Chapter 16 Primate to Human Evolution

Ardipithecus ramidus

"Ardi" Discovered in 1994 Ethiopia. Lived 4.4 million years ago. Is the most ape like hominid fossil. Is an incomplete fossil (missing pelvis, knee, foot bones. Meaning it is inconclusive if Ardi was bipedal, but it is generally assumed he was)

Australopithecus afarensis

"Lucy". An early australopithecine from East Africa that had a brain size equivalent to a modern chimpanzee's (also had chimpanzee characteristics such as a low forehead, flat nose, and no chin) and is thought to be a direct human ancestor. She had human like teeth and stood (bipedal) about 4 ft tall. She is the most complete skeleton of Australopithecus afarensis.

Austrlopithecus

"Southern Ape"

Homo habilis (handy man)

2 million years ago; first to make tools/weapons, made stone tools for cutting, scraping, and chopping. Had larger brains that previous hominids (1/2 the size of modern day humans). First to exhibit a form of simple speech.

What is a primate?

A group of mammals that includes lemurs, monkeys, apes, and humans that share common traits.

Homo sapiens "wise man" neanderthalensis

A species of the creatures Hominid who have larger brains (roughly the size of modern humans brains) and to which humans belong, dependent of language (evidence of language is the hyoid bone) and usage of tools. They had thick bones and large faces with prominent noses. They buried their dead which suggests some sort of religion.

The science of studying the fossils of humans is_______. A. Paleoanthropology B. Geology C. Paleontology D. Anthropology

A. Paleoanthropology

This type of organism evolved from prosimians ancestor some 50 million years ago. It's name means "human like."

Anthropoid

Hominids

Apes lack tails and have different adaptations for arboreal life. Long muscled forelimbs for climbing and swinging and knuckle walking. Gibbons, Orangutans, African Apes, and humans

Hominids

Are bipedal primates

The earliest primates were most like ______. A. Homo sapiens sapiens B. Lemurs C. Squirrels D. Rats

B. Lemurs

What primates are native to South America? A. Old World monkeys B. New World monkeys C. Apes D. Strepsirrhines

B. New-World Monkeys

The first Homo sapiens were _____. A: Cro-Magnon people B: Homo erectus C: Australopithecus afarensis D: Neanderthals

B: Homo erectus

What characteristics are common to all primates? What are the major functions of all of these characteristics?

Binocular Vision (allows for good depth perception), Opposable Thumbs (lets you grasp things and swing) , and Flexible Joints (allows you to bend and use your arms more effectively, and swing from trees).

This is the ability to focus both eyes in overlapping fields. It gives depth perception.

Binocular vision

If you see an organisms walking on two legs instead of four you could use this word to describe it.

Bipedal

the study of the fossil lucy helped scientists determine that

Bipedalism evolved before a large brain. Since Australopithecus afarensis had strucutes that indicated bipedalism and a brain of ape-like volume.

Which of the following pairs of terms is most closely related? A. Primate—Squirrel B. Arboreal—Gorilla C. Strepsirrhine—Hominid D. Cro-Magnon—Homo sapiens

D. Cro-Magnon—Homo sapiens

Paranthropus boisei and P. Robustus

Early hominid with powerful jaws and thick heavy bones. Not direct ancestors of humans. Family tree extinct 100 million years ago.

Homo erectus (upright man)

First to use fire as a tool (this allowed them to stay warm, cook food, be productive after the sun goes down, and fend of predators safely). They also lived in caves which tells us they were an evolution that started to be less nomadic than others. They war animal skins, and closely resemble modern day humans. They also had a larger brain in comparison to Homo habilis (handy-man).

Compare a skeleton of a gorilla and a human

Gorilla - C-Shaped Spine -Spinal cord exits near the back of the skill (magnum foramen) *this makes the head hang slightly forward and not sit directly on the spine. Ex. When a gorilla pounds its chest it's head is then not looking forward it is looking backwards slightly. -Arms longer than legs-used in walking -Pelvis is long and narrow Modern Human -S-Shaped spine -Spinal cord exits at bottom of skull *skull sits directly on the spine -Arms shorter than legs not used for walking -Pelvis is bowl shaped to aid in standing

These are the most humanlike of all the anthropoids.

Hominids

Anthropoids (Human-Like)

Includes New World monkeys from Central and South America, Old World monkeys from Africa and Asia, gibbons from southeast Asia, and the Hominidae or great apes—orangutans, gorillas, chimpanzees, and humans.

Why was the development of bipedalism important to the evolution of hominids?

It increased speed, and walking on two legs leaves the arms and hands free for other activities, such as protections and feeding young and using tools. Therefore, being bipedal greatly increase the survivability of these primates on the ground.

Characteristics of Primates

Large brains in comparison to body size. Most are arboreal. Flexible shoulders and hips. Opposable thumbs. Binocular vision. Color vision for depth perception and to detect fresh fruit.

Australopithecus africanus

Live 2-3 millions years ago and had some ape-like features. Possibly evolved from afarensis (Lucy).

Homo sapien cro-magnon

Lived about 35,000-40,000 years ago. They spread throughout Europe and are identical to modern humans in height, skull structure, tooth structure, brain size (with capacity for speech). They were also toolmakers and artist (cave paintings).

Strepsirhines

OLDEST OF ALL. Small primates with large eyes and are nocturnal. Live in tropical forests of Africa and Southeast Asia. Lemurs, aye-ayes, Lorises, Pottos, and Galagos.

Compare "Old World" and "New World" monkeys

Old world monkeys - larger than new world - younger fossils - live in Europe, Asia, and Africa - both terrestrial and arboreal - do not have prehensile tails New World Monkeys - smaller than old world - older fossils - arboreal - live in central and South America - have prehensile tails

This is the body part that is like another hand. Some organisms would find it hard to move through the trees in the forest without it. It is a common trait of most New World monkeys.

Prehensile Tail

This is the group of mammals that includes all monkeys, apes, and even humans.

Primates

This organism may have evolved from an early primate. It is small and monkey like and has big eyes that look right at you. It could be a lemur or a tarsier.

Prosimians

Haplorhines

Tarsiers. Not much has changes except for size in 45 million years.

Australopithecus anamensis

The oldest species of australopithecine from East Africa and a likely ancestor to australopithicen afarensis (Lucy). Lived about 4 million years ago, lived in lakeside forest, large teeth, small ear openings, and was bipedal.

How could you tell from the position of the foramen magnum that an animal walked upright? Explain.

These differences in position reflect the difference in habitual body posture. In upright bipedal humans the head rests atop the vertebral column which helps to balance the mass of the head above the vertebrae. In prograde (organisms with bodies more parallel to the ground like gorillas) the head protects anterior of the vertebral column, and thus the foramen magnum is positioned and oriented posteriorly. ( https://carta.anthropogeny.org/moca/topics/foramen-magnum-placement )

Magnum foramen

opening in the base of the skull through which the spinal cord is continuous with the brain

This adaptation of primates allows grasping and swinging

opposable thumb

Two major groups of primates

strepsirrhines and haplorhines