Bio 100 - Study Guide 19
Human Evolution
The Primate Lineage
Human Evolution
The Primate Lineage
1.
2.
3.
4.
5.
Basic primate traits….humans
Primate phylogenetic tree
Species of Homo
Milestones of human evolution
Punctuated equilibrium human
evolution
Table of Mammal Characteristics
Trait
This means they can
Thermoregulation
Maintain and change body
temperature
Nutritional Efficiency
Eat and digest a lot to keep
themselves going
Locomotion and Posture
Move in many different ways
Multiple, Developed Life Stages
Spread growth and
development over a longer
period
Behavioral Flexibility
Change behavior to cope with
changes in the environment
They have
Hair to insulate, sweat glands
to cool off, and are ―warmblooded‖ so unlike reptiles, they
don’t have to be in a sunny spot
to stay warm
A hard palate that divides
chewing and breathing
apparatus so they can eat and
breathe at the same time, two
sets of teeth over the lifetime
and several different kinds of
teeth for different functions
A variety of options when
traveling through the
environment and seeking food
•Four main stages: In Utero
•Infancy
•Juvenile
•Adult
Humans add Childhood
between Infancy and Juvenile
A better chance of using
resources, surviving and
reproducing due to larger
brains
Distinguishing characteristics of primates include:
•Forward-facing eyes for binocular vision (allowing
depth perception)
•Increased reliance on vision: reduced noses, snouts
(smaller, flattened), loss of vibrissae (whiskers),
and relatively small, hairless ears
•Color vision
•Opposable thumbs for power grip (holding on) and
precision grip (picking up small objects)
•Grasping fingers aid in power grip
•Flattened nails for fingertip protection, development of
very sensitive tactile pads on digits
•Progressive expansion and elaboration of the
brain, especially of the cerebral cortex
http://www.serpentfd.org/section2hominidevolution.html
•Primitive limb structure, one upper limb bone, two
lower limb bones, many mammalian orders have lost
various bones, especially fusing of the two lower limb
bones
http://www.exploringnature.org/db/detail.php?dbID=24&detID=34
•Generalist teeth for an opportunistic, omnivorous diet;
loss of some primitive mammalian dentition, humans
have lost two premolars
Eruption time averages have been calculated among the general population (US). They are average values, so the
variation can range ±6 months
Average
"eruption" time
Teeth
(in months after
birth)
1) Lower central
incisor
8 months
2) Upper central
incisor
10 months
3) Upper lateral
incisor
11 months
4) Lower lateral
incisor
13 months
5) Lower first molar 16 months
6) Upper first molar 16 months
7) Upper canine
19 months
8) Lower canine
20 months
9) Lower second
molar
27 months
10) Upper second
molar
29 months
•Greater facial mobility and vocal repertoire
•Progressive and increasingly efficient development of
gestational processes
•Prolongation of postnatal life periods
•Reduced litter size—usually just one (allowing
mobility with clinging young and more individual
attention to young)
•Most primates have one pair of mammae in the chest
•Complicated social organization
Living Primates
• There are three main groups of
living primates:
– Lemurs, lorises, and pottos
– Tarsiers
– Anthropoids (monkeys and
apes)
Millions of years ago
0
10
20
60
30
40
50
Ancestral primate
Humans
Chimpanzees
Gorillas
Orangutans
Gibbons
Old World monkeys
New World monkeys
Tarsiers
Lemurs, lorises, and pottos
LE 34-38
Anthropoids
Sifaka, a type of Lemur
LE 34-39
New World monkeys, such as spider
monkeys (shown here), squirrel monkeys,
and capuchins, have a prehensile tail and
nostrils that open to the sides.
Old World monkeys lack a prehensile tail,
and their nostrils open downward. This
group includes macaques (shown here),
mandrills, baboons, and rhesus monkeys.
LE 34-40a
Gibbons, such as this Muller’s gibbon, are found
only in southeastern Asia. Their very long arms
and fingers are adaptations for brachiation.
LE 34-40b
Orangutans are shy, solitary apes that live in the rain forests of
Sumatra and Borneo. They spend most of their time in trees;
note the foot adapted for grasping and the opposable thumb.
LE 34-40d
Chimpanzees live in tropical Africa. They feed and sleep in
trees but also spend a great deal of time on the ground.
Chimpanzees are intelligent, communicative, and social.
LE 34-40c
Gorillas are the largest apes:
some males are almost 2 m tall
and weigh about 200 kg. Found
only in Africa, these herbivores
usually live in groups of up to
about 20 individuals.
LE 34-40e
Bonobos are
closely related
to chimpanzees
but are smaller.
They survive
today only in the
African nation of
Congo.
