1. Human Evolution

2. Homo Neanderthalensis
Homo Sapiens
Homo Neanderthalensis
Homo Erectus
Homo
Heidelbergensis
Homo Habilis
Homo Robustus
Homo Ergaster
Maybe add in an inquiry piece about asking students what makes humans unique, not only cognatively, but also physically? (upright, color vision, opposable thumbs etc)
Australopithecus
Africanus
Paranthropus
Aethiopicus
Australopithecus
Afarensis

3. Australopithecus anamensis 4.2 to 3.9 million years ago
History of Man
SPECIES
TIME PERIOD
Ardipithicus ramidus
5 to 4 million years ago
Australopithecus anamensis
4.2 to 3.9 million years ago
Australopithecus afarensis
4 to 2.7 million years ago
Australopithecus africanus
3 to 2 million years ago
Australopithecus robustus
2.2 to 1.6 million years ago
Homo habilis
Homo erectus
2.0 to 0.4 million years ago
Homo sapiens archaic
400 to 200 thousand years ago
Homo sapiens neandertalensis
200 to 30 thousand years ago
Homo sapiens sapiens
200 thousand years ago to present

4. Earliest Ancestors Plesiadapis: 60 mya one of the oldest known primate
-like mammal species
Mainly lived on the ground
However, it was a good climber.
It was an arboreal quadruped.
It was a tree-moving, 4-legged animal.
What was the selective pressure for our
ancestors to evolve?
What happened about 65 mya?
Why were they more fit than dinosaurs
in the changing environment?

5. Primate Evolution Prosimians: 55 mya Generally nocturnal,
generalized diets.
Includes lemurs, lorises, bushbabies.
Emergence of opposable thumb.

6. Short or absent tail (not prehensile)
Primate Evolution
New World Monkeys
Lateral nostrils
Prehensile tail
Old World Monkeys
Downward nostrils
Short or absent tail (not prehensile)
Why did they diverge? (Geographic isolation)
Why did they diverge?
Because they were reproductively and geographically isolated from each other by the
growing separation between the African and South American continents.
So as those two continents moved apart, climates changed and new selectional pressures
arose.

7. Primate to Hominid Evolution
Old World Monkeys
New World Monkeys
A subset of old world monkeys. All of the
same differences from new world monkeys
but an extra set of differences unique to
hominoids.
Hominoids
Part of the superfamily Hominoids.
Specifically include:
- humans
- orangutans
- gorillas
- chimpanzees
Hominids

8. Hominid Evolution - Jaws: humans have a bowed jaw,
Key Characteristics of Hominids (chimpanzees, gorillas, humans, and orangutans):
- Jaws: humans have a bowed jaw,
rather than a U- shaped.
- Apes have diastema (spaces
between teeth), we lack diastema.
- Skeletal changes associated with bipedality
- Cranial changes – development of forehead
- Loss of brow ridges
- Loss of sagittal crest – the ridge of bone
running lengthwise along the midline
of the top of many mammalian skulls.
Define terms for them… hominid, homo, etc.

9. explanations for bipedalism.
Hominid Evolution
Key Characteristics of Hominids (chimpanzees, gorillas, humans, and orangutans):
- Skeletal changes associated with bipedality
Why?
Climate/environmental change – forests began to shrink and savannah began to expand
Define terms for them… hominid, homo, etc.
Take a moment and
write down possible
explanations for bipedalism.

10. Hominid Evolution
Key Characteristics of Hominids (chimpanzees, gorillas, humans, and orangutans):
- Loss of sagittal crest – the ridge of bone
running lengthwise along the midline
of the top of many mammalian skulls.
Define terms for them… hominid, homo, etc.
Animals that do a lot of heavy chewing have a sagittal crest. It is needed for exceptionally
Strong jaw muscles.
Take a look at the sagittal crest on the right. It takes up a lot of room on the head and skull.
If we no longer had the huge crest on the top of the head, what would be allowed to happen?
We now have room to expand our skulls and, therefore, our brains!

11. Lucy: Australopithecus afarensis
Hominid Evolution
Lucy: Australopithecus afarensis
3.6 – 2.9 mya
1 meter tall
Bipedal
Partly arboreal
Ape-like face with
sloping forehead
What was selected for? - Bipedalism Why? Environmental change. Let’s lead them to these ideas.

12. Hominid Evolution Australopithecines: 2.2 mya
Bipedal, dentally similar to
humans but smaller brain - Slender
Some may have used
tools
Extension of cool,
dry, savannah habitat

13. Hominid Evolution Now we start with the Homo line of Hominid Evolution
The organisms we will talk about will
have a two part name: Homo _______
Homo refers to our genus
(which includes humans and our close relatives).
The second part of the name identifies the species.

14. Hominid Evolution Homo habilis: 2.4 – 1.6 mya
Similar to australopithecines
Because face is still primitive
Smaller face, jaw and teeth
Larger cranial capacity
Primitive stone tools

15. Hominid Evolution Homo Erectus: 1.8 – 0.3 mya
Similar to habilis: protruding
jaws with large molars, no chin
thick brow ridges, a long low
skull.
More advanced tools.
Spread from Africa to Europe
and Asia.

16. Hominid Evolution Homo neanderthalensis: 230,000-30,000 years ago
By 130,000 years ago, following a
prolonged period of independent evolution
in Europe, Neanderthals were so anatomically
distinct that they are best classified as a
separate species
This is a great example of geographic isolation
leading to a speciation event.
Brain larger than modern humans.
Midfacial area protruded perhaps an
adaptation to cold.
-Short and solid with short limbs because of the cold.

17. Hominid Evolution
Homo sapiens sapiens:
modern

18. Out – of – Africa Theory
Modern humans evolved relatively recently in Africa, migrated into Eurasia and replaced all populations which had descended from Homo erectus.
- after Homo erectus migrated out of Africa, the different populations became reproductively isolated, evolving independently, and in some cases like the Neanderthals, into separate species
- Homo sapiens arose in one place, probably Africa (geographically this includes the Middle East)
- Homo sapiens ultimately migrated out of Africa and replaced all other human populations, without interbreeding
- modern human variation is a relatively recent phenomenon
We know this is true because every single human being across the planet has the
same innate and learned behavior skill set.
We can also interbreed successfully with humans across the planet.

19. So what are vestigial “organs”?
Homologous structures of organisms that have
seemingly lost all or most of their original function in a species through evolution.
Can you think of any vestigial “organs” or behaviors?
Tail bone
Goose bumps in terms of defense.
Infants will instinctively grasp any object which touches the palm ancestral primates would have had sufficient body hair for an infant to cling to, allowing its mother to escape rapidly from danger.
Moro reflex
Ear muscles
Babies can swim before they walk
Wisdom teeth
Pruney fingers