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Evolution
The first life- About 10-20 billion years ago, universe was born
4.5 billion years ago was the earth born
3.5 billion years ago, first form of life- CYANOBACTERIA- was formed.
Why is CYANBACTERIA life?
1) They had a metabolism
2) They were able to reproduce
Moving Organisms
700 million years ago-organisms actually locomoted by themselves. Based on the fact that we have fossil evidence of burrows in the
seafloor.
Chordata-first significant animal fauna. Occurred during the Cambrian period of the Paleozoic
era
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they lacked rigid cell wall, they had the ability to eat particulate matter.
they move around actively- can be classify them in the sub-kingdom of METAZOA(animals that can locomotive) rather than
PROTOZOA(animals that do no move themselves)
classified as CHORDATA because they have dorsal nerve cord(never cord through their back)
The Vertebrates- 400million years ago
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vertebrates have backbone, a cranium, a brain, olfactory organ(smell), true eyes, a skin made up of dermis and epidermis,
internal organs, and reproductive system.
Amphibians- 340 million years ago
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animals on Earth first started move onto land.
Reptiles- 340-280million years ago
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to cut off completely from water, things that made it possible :1) amniotic egg (egg that does not need water to survive)
225-65 million years ago- went through a tremendous adaptive radiation and dominated terrestrial life
called the AGE OF REPTIES
Mammals- 65 million years ago through present
took over after the extinction of the dinosaurs
CHARACTERISTICS OF MAMMAL1)
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they posses hair
they are warm-blooded(homeothermic)
they possess mammary glands
they are heterodonts- individual mammal has different shapes and sizes of teeth. (unlike crocodile’s teeth which are mostly the
same, we have I-C-P-M
5) They possess relatively large brains
Why is teeth important
1) they are harder than bone and is more likely to fossilize
2) tell a lot about food and lifestyle and thus anatomy of organism
Three Subclasses of MAMMALS
1) Prototheria- or monotremes they lay eggs instead of giving birth
 uncommon today, survive only in form of platypus and spiny anteater
2) Metatheria- or marsupials give life birth prematurely (newborns not capable of outside world
 usually clamber into some kind of pouch on the mother
3) Eutheria- placentals
 has placenta to allow fetus to develop longer
Primate Characteristics
A) Climbing Adaptations (Arboreal lifestyle)-living in the trees
1) Retention of clavicle.
2) Retention of five digits on hands and feet.
3) Prehensile hands and feet (primates can grasp with their hands and feet)
4) Nails instead of claws
5) A tendency towards erect posture
B) Vision characteristics1)Binocular stereoscopic vision. -smaller total field of vision but better judgment of distance
2) Increased reliance on vision and a decreased reliance on smell.-demonstrated by post-orbital bar behind the eye.
C) Other characteristics
1) larger brain sizes
2) longer gestation, infancy, and juvenile periods of their life- less time as adults
3) a tendency toward sociality.
The Origin of Primates1)70 million years ago- great adaptive radiation of mammals. What made this possible?
a) first angiosperms(flowering plants) evolved. Angiosperms are a great food source to animals
b) Earth entered a warming period expanding the forest area
c) Large meteorite in Yucatan Peninsula of Mexico killing plants around the world- gave rise to smaller animals
Definitions1) adaptive niche- They whole way of life of an organism (where it lives, diet, mating habit, etc)
2) morphology-the physical structure of an organism( size and shape)
3) Substrate- The surface on which an animal moves or rest( rocks, ground, trees)
Primate Locomotion
A) Arboreal Quadrupeds- walking on all fours in trees
1) have arms and legs which are approximately same length.
2) hind limbs provide most propulsion while front limb steers
3) morphology is marked by shorter limbs than terrestrial quadrupeds to help them keep balance
4) have long tails to maintain balance
5) long grasping fingers and toes to help grip branches
6) long olecranon process( part of elbow structure) to hlep maintain strong grip while arms are flexed
B) Terrestrial Quadrupeds
1) main concerns is not balance but escaping predators
2) longer limbs and shorter digits
3) more restricted shoulder joins
C) Suspensory Locomotion
1) True brachiation-swinging underneath the substrate, from branch to branch, using one’s arm
a) exhibited by lesser apes- gibbons and siamangs
b) their scapula is moved towards the back of their body
c) very mobile hip joint, no tail, and very board thorax(upper torso)
d) short legs and long arms- for more reach
e) long curved fingers- for more grip
2) Semi brachation- new world monkeys,
a) swings but is supplemented with leaping and quadrupedalism
b) prehensile tail- used as a fifth limb to grasp branches
c) morphology between brachiators and quadrupeds
3) Suspensory climbing-exhibited only by orangutans
a)
since they are large- to avoid breaking branches, they hold onto several different branches with different limbs when
moving
D) Leaping
1) developed style of prosimians (lemurs and tarsiers)
2) found in the understory of rainforest where their are mainly vertical substrates
3) long lumbar region to allow them to snap their backs to gain more momentum
4) very long legs and really long digits
E) Bipedalism
1) only humans use bipedalism as main means of locomotion
2) problem is balance and side-to-side motion
3) a)long hindlimbs, b)short toes,c) femur with a large head, d)board flat pelvic structure, e)curved spine, f) adducted knee(
structure which allows the upper part of the legs to be angled to prevent excess side-to-side movement when walking
Prosimian characteristics
1) exhibit a great reliance on olfaction
a)have rhinaruim(wet nose) -except tarsiers
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b)Longer snouts
c)more scent glands (marking territory for mating)
incomplete post-orbital closure
a) eyes do not face far forward
have unfused mandibular symphysis- jaw composed of 2 bones fused together.
