Kingdom- Animalia, Phylum- Chordata, Class- Mammalia,
Order-- Primates
• appeared around 50-55 million years ago
– 10-15 million years after the dinosaurs had become
extinct
– similar to squirrels in size and appearance
– adapted to an arboreal way of life in warm, moist
climates
– First Primates (13:04)
• http://www.pbs.org/wgbh/nova/evolution/firstprimates.html
• the order primates includes humans, apes,
monkeys, and prosimians
• sexually dimorphic--physical differences between
the sexes other than the sex organs
• 230-270 species
– consists of two major suborders: the Prosimii and the
Anthropoidea
• 48% of primate species are in danger of extinction
within the next decade
• all of the primates (except spider monkeys) have
retained the ancient mammalian trait of
pentadactylism (five fingers on hands and feet)
– fingers and toes are mobile and have very sensitive
tactile pads at the tips
– the grasping, or prehensile,
ability of primate hands varies
as does the degree of
opposability of the thumb
• has been a progressive reduction in nose size
and in the olfactory areas of the brain
– of approximately 1,000 human olfactory receptor
genes, only 347 remain functional-- the rest have
mutations that deactivate them
• has been an increase in visual capabilities
– all have binocular vision with fields of view that
significantly overlap, resulting in true three
dimensional (3-D) depth perception or stereoscopic
vision
Human eyes have an overlapping field of view
of about 120 degrees. It is only in this field that
we have stereoscopic vision. Beyond this 3-D
area out to 160-180 degrees, we see things
only in two dimensions (2-D)--i.e., flat without
depth. Monkeys and apes have about the same
depth perception ability as humans, but the
eyes of lemurs are farther apart resulting in a
smaller overlapping field of view.
• tendency to stand upright
• compared to most other animals, primate brains
are large relative to their body size
– encephalization quotient
• a measure of relative brain size defined as the
ratio between actual brain mass and predicted
brain mass for an animal of a given size
• generally have long gestation periods (pregnancies)
for animals of their size
– offspring are born more mature and therefore, have a
greater chance of survival
• almost all primates are diurnal
• highly social animals
• intelligent and opportunistic in getting food
• most are unusually adaptable in diet which
has tremendous evolutionarily selective
value
• Behavior
– for most animals, behavioral patterns are
predominantly determined by genetics
– in contrast, a large part of primate behavior is
learned
• therefore, can change dramatically in relatively short time
• Chimps Batter Hives for Honey (2:11)
– communicate with smells, sounds, visual messages,
and touching
– use their environment as it is, without modification
(except humans)
Suborder– Prosimii
• lemurs, lorises, and related animals
– the name lemur comes from an ancient Latin word,
lemures, which refers to frightening spirits of the
dead who haunt people at nighttime
– Ring-tailed lemures (:31)
– more than half of the lemur species are on the verge
of extinction due to habitat destruction
47 million year old Adapidae fossil from Germany
(much of the soft tissue, including fur, is fossilized)
• major evolutionary changes
were beginning in some early
prosimians that foreshadow
species yet to come
– foramen magnum- a hole through which the
spinal cord passes
– the position of the foramen magnum is a strong
indicator of whether the body is habitually
horizontal (like a horse) or vertical (like a
monkey)
• this suggests that they were beginning to hold their
bodies erect while hopping and sitting
Suborder-- Anthropoidea
• at least 145 living species
– over 90% of them are monkeys
– remaining species are apes and humans
• have been the most successful primates in
populating the earth
• two distinct infraorders of Anthropoidea that have
been evolving independent of each other for at
least 3 million years
– Platyrrhini (New World monkeys)
– Catarrhini (Old World monkeys, apes, and humans)
Platyrrhini -- New World Monkeys
• predominantly arboreal and mostly
herbivorous
• have nails on all of their fingers and toes
• Helping Hands with Capuchin Monkeys (2:19)
– http://www.youtube.com/watch?v=iEpJf5-IYwM
Catarrhini -- Old World Monkeys
• relatively large compared to New World
Monkeys
– other than Hominids, most familiar are the African
baboons.
Superfamily- Hominoidae
• mostly apes and humans
• Did humans evolve from apes (5:33)
–
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http://www.pbs.org/wgbh/evolution/library/11/2/real/e_s_5.html
the largest primates
all digits have flattened nails
short or no tail
have large braincase
dental formula is the same for all
Hominid Family Tree (2:17)
–
http://www.youtube.com/watch?v=C_o9j00Yp98
Family- Pongidae (the
great apes)
• differ from other primates in that they lack
external tails
• more intelligent and more dependent for
survival on learned behavior patterns
• gibbons, orangutans, gorillas, chimpanzees,
and bonobos, and humans)
• chimpanzees
– more closely resemble humans than do the
gorillas
– most successful of all apes in that there are more
of them and they have the widest geographic
range
– chimpanzees live in fluid societies of 10-50
individuals.
– chimpanzees do not form monogamous mating
bonds
– http://www.youtube.com/watch?v=WDFh5JdYh7I
Madeleine
Family- Hominidae (humans)
• has been historically difficult for people to
accept that we are in fact just another
primate species with African origins
• habitual bipeds
• unlike apes, arms are short and weak
compared to our legs
• feet have lengthened and acquired an arch
(early fossil record contains no foot bones) making them better
body supports
• longer legs require less up-and-down
movement while running and therefore,
reduce the amount of energy
• have 46 chromosomes in their cells while all of
the great apes have 48
• human chromosome #2 is a fusion of ape
chromosomes #12 and #13 with most of the same
genes
– http://anthro.palomar.edu/primate/videos/evol07_
vid_genconnect.html (3:27)
• 98.77% of DNA base pairs of humans and
chimpanzees are the same
– http://www.youtube.com/watch_popup?v=WBEtw7
esmvg&vq=medium#t=14 (1:40)
• we differ in the genes that control speech,
smelling, hearing, digesting proteins, and
susceptibility to certain diseases
• volume of modern human brain is 3 times larger
than great apes
• human brain uses about 25% of the energy
derived from the nutrients that we consume and
20% of the oxygen
– http://www.youtube.com/watch?v=9JvNwEMXLD8 (7:27)
• only primate species that now lacks a thick
insulating fur over our entire bodies
– allows humans to cool efficiently by the
evaporation of sweat
• the only species of primate in which all older
females go through menopause and become
sterile
– post-menopausal women around the world often
take care of their grandchildren while their
daughters are working
– argued that this increases the chances that the
grandchildren will survive to adulthood
• Use with Hominid PowerPoint
• http://www.youtube.com/watch?v=awKl8eEv
Ktw
• http://www.youtube.com/watch?v=zohMSNp
W91k&NR=1