Primate Evolution
Section 16.1 Primates
Daily Objective
• Understand that Primates share several
behavioral and biological characteristics,
which indicates that they evolved from a
common ancestor.
16.1Primates
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Humans
Apes
Lemurs
Monkeys
Characteristics of Primates
• Manual Dexterity- flexible hands and feet. The first
digits on Primates hands and feet are opposable.
Opposable first digit; either a toe or thumb is set
apart from the other digits.
• Senses- Binocular vision allows for primates to have a
greater field of depth perception and better
judgment of relative distance and movement of an
object. Most primates are diurnal; active during the
day and have color vision. Primates that are
nocturnal have black and white vision.
Characteristics of Primates cont..
• Locomotion- Primates have flexible bodies
and limbs. When on the ground all Primates
but Humans walk on all four limbs.
• Complex brain and behaviors- Primates tend
to have large brains in relation to their body
size. Many primates have problem-solving
abilities, and well developed social behaviors.
i.e. grooming and communicating.
Characteristics of Primates cont..
• Reproductive rate- Most
primates have fewer
offspring than other
animals, and the majority
of Primates have single
births at one time.
Compared to other
mammals pregnancy is
long, and infants depend
on the mothers for a
great amount of time.
Primate Geographic Distribution
• Non-human primates live in tropical regions. The loss of habitat is
threatening populations in those areas.
Primate Groups
• Primates are a large diverse group of more than
200 living species. They are divided into two sub
groups.
Strepsirrhines- “the wet-nosed
group”
The most “basic” subgroup. Includes
the Lemur.
Haplorhines- “dry-nosed”
Includes large-brained diurnal
monkeys and hominoids
(gibbons, orangutans,
chimpanzees, gorillas, and
humans.)
Where do Humans fit in?
• Humans are included in the
great ape family. They are
then classified in a separate
subcategory of hominids
called hominins. Hominins
are humanlike primates
that appear to be more
closely related to presentday humans than they are
to present-day
chimpanzees and bonobos.
Only one species survives
today.
Primate Evolution
• Arboreal adaptation- many scientists
speculate that primates evolved from a
ground-dwelling animal.
• Primate ancestors- Data suggests that the first
primates lived about 85mya, when dinosaurs
roamed the earth (Cretaceous period) But
fossils do not appear until 60 mya (Eocene
epoch)
Primate Evolution cont..
• Diverging primates- Sometime around 50mya
the anthropoids (great apes) diverged from
the tarsiers (haplorhines primates)
• Displacement- Many early strepsirrhines
were exctinct by the end of the Eocene epoch.
It is a thought that since the arthropoids were
larger and had bigger brains, that they
outcompeted some of the strepsirrhines
species for resources.
Primate Evolution cont…
• The appearance of
monkeys occurred at the
end of the Eocene.
Monkeys are split into two
categories; Old world and
New World monkeys.
• Scientists hypothesize that
the New World Monkeys
diverged from the line that
gave rise to the Old World
Monkeys between 35 and
25 mya.
Daily Objective
• Describe several Hominoids and Hominin
features
Section 16.2 Hominoids to Hominins
• Describe hominoid and hominin features
Hominoid characteristics
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They are the largest primates.
Largest brain size to body ratio.
Broad pelvises
Long fingers
No tail
Non-specialized teeth. (Their molars have
distinctive pattern scientists use to distinguish
hominoid fossils from other primates.)
A few facts about hominoids
• Include all nonmonkey anthropoids- the living
and extinct gibbons orangutans, chimpanzees,
gorillas, and humans.
• The earliest hominoid fossils appear in the
fossil record only about 25 mya at the
beginning of the Miocene. (middle of
Cenozoic)
• The fossil record for hominoids is so sparse, so
scientists also examine biochemical data.
They compare the DNA of living hominoid
species and researchers conclude that gibbons
likely diverged first from an ancestral
anthropoid, followed by orangutans, gorillas,
chimp, bonobos, and finally, humans.
• Chimpanzees and bonobos are the closest
living relatives to humans. All three share at
least 96% of their DNA sequences.
• The human lineage and the chimp lineage
diverged about 6 mya.
Hominin Characteristics
• Hominins have big brains with more
complexity in parts of the brain where highlevel thought occurs.
• Thinner, flatter face
• Smaller teeth
• Lengthened thumbs, flexible wrists, and
manual dexterity
• Bipedal- they can walk upright on two legs
Hominin cont..
• Homo sapiens (us) evolved around 200,000 years
ago and were preceded by several other species
of Hominin.
• A hominin is any species that is more closely
related to a human than a chimpanzee.
Meet Lucy!
• http://www.youtube.com/watch?v=3a7wSKK8lh4
Daily Objective
• Investigate the comparison between DNA of
humans, chimpanzees, gorillas, and “a
common ancestor”
• Procedure
• 1) “synthesize DNA strands according to the
following specifications. Each different color of
paperclip represents one of the four bases of
DNA.
Adenine (A) =
Guanine (G)=
Thymine (T)=
Cytosine (C)=
• You are synthesizing DNA strands by
connecting paper clips in the proper sequence
according to specifications listed by each
group member. When you have completed
your synthesis attach a label to Position 1 and
lay your strands on the table with Position 1
on the left.