates
have a mixture of the categories traits
generally considered to be closer to haplorhine
have an owl-like ecological role (nocturnal, same diet) live monogamous
what are The New World Monkeys classified as
classified as playtyrrhini— infraorder of the order. Primates that is synonymous with the New World monkeys or ceboids
wha are the The New World Monkeys
in superfamily Ceboidea
refers to the flat shape of the nose
all share 3 features;
small body size
3 premolar teeth
arboreality— some even have prehensile tail— grasping tail possessed by some species of the primate families Cebidae and Atelidae
Ceboidea are classified as 5 families;
cebidae, pithecidae, atelidae, aotidae, callitrichdae
callitrichdae— unique for treat that resemble those of lower mammals
some species polyandrous occurs— mating system in which one female mates with multiple males
what are Old World Monkeys
infraorder catarrhini— infraorder of the order Primates that includes the Old World monkeys, apes and hominins
as a family, they share ischial callosities— thickened calluses on the rump that presumably make sitting on rough surfaces more comfortable
also have double ridged molar teeth (aka bilophodont molars) thought to be evolved to eat leaves
wide range of sizes
2 subfamilies of the Cercopithecidae merit special attention; the Colobines (aka leaf monkeys and others like them) and the colobus of Africa— they have evolved a semichambered stomach that resembles that of a cow and can digest tough, cellulose-laden foods in an organ called the foergut
this helps them find food in dense forests that they wouldn’t have been able to eat otherwise, yet these subfamilies have the highest nicer of infanticides
they have a cheek pouch to store food
Some old world monkeys have estrus— hormonally influenced period of sexual receptivity in some female mammals with corresponds to the timing of ovulation
during this, the skin around her genitals flats and acts as a billboard of her fertility
what is superfamily; hominin (Homininae)—
member of our own human family past or present
what does hominin (Homininae) include
member of the gibbon, or lesser ape, family
what is the subfamily of hominins
pongid (Pongidae)— 1/4 great ape species: gorilla, chimpanzee, bonobo or organutan
what is brachiation—
mode of arm-hanging and arm-swinging that uses a rotating shoulder to suspend the body of an ape or homonin between a branch or to travel between branches
this arm provides basically the fame function as the prehensile tail
only in great apes do we see technologies that resemble simple versions of human tool
true or false despite their social behaviour, primates parts of ecosystems
true
what is ecology—
the study of the interrelationships of plants, animals and the physical environment in which they live
how does the environment influence natural selection
the environment provides a template in which natural selection molds behaviour
at the same time, primates influence the ecology in the sense that they spread seeds
what kind diet do most primates have
most primates are herbivores
exception to this are many lower primates and a few higher primates (including humans)
one primate group is entirely carnivouris— the tarsier of SE Asia
Trees don’t want the animals to eat all their leave (they would die!), so they do what
Trees don’t want the animals to eat all their leave (they would die!), so they produce fruit which they actually want to be eaten so the seeds can be spread!
what are folivores—
animals that eat a diest composed mainly of leaes, or foliage
trees and these do not get a long, as the trees are at constant risk of dying
trees and fruit eaters get along really nicely
what is phenology—
the leafing and fruiting cycles of a forest
many trees have asynchronous cycles what is this
when one tree is fruit ridden, the other has non to ensure that the whole stand of trees is not cleared at once
many primates have developed specialized diets that allow for what reaosn
for them to coexist with other species
what are secondary compounds—
toxic chemical compounds found in the leaves of many plants which the plants use as a defence against leaf-eating animal
specialize gut can digest this! only some animals have it
this allows the cohabitation of monkeys that can do this and monkey that cant
what is activity budget—
the pater of walking, eating, moving, socializing and sleeping the all nonhuman primates engage in each day
allows the primate to compensate for the calories expended with calories exhumed
linked to dietary quality; those that live on low calorie diets are not as productive and active as those that live on high calorie diets
problem with primates is that it competes for food with many other mammals (the high calorie diet)
which is more important; intragroup feeding competition or intergroup feeding competition
scientists have debated over which is the more important influence on the evolution of primate social systems; competition between members of the groups (intragroup feeding competition) or competition between groups (intergroup feeding competition)
what is intragroup feeding competition
occurs when the group wants to eat from the same tree (fir example) and get the ripest fruit, the older and stronger males would get it first and that would cause conflict because the weaker ones would get it last or not at all (contest feeding competition)
this causes more problems because the weaker ones wont be able to get enough food and they will stay weaker and have lower fertility and it is a cycle they can’t escape
what is competition between groups
(intergroup feeding competition)
what is scramble feeding competition—
when everyone gets food in the end (if leaves are all over the ground)
there is much less competition here and most members of the group end up eating well… there is not an apparent/strict hierarchy here
what is home range—
the spatial area used by a primate group
all primates live in one, can be smaller than a football field or more than a few km long,
this range must contain all the things they need to survive (water shelter etc)
they often overlap slightly or completely
what is core area—
the part of a home range that is most intensively used
whats territory—
the part of a home range that is defended against other members of the same species
this defence can be in the form of vocalizing intimidation, chasing, physical violence or even lethal means
why be territorial?
defend food sources that are highly nutritional, because females are on these territories
lack of field observation, but can make a few generalizations about predation:
small bodies nonhuman primates are more vulnerable than larger species
many nonhuman primates exhibit behaviours that appear to have evolved in response to a threat of predation; alarm calls, for example
the pattern of predation on the colobus depend very much on where the colobus lived relative to the border of the territory of the chimpanzee community;
if there were individuals near their core, they would be much more aggressive and likely to kill than if they were on the edges of home range
if primates live so close together, why isn’t there more competition for food?
there is and was;
ecological theory predicts that when there are 2+ organisms with very similar food preferences, sharing the same space, they will diverge from one another in some critical aspect of their niche or ecological role
e.g. 2 monkeys that eat the same thing will be found to eat different things when food is scarce; you can find one series up in the trees and the other species on the ground
niche separation occurs among all primates that are sympatric, and such divergency often is evident only during ecological crunch times
although diets may overlap, actual contest for food is rare
some primates form polyspecific groups, what are these
made up of 2+ species that travel and feed together for part or all of each day
