ASU Hominoid Origins Part one Slide Shows

The slide show begins with an overview of primate evolution, setting the stage for understanding where hominoids fit within the larger primate family tree. It defines key terms such as hominoids (superfamily Hominoidea), which includes both apes (chimpanzees, gorillas, orangutans, and gibbons) and humans, as well as hominins, the subset of hominoids that are more closely related to modern humans than to other apes.

1. Apes Humans
HOMINOID ORIGINS

2. Old World
Monkeys Apes
Humans
loss of tail

3. Old World
Monkeys HumansPongo GorillaPanHylobates
Divergence times based
on nuclear DNA data
(Stauffer et al., 2001)
~23 mya
~15 ±2 mya
~11 ±1.5 mya
~6.5 ±1.5 mya
~5.4 ±1.1 mya
M I O C E N E
(23
-5.3
mya
)

4. §Earliest evidence of fossil apes comes from Africa
§In the early Miocene (22 –17 mya) there was great
diversity of fossil apes –more than 10 genera and
15 species known
§This is the first of two adaptive radiations of apes
in the Miocene
§Multiple species found at some sites including
Proconsul and other “small” apes (3.5 –10 kg)
Where and when did
apes evolve?

5. Early Miocene
§Thediversityof primates
is characteristic of
present-day tropical
forest environments
§East Africa was probably
heavily forested in the
Early Miocene
§But there were fewer
monkey speciesthan ape
species

6. §20 million years ago
§East African Rift
Valley is forming
§Highlands not
yet formed, so
rain from
Atlantic and
Indian Oceans
keeps things
wet
§Volcanic activity
East Africa in the
Early Miocene

7. HOMINOIDS
Dryopithecus-pattern

8. HOMINOID POSTCRANIAL
ADAPTATIONS
Hominoids—orthograde
suspensory, knuckle-
walking, bipedalism
Monkeys—pronograde
quadrupedalism

9. Apes: increased shoulder,
hip, wrist, and ankle
mobility; no tail; long upper
limbs; short, stiff back
Orangutan
Mandrill

10. Proconsul
§Kenya –Rusingaand MfawanganoIslands in Lake
Victoria; Songhor; Koru
§4 species
§20 –17 mya
Lightly built
cranium
No supraorbital
torus
Prognathic
Sexually dimorphic
canines
Molars w/ Y-pattern
Monkey-like head

11. Proconsul
§Body size dimorphism:
Males 1.3x as large as
females
§MOSAICpostcranial
morphology
(monkey-like + ape-like
characteristics)
§Morphology suggests
arboreal
quadrupedalism for at
least 2 of the species
§NO SUSPENSORY
MORPHOLOGY
§NO EVIDENCE OF
A TAIL

12. Old World
Monkeys HumansPongo Gorilla PanHylobates
Proconsul
reduction in # of lumbar
vertebrae
loss of tail
increased shoulder mobility
Y-pattern on molars