have single claw located on second digit of foot( grooming claw)
incisors and canines project outward and flatten (tooth comb)
except for lemurs,most prosimians are nocturnal
smaller brain size to body size
have more than one set of teats indicating multiple births
Lorises infra-order
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have small bodies
nocturnal
insectivorous
all arboreal
solitary
slow arboreal quadrupeds (galagos are leapers
have single births while galagos give birth to twins and triplets
Lorises found in Southeast Asia and Africa, galagos (bush babies) are found only in Africa
Lemurs
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infra-order
found only in Madagascar
since not having to compete with monkeys, they have wide variability of adaptations
some nocturnal, some diurnal
some are arboreal, some are terrestrial, etc, etc
Tarsiers infra-order
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found only in Southeast Asia
have a 2-1-3-3/1-1-3-3 dental formula
small body, insectivorous, arboreal creatures
variable social structures
best leapers around
have mostly prosmian-like characteristics but lacks a rhinarium and possess complete post-orbital closure
molecular data recently show tarsier more closely related to anthropoids.
Anthropoids characteristics
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they lack a rhinaruim
they have a shortened snout
they have full post-orbital closure
their eyes are forward facing
they lack the dental comb possessed by some prosimians
they have completely fused mandibles
they have no grooming claws
they are usually larger than prosimians
they are diurnal
they possess larger brain relative to body
Old World monkey characteristics (CATARRHINES)
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old world monkeys inhabits Africa, Asia and southern Spain
2-1-2-3 dental formula
have narrow nostrils that face downward
narrow nasal septum
have ischial callosities- allows sitting for hours without butt or legs going to sleep
bilophodont molars (two ridged tooth) - 4 cusps, 2 ridges
some are arboreal, some are terrestrial
Cercopithecoidea- subdivision of the catarrhini
Cercopithecinae superfamily vs Colobinae superfamily
1) Cercopithecines eat both plants and animals while Colobines are folivores (only leaves)
2) Cercopithecines lack specialized stomach to break down leaves while Colobines have different GI tract to help break down leaves
3) Cercopithecines have cheek pouches to stuff food
4) Cercopithecines are an African group while Colobines are spread across Africa and Asia
5) Cercopithecines are both terrestrial and arboreal, Colobines are mainly arboreal
Colobines’ special stomach-(sacculated stomachs)
1)rely on symbiotic bacteria to ferment and break down cellulose of leaves
2) fermentation takes long time so colobine guts have slow passage of food through the guts
3) leaves yield very little energy so colobine’s stomach can store lots of leaves
Hominoidea -subdivision of the catarrhini
Distinguishing Hominoids (how are they different from other types of primates)
1) they lack tails
2) they have a distinctive Y-5 molar pattern (lower molars have 5 cusps with a Y ridge)-old world monkeys have bilophodont
molars
3) they have larger body sizes than other primates
4) they have larger brains size for their body size
5) they have brachiator anatomy
Brachiatory Anatomy characteristics
1) hominiods don’t use brachaition as main locomotion but CAN if they want to
2) a relatively flat and broad thorax (chest area)
3) a shortened trunk (shortened lumbar and vertebral region)
4) a scapula which has moved from the side of the body towards the back
5) joints of the shoulder, elbow and wrist which have developed to allow more mobility and flexibility of movements
6) longer forearms and longer fingers
Classifying apes
1) Hylobatidae(lesser apes)- gibbons and siamangs
a) only true brachiators
b) smallest of the apes (25 pounds-12 pounds)
c) strictly arboreal
d) fruitivorous
e) lives only in Southeast Asia
f) some possess ischial callosities
g) lots of calling to mark territories
h) little to no sexual dimorphism
i) monogamous-social group consist of single male, female and children (though does not reflect mating patterns)
2)pongdiae (greater apes)- orangutans, chimpanzees, and pan paniscus
a)
orangutans are found only on Borneo and Sumatra (two islands of Southeast Asia)
*highly sexual dimorphic: males weighs twice as much as females
*use suspensory climbing as locomotion
k) gorillas
 highly sexually dimorphic terms of body size
 some live in lowland jungle area and some live in mountainous areas.
