CHAPTER 26.3 PRIMATE EVOLUTION

SC.912.L.15.10 Identify basic trends in hominid evolution from early ancestors six million years ago to modern humans, including brain size, jaw size, language, and manufacture of tools.

CIRCLE MAP

What do I know about primates?

WHAT IS A PRIMATE?

Mammal with relatively long fingers and toes.

Nails instead of claws.

Arms that can rotate around shoulder joints.

A strong clavicle(collar bone), binocular vision (both eyes used together).

Well developed cerebrum (largest portion of the brain-the “thinking” part).

SKELETAL FEATURES OF PRIMATES

How are the skeletal features of your hands different from external features of the paws of a dog or the hooves of a horse?

SKELETAL FEATURES OF PRIMATES

Primates are bipedal, or capable of walking on 2 limbs.

What is an advantage of being bipedal?

Having binocular vision? (paper)

TREE MAP- INSIDE COMPOSITIONS

PRIMATES

Prosimians

Hominoids

As we learn today…

Write some characteristics about the 3 groups of primates.

Fill in the missing information.

EVOLUTION OF PRIMATES 1) Prosimians:

Oldest living primate group

Most are small and active at night-nocturnal

i.e. lemurs, lorises, and tarsiers

Tarsiers are known as “living fossils” because their phenotypes have changed since their appearance in the fossil record 40 mya.

EVOLUTION OF PRIMATES 2) Anthropoids:

Humanlike primates

i.e. New World monkeys and Old World monkeys

New World: squirrel and spider monkeys

Old World: spend time in trees but no prehensile tail.

Prehensile tail: “fifth hand”

EVOLUTION OF PRIMATES 3) Hominoids:

Lesser apes

i.e. gibbons, orangutans, chimps, gorillas, humans

Walk upright, long lower limbs, opposable thumbs

HOMININE EVOLUTION The hominoids in the line led to humans

called hominines.

i.e. modern humans

Evolved to walk upright, walk on two legs (bipedal), grasping thumbs, and large brains.

MODERN HUMANS Homo neanderthalensis:

arose 200,000 ya.

Lived in complex social groups, controlled use of fires, and excellent hunters.

Lived in Europe until 28,000 to 24,000 ya.

MODERN HUMANS Homo sapiens:

Arrived in Middle East from Africa 100,000 ya.

50,000 ya began using stone blades for tools.

Arrived in M.E., they found H. neanderthalensis already there. Coexisted for several thousand years. (no one knows what happened to them)

H. sapiens: only surviving member of the diverse hominine clade.

SKULL EVOLUTION What changes can you see?

Why do you think this happened?

DOUBLE BUBBLE-AS CLOSING Complete a double bubble to compare human and

gorilla skeleton. Connect the terms you learned today into your

map.

H. sapiens

H. neanderthalen

sis