Anthropoid
Hominoid
Hominid (pl. Hominin)
• Hominids originated in Africa about 6–7
million years ago
• Early hominids had a small brain but
probably walked upright, exhibiting mosaic
evolution
• The fossil record has 20 species of
extinct hominids
• Two common misconceptions about
early hominids:
– Thinking of them as chimpanzees
– Imagining human evolution as a
ladder leading directly to Homo
sapiens
LE 34-41
Homo
Homo
neanderthalensis sapiens
Paranthropus
robustus
0
Paranthropus
boisei
0.5
Homo
ergaster
?
1.0
Australopithecus
africanus
1.5
Millions of years ago
2.0
2.5
3.0
Kenyanthropus
platyops
Australopithecus
garhi
Homo
erectus
Australopithecus
anamensis
3.5
Homo
rudolfensis
4.0
4.5
5.0
Ardipithecus
ramidus
Australopithecus
afarensis
5.5
6.0
6.5
7.0
Orrorin tugenensis
Sahelanthropus
tchadensis
Homo
habilis
1 HOMO HABILIS ~ NICKNAME: Handyman LIVED: 2.4 to 1.6 million years ago
HABITAT: Tropical Africa DIET: Omnivorous nuts, seeds, tubers, fruits, some meat
2 HOMO SAPIEN ~ NICKNAME: Human LIVED: 200,000 years ago to present
HABITAT: All DIET: Omnivorous - meat, vegetables, tubers, nuts, pizza, sushi
3 HOMO FLORESIENSIS ~ NICKNAME: Hobbit LIVED: 95,000 to 13,000 years ago
HABITAT: Flores, Indonesia (tropical) DIET: Omnivorous - meat included pygmy
stegodon, giant rat
4 HOMO ERECTUS ~ NICKNAME: Erectus LIVED: 1.8 million years to 100,000
years ago HABITAT: Tropical to temperate - Africa, Asia, Europe DIET: Omnivorous meat, tubers, fruits, nuts
5 PARANTHROPUS BOISEI ~ NICKNAME: Nutcracker man LIVED: 2.3 to 1.4
million years ago HABITAT: Tropical Africa DIET: Omnivorous - nuts, seeds, leaves,
tubers, fruits, maybe some meat
6 HOMO HEIDELBERGENSIS ~ NICKNAME: Goliath LIVED: 700,000 to 300,000
years ago HABITAT: Temperate and tropical, Africa and Europe DIET: Omnivorous meat, vegetables, tubers, nuts
7 HOMO NEANDERTHALENSIS ~ NICKNAME: Neanderthal LIVED: 250,000 to
30,000 years ago HABITAT: Europe and Western Asia DIET: Relied heavily on meat,
such as bison, deer and musk ox
http://rst.gsfc.nasa.gov/Sect20/A12c.html
http://rst.gsfc.nasa.gov/Sect20/A12c.html
LE 34-42b
Upright
posture
evolved
before a
Large Brain
The Laetoli footprints, more than
3.5 million years old, confirm that
upright posture evolved quite
early in hominid history.
Larger Brains Mark the Evolution of Homo
http://brainmind.com/LeftHemisphere.html
Derived Characters of Hominids
• A number of characters distinguish humans
from other hominoids:
–
–
–
–
–
–
Upright posture and bipedal locomotion
Larger brains
Language capabilities
Symbolic thought
The manufacture and use of complex tools
Shortened jaw
Climate played a role in the evolution and
migration of hominids. Warm periods, and
especially ice ages, were prime factors.
http://rst.gsfc.nasa.gov/Sect20/A12c.html
Australopiths
• Australopiths are a paraphyletic assemblage
of hominids living between 4 and 2 million
years ago
• Some species walked fully erect and had
human-like hands and teeth
LE 34-42a
Lucy, a 3.24-million-year-old
skeleton, represents the
hominid species
Australopithecus afarensis.
LE 34-42c
An artist’s reconstruction of what A. afarensis may have looked like.
Early Homo
• The earliest fossils placed in our genus Homo are
those of Homo habilis, ranging in age from about
2.4 to 1.6 million years
• Stone tools have been found with H. habilis, giving
this species its name, which means ―handy man‖
• Homo ergaster was the first fully bipedal,
large-brained hominid
• The species existed between 1.9 and 1.6
million years ago
• Homo erectus originated in Africa about
1.8 million years ago
• It was the first hominid to leave Africa
Neanderthals
• Neanderthals, Homo neanderthalensis, lived
in Europe and the Near East from 200,000
to 30,000 years ago
• They were large, thick-browed hominids
• Neanderthals became extinct a few
thousand years after the arrival of Homo
sapiens in Europe
Homo sapiens
• Homo sapiens appeared in Africa at least
160,000 years ago
• The oldest fossils of Homo sapiens
outside Africa date back about 70,000
years ago
http://creationwiki.org/Human_migration
The End