l) chimpanzees
 live in a community-style social structure called a fission/fusion group( 30-60 individauls who constantly break up into
samller groups (fission) to feed and forage and then come back together (fushion) into larger groups for sleep and
protection at night)
 omnivorous-uses tools such as sticks to catch termites
Differentiating Old world vs New world Anthropoids
1) Location- new world monkeys are located in central and south America.
 had similar situation as lemurs of Madagascar- did not have to worry about competition amongst other primates. They
radiated out into more different niches.
2) New World monkeys have outward-facing nostrils and wide nasal septums while Old world monkeys have downward facing
nostrils and narrow nasal septums
3) new world monkeys lack the ischial callosities while Old world monkeys possess it.
4) new world monkeys has an ear ring( a ring bone around their inner ear) while old world monkeys have “Ear tube” (area of bone
which encloses the bones of the inner ear
5) New world monkeys have a 2-1-3-3 while old world has 2-1-2-3
6) New world are all arboreal (only occasional trips to the ground) while Old world exist in both arboreal and terrestrial forms
7) Some New world monkeys have prehensile tails( tails used for grasping) while No old world monkeys have prehensile tails
Callitrichidae vs Cebidae (2 subdivisions of the platyrrhini)
Cebidae Characteristics
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Cebids have a 2-1-3-3 dental formula
some cebids have prehensile tails (no callitrichid does)
cebids tend to have larger body size
cebids have one nocturanal genius- the Aotus genus (only noctural in the anthropoid family) –noctural niche occupied by
prosmians due to competitive niche
Callitrichidae characteristics
1) have a 2-1-3-2 dental formula
2) smaller body size
3) have claws instead of flat nails (claws are a derived charactersitic- modification of nails)
4) 80 % of callitrichid birhts are twins.
5) communal care of offspring, called ALLOCARE
Two main groups of Callitrichids
1) Marmosets- likely to concentrate more heavily on eating gums and saps
2) Tamarins concentrate on eating insects.
3) Tamarins also tend to live a little lower in the canopy
Goeld’s monkey- CALLIMICO
1) does not quite fit into the callitrichid/cebid disticions
2) they are small and have claws yet they have a 2-1-3-3 dental formula and give single births
Why new world monkeys are harder to study
1) new world monkeys are arboreal making it harder to study
2) people feels that old world monkeys are more related to humans and thus more important
Primate Behavior
Types of Primate Social Groups
1) One male-one single adult male, several adult femailes and their offspring.
a) most common primate structure
b) females usually from the permanent nucleus of the group
c) examples: guenons, gorillas, spider monkeys, pottos
2) Mutlimale/multifemale
a) several of the males reproduce
b) leads to tension and dominace hiearchy
c) examples: lemurs, macaques, squirrel monkeys, chimpanzees
3) Monogamous pair-mated pair and its young
a) usually arboreal
b) minimal sexual dimorphism
c) frequently territorial
d) adults do not tolerate adults of the same sex
e) exmaples: gibbons, owl monkes
4) Polyandry-one female and two males
a) seen only in new world monkeys( marmosets and tamarins)
5) solitary-individual forages for food alone
6) some adult females may forage in pairs or may be accompanined by offspring
7) examples: nocturnal prosimians, orangutans
Polyandry: a mating system wherein a female continuously associates with more than one male with whom she mates
Primate Evolution:
Era: Cenozoic -age of the mammals
Epoch: 1) Pleistocene
1.8mya
2)Pliocene
5mya
3) Miocene
22.5mya
4) Oligocene 34mya
5) Eocene
55mya
6) Paleocene 65 mya
Paleocene-warm and wet, angiosperms sprouted
1A) Others Adaptive radiation of primates-no fossils
1) Plesiadapiforms- fragmented fossils ( 2-1-3-3)
a)thought it was primate fossils but turned out to be not a primate
b) Found in N.America, Europe, Asia
c) it was actually related to the colugo (flying lemur)
d) it was important because
i) can tell what other animals are like back then
Purgatorius- 3-1-4-3 rounde Molar cusps ( more towards eating fruits and plants)
- ancestrial dental formula
2) Early Primate Landscape
a) late Mesozoic Era, a huge conglomerate landmass called Pangea began to break up northern and southern continents
b) To the north-Laurasia it became N.America, Europe, Asia
c) To the south-Gondwanaland-- it became Africa, S. America, Australia, India, Anartica
d) the two still connected thru Greenland
e) these landscape changes affected primates by:
i) bridge crossover led to primatelike mammals to be found in both N. America, and Europe
ii) climatic changes (Laurasia cooled and cooled climate even cooler by cutting off marine exchange between
North and South Sea
iii) Plant communities change. Rapid radiation of new plants such as flowering plants, deciduous trees, and grasses.
