The Origins and Evolution of early - PowerPoint Presentation

Slide1

The Origins and Evolution of early Homo

Chapter

8Slide2

Introduction

What separates hominins from hominids? (the humans from the apes)

One thing is tool use

Chimpanzees and other primates use tools, but not to the extent that humans doSlide3

introduction

For the rest of the fossils we study (the genus

Homo

) we will use the

biocultural

approach

We will look at anatomy and features

And we will look at behavior and cultureSlide4

Introduction

Traditionally there

was debate

over whether Asia or Africa is the origin of humans

When a fossil ancestor skull was found in Asia in the 1800s, people thought that Asia was our birthplace

Now we know Africa is, and that our ancestors

migrated out of Africa and around the worldSlide5

Earliest ancestors

Today we will focus on two of the earliest human ancestors:

Homo

habilis

Homo erectusSlide6
Slide7
Slide8

Splitters vs lumpers

Some scientists see each anatomical difference as valid and make many species

Some see lots of variation and group fossils together

I am more of a

lumper

but do split a few things Ex.

Paranthropus

is its own groupSlide9

Family tree

We have discussed early primates, the Australopithecines,

Paranthropus

, and now we move the

genus

Homo

All species in this genus are humanlike; they make tools and are intelligent, but still do not have large brainsSlide10

Homo habilisSlide11

Homo habilis

Modern humans rely on technology to survive, but our ancestors had to rely on their bodies and brains

Fossil skulls were found near

Paranthropus

but had bigger brains and more human-like trends

Rounder skull

Smaller teeth

Nonhoning

canineSlide12

Trends

We will focus on continuing trends in this genus, but

both biological

and cultural

Biology:

Teeth get smaller

Face gets flatter

Skull gets rounderSlide13

Homo habilisSlide14

Homo habilis

Means “Handy Man”

First

hominin

known to use stone tools

2

mya

Small body, short legs,

bidpedal

, similar to

Australopithecines

but slightly larger brains

Important: they also had

hands that could manipulate toolsSlide15
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Homo habilis: intelligence and tool use

Hand: precision grip

Brain: slightly larger size

(650 cc)

Use of reason, strategy, planning

Small teeth and weak chewing power show that tools were important for

habilis

’

survival

As tools become more important, teeth and chewing muscles get weakerSlide17

Homo habilis

It is not just about brain

size

, but also about brain

shape

Post-orbital constriction

shows growth of frontal lobeSlide18

Homo habilis

It is not just about brain

size

, but also about brain

shape

Post-orbital constriction

shows growth of frontal lobeSlide19
Slide20

Habitat

Warm season with grasses and diverse habitats

Increased food resources

 increased exploitation of resources

Tools would help them exploit land

Digging roots and tubers

Processing food

Possible scavengingSlide21

Tool technique

Olduwan

tools:

Part of the

Lower

Paleolithic

Technique

Crude, simple

But show manipulation of materials for specific purposeSlide22

Homo erectus

A new species appeared 1.8

mya

Finally get a

l

arger brain

Large brow ridges

Both

H.

habilis

and

H. erectus

originated in Africa, but some

H. erectus

migrated to AsiaSlide23

Split?

Some split

H. erectus

and

H.

ergaster

Fossils found in Africa are

ergaster

Fossils found in Asia are

erectus

I will refer to them all as

H. erectusSlide24
Slide25

Homo erectus

Important anatomical features:

Sagittal keel

: bump on top of skull because brain is asymmetrical

Wide part of skull is at the base: “mushroom-shaped head”Slide26

Homo erectusSlide27
Slide28

trends

Teeth small

Small brain

Small

browridge

Small body

Long arms

Short legs

Teeth smaller

Larger brain

Larger

browridge

Tall body

Shorter arms

Longer legs

Homo

habilis

Homo erectusSlide29

Homo erectus in africa

Earliest record is about 1.8

mya

Nariokotome

Boy/Turkana Boy

: full skeleton that shows modern anatomy (*in video*)

Longer legs means this was a true biped (no more utilizing trees)

Adolescent male who would have been more than 6 feet tall

900 cc brainSlide30

Nariokotome boySlide31

Homo erectus in asia

Began to migrate soon after evolving in Africa

First fossil is

Dmanisi

skull, found in the Republic of

Georgia

Zhoukoudian

in ChinaSlide32

Homo erectus in asia

Widespread

migration through Asia

Survived for

more than 1 million years

, so very successful

One skull found has marks on bone: either cannibalism or body modificationSlide33

fire

H. erectus

is the first

hominin

thought to have

used fire

Benefits:

Keep warm

Stay safe (scar away predators)

Cook food (fewer parasites and easier to chew)

Cooking food also releases more nutrients

Extend daylight (more time for cultural behaviors)Slide34

Adaptations

From

H.

habilis

to

H. erectus

,

males’ heights increased 33% and females’ 37% in 200,000 years

Much of this probably because of increase in animal proteinSlide35

adaptations

However,

there is debate over whether

erectus

was a

scavenger or a

hunter

Keep this in mind when watching video and doing extra credit

The video discusses exhaustion hunting

The tools they made were not hunting weapons

So they were scavengers (at least at first

), and then became huntersSlide36

Tool technique

Acheulian

tools

Still Lower

Paleolithic

More complex than

habilis

’

Handaxe

: sharp edge for cutting and scraping (good for scavengers)

More refined: showed higher level of skillSlide37
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