Human Evolution

Mrs. Nelson

Background Information…

What does evolution mean?

- “change”

Who was Charles Darwin?

-evolution and natural selection

What did Charles Darwin say about human evolution?

-Humans and apes shared a common ancestor

-Problem was he had no evidence to support this idea

Classification of Humans

KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES

Animal

Chordate

Mammal

Primate

Hominid

Homo

sapien

What makes us animals?

Eukaryotic

No cell walls (cell membranes)

Multicellular

Heterotrophic

What makes us chordates?

All chordates are animals with…1. Flexible “rod”called notochord along back

below nerve cord (replaced by backbone in vertebrates)

2. Dorsal, hallow nerve cord

3. Pharyngeal slits (primitive gill slits)

4. Tail at some point in life.

These are not chordates!

These ARE chordates!

What makes us mammals?

All mammals are chordates with…1. Hair or fur

2. Mammary glands – feed young milk

3. Four chambered heart

4. Internal body temperature regulation (Endothermic)

5. Lungs

Mammals

Three groups of mammals?1. Monotremes – Egg laying mammals.

Ex.) platypus

2. Marsupials – Pouched animals Ex.) Kangaroo

3. Placentals – Nutrients are passed to baby via the placenta

What makes us primates?

Mammals

Well developed brain

Binocular vision- ability to merge visual images seen from both eyes (3-D or depth)

Grasping hands and feet due to presence of 5 flexible digits and opposable thumb

Rotating shoulder joints

2 Groups Primates

Prosimians

ex) lemur

Nocturnal

Large eyes

2 Groups Primates cont.

Anthropoids

ex) monkeys, apes, humans

Day-active (diurnal)

Smaller eyes

Development color vision

This group split into two major groups when continents split

Anthropoid Branches

New World Monkeys

Found Central/South America

Tree dwellers

Prehensile tail- grasping equal to a 5th hand

Ex) spider monkey

Anthropoid Branches cont.

Old World Monkeys

Found Africa/Asia

Do NOT have prehensile tails

Ex) baboon

Anthropoid Branches cont.

Great Apes are included in the Old World Monkeys

Also called hominoids

Lack tails

Ex) gibbon, orangutan, gorilla, chimpanzee, humans

What is a hominid?

Scientists believe that 5 mya hominoid line gave rise to the earliest hominidsFamily includes humans and their closest ancestors“Humans share a common ancestor with apes”Closest relative is the chimpanzee (98% identical DNA)Thus, apes (not even the chimp) is our direct ancestor

What are Hominids?

Bipedal- walk upright on two legs

(due to locking knee joint and position of spine entry to skull)

Increased brain size

Jaw arc-shaped, no space between incisors and canines, short canines

Human Evolution-Where are We?

Primates

Prosimians Anthropoids

New World Monkeys Old World Monkeys

Hominoids

Hominids

Human and Ape Skeletal Differences

Spine shape.

Entry of spine into skull

Teeth

Brain cavity size

Feet (great toe)

Locking knee joints

Arm and leg length

Angle of femur

Pelvis shape

Charles Darwin’s Theory…

Classification of HumansHuman Chimp Pig Goldfish Jellyfish

Kingdom Animal Animal Animal Animal Animal

Phylum Chordate Chordate Chordate Chordate X

Class Mammal Mammal Mammal X X

Order Primate Primate X X X

Family Hominid X X X x

Genus Homo X X X X

Species Sapien X X X x