iv) insects became more abundant due to this increase in pollinous plants
3) Eocene Primates-Generally prosimians- warmer wetter, lots of forest (Europe and N. America Splits)
a) categorized in the Adapidae family-lemur like (2-1-4-3)
i) Cantius -- N. America and Europe
ii) Adapis – Europe
iii) Notharctus—N.America
iv) Smilodectes – N. America
b) Characteristics of the Adapidae family
i) complete postorbital bars
ii) larger rounder braincases
iii) nails instead of claws
iv) eyes that are rotated forward-binocular vision
v) grasping hands and feet
vi) developments of prehensitiliy are suggested
c) The OMOMYIDAE family-tarsier like(2-1-3-3 upper jaw) and (1-1-3-3- or 2-1-2-3)
i) don’t know if these evolved into modern primates
ii) pointed incisors( Shows they are Insectivors)
iii) Necrolemers
d) El Fayum-site of abundant fossil primate finds from the late Eocene and early Oligocine period
i) CATOPITHECUS genus
a) shared derived characteristic linking this genus to early anthropoids
b) closure of back of the orbits
c) fusion of the midline of the frontal into a single bone
d) rounded cusps on lower molar teeth
e) some derived features are also prosimian like (long snout and small brain)
4) Oligocene Primates-time of the first real monkey –Age of monkeys
a) the coldes epoch of the Cnozoic
b) forest shrinks-pushes primates south
c) monkey and apes did no split until 22mya.
d) characteristics of Oligocene monkey-like anthropoids
i) they had a reduced snout relative to the prosimians of the Eocene
ii) they manifest a decrease in the olfactory blub and increase in the visual cortex
iii) they show a larger brain relative tot Eocene primates
iv) they had a complete post orbital closure( first time we see this trait in primate evolution)
v) they were all arboreal quadrupeds
vi) they had a fused mandibular symphasis
vii) they are ominvores( eats everything from insects to fruits to leaves)
e) 2 groups of Oligocene Anthropoids
i) Parapithecidae (2-1-3-3)
a) retained more primitive, ancestral characteristics
b) 2 genera are APIDIUM and PARAPITHECUS
c) they are probably the stock group (ancestral) for New world monkeys
ii) Propliopithecidae (2-1-2-3)
a) stock group for Old World Monkeys, apes and humans
b) had a Y-5 Molar pattern
c) Y-5 Molar pattern is probably a ancestral, primative trait
d) bimodal distribution (shows sexual dimorphism)
e) 2 Genera are AEGYPTOPITHECUS and PROPLIOPITHECUS
iii) Branisella Boliviana- oldest primate found in New World.
a) Lyell uses the rafting hypothesis to explain how the monkeys got to the New world
b) molecular data shows it was during the Oligocene that the New and Old world monkeys separated
c) even today, sailors report seeing large mats of vegetation floating in the ocean
d) assume this is how lemurs got the Madagascar
5) Miocene Primates- age of the Hominoids- warming again, more forest
a) although only 6 genera of hominods (gibbons, orangutans, etc) during this period,there were at least 40
b) refered to as dental apes because they had modern ape dentition
c) look like apes in the head but like monkeys below the head ( did not have briachiator anatomy)
d) Africa Genera--Proconsulidae family
i) PROCONSUL- possessing a Y-5 dental pattern but lacks braichator anatomy
ii) MOROTOPITHECUS- had Y-5 Dental pattern but DID have braichator anatomy
e) Europe Genera- DRYOPITHECIDAE
i) DRYOPITHECUS- size of a chimp and may have been a brachiator AND lacked modern day hominoid
dental formula (dead end)
ii) OREOPITHICUSa) lived in swamps and swampy forest (uncommon for hominoids)
b) had a broad thorax
c) short lumbar region,
d) long forelimbs short hindlimbs( brachiator anatomy
e) had SIX cusps on their molars making them unlikely ancestors of modern hominoids
iii) OURANOPITHICUS- resemble the pongidae
f) Asian Genera- SIVAPITHECIDAE
i) SIVAPITHECUS- look like Orangutans but not brachiators but arboreal quadrupeds
ii) GIGANTOPITHECUS- estimated 1200lbs and 12 feet tall.
FINAL WORDS ABOUT PRIMATE EVOLUTION
1) prosimians split off about 60-50mya
2) new world vs old world monkeys split about 25-20MYA
3) gibbons and siamangs split off from the hominoids 15MYA
4) orangutans split off about 13 MYA
5) gorillas, chimps, humans split off about 7-5 MYA