Transcript Human Evolution II

V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
“slender”
species
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
“slender”
species
“robust”
species
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
Primitive species, with their bipedality
disputed. Are they on the human line?
The chimp line? Ancestral to both?
Can’t tell – they are so
INTERMEDIATE….
Morphological cladogram
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
- The distinguishing traits of hominids are
erect gait and large brain.
And, as we’ve discussed, Australopithecus afarensis
walked erect.
And, as we’ve discussed, Australopithecus afarensis
walked erect.
A. Afarensis prints at
Laetoli, approximately 3.56
myr, were made by an
obligate biped:
- heel strike.
- Lateral transmission of
force from the heel to the
base of the lateral
metatarsal.
- A well-developed medial
longitudinal arch.
- Adducted big toe, in front of the ball of the foot
and parallel to the other digits.
- A deep impression for the big toe commensurate
with toe-off.
- A tibia from A. anamensis found in 1994 is
oldest direct evidence of bipedality (4.1 mya)
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
- The distinguishing traits of hominids are
erect gait and large brain.
- Erect gait came first…
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
- The distinguishing traits of Hominids are
erect gait and large brain.
- Erect gait came first…
- Brain size increase was later, particularly
with Homo habilis and H. erectus..
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
VII. Why did these changes occur?
VII. Why did these changes occur?
- Walking Erect: Adaptive in the expanding dry
grasslands.
VII. Why did these changes occur?
- Walking Erect: Adaptive in the expanding dry
grasslands.
VII. Why did these changes occur?
- Increased Brain Size:
- walking erect frees the hands for activity
- With tools use (seen in Homo habilis),
animals could be killed. This increases protein in
diet, needed for growth (particularly the brain).
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
VII. Why did these changes occur?
VIII. And what of our species?
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils,
genetic variability, etc.)
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils,
genetic variability, etc.)
- Bands of hunter gatherers
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils,
genetic variability, etc.)
- Bands of hunter gatherers
- Cave Art about 30,000 years ago
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils,
genetic variability, etc.)
- Bands of hunter gatherers
- Cave Art about 30,000 years ago
- 14,000 years ago, bands settled in different areas
of the globe and began to grow local crops.
First Agricultural Revolution….
Where and when:
Fertile
Crescent
Eastern U. S.
Sahel?
Mesoamerica
Amazon?
Andes
West
Africa?
Ethiopia?
China
New
Guinea
HUMAN PREHISTORY – Where did humans come from?
agriculture
burial
5.0 mya
75,000
14,000
99.6% before art
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
VI. When did these changes evolve?
VII. Why did these changes occur?
VIII. And what of our species?
IX. Evolutionary patterns and new stuff!
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- common ancestry from primitive forms
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- common ancestry from primitive forms
- new innovation in new environment (bipedality as
climate changed…)
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- common ancestry from primitive forms
- new innovation in new environment (bipedality as
climate changed…)
- radiation of species with this trait (bipedalism)
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- common ancestry from primitive forms
- new innovation in new environment (bipedality as
climate changed…)
- radiation of species with this trait (bipedalism)
- competitive contraction and a winner (H. sapiens)
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- New Stuff!
Nature
Oct 28, 2004
- And there are new surprizes all the time…
Homo floresiensis – Nature, Oct. 28, 2004
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- New Stuff!
Island species are often either dwarf species or giant
species:
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- New Stuff!
Island species are often either dwarf species or giant
species:
- dwarf because resources might be limiting
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- New Stuff!
Island species are often either dwarf species or giant
species:
- dwarf because resources might be limiting
- giant if niches are open
IX. Evolutionary patterns and new stuff!
- Hominids provide all the classical patterns of
evolution seen in the rest of life:
- New Stuff!
- Conclusion:
Rather than lacking evidence, the history of humans
provides one of the BEST examples in support of
evolution by common descent.