Chapter 32-3Chapter 32-3

Primates and HumanPrimates and Human

OriginsOrigins

Carolus Linnaeus named our order Carolus Linnaeus named our order Primates, which means __ In Latin?Primates, which means __ In Latin?

What is a Primate?What is a Primate?

All Primates have:All Primates have:

Binocular visionBinocular vision

Well-Developed CerebrumWell-Developed Cerebrum

Relatively long fingers and toesRelatively long fingers and toes

Arms that can rotate around their shoulder Arms that can rotate around their shoulder jointsjoints

Binocular VisionBinocular Vision

Is the ability to merge Is the ability to merge visual images from both visual images from both eyes, thereby providing eyes, thereby providing depth perception and a depth perception and a three-dimensional view of three-dimensional view of the world.the world.

Many primates have a flat Many primates have a flat face, so both eyes face face, so both eyes face forward with overlapping forward with overlapping fields of view.fields of view.

Well-Developed CerebrumWell-Developed CerebrumThe large and intricate cerebrum The large and intricate cerebrum of primates – including a well-of primates – including a well-developed cerebral cortex – developed cerebral cortex – enables them to display more enables them to display more complex behaviors than many complex behaviors than many other mammals.other mammals.

Many primate species have Many primate species have elaborate social behaviors that elaborate social behaviors that include adoption of orphans and include adoption of orphans and even warfare between rival even warfare between rival primate troops.primate troops.

Fingers and ToesFingers and ToesPrimates normally have five flexible Primates normally have five flexible fingers that can curl around objects, fingers that can curl around objects, most also have flexible toes. most also have flexible toes.

These flexible digits enable many These flexible digits enable many primates to run along tree limbs and primates to run along tree limbs and swing from branch to branch with swing from branch to branch with ease.ease.

In most primates the thumb and the In most primates the thumb and the big toe can move against the other big toe can move against the other digits (called an opposable thumb), digits (called an opposable thumb), this adaptation allows many primates this adaptation allows many primates to hold objects firmly in their hands or to hold objects firmly in their hands or feet.feet.

ShouldersShoulders

Primates are well Primates are well adapted to climbing adapted to climbing because they can rotate because they can rotate in broad circles around in broad circles around a strong shoulder joint.a strong shoulder joint.

Evolution of PrimatesEvolution of PrimatesIt is hypothesized that humans It is hypothesized that humans and other primates evolved and other primates evolved from a common ancestor that from a common ancestor that lived more than 65 million lived more than 65 million years ago.years ago.

Primates that evolved from Primates that evolved from two of the earliest branches two of the earliest branches look very little like typical look very little like typical monkeys and are called monkeys and are called prosimians (lemurs, tarsiers, prosimians (lemurs, tarsiers, lorises, and bush babies)lorises, and bush babies)

1.) Prosimians1.) ProsimiansMost prosimians alive today Most prosimians alive today are small, nocturnal are small, nocturnal primates with large eyes primates with large eyes that are adapted to seeing that are adapted to seeing in the dark. Many have in the dark. Many have doglike snouts.doglike snouts.

Examples (living today):Examples (living today):

Bush babies of Africa,Bush babies of Africa,

Lemurs of MadagascarLemurs of Madagascar

Lorises and Tarsiers of AsiaLorises and Tarsiers of Asia

2.) Anthropoids2.) AnthropoidsMembers of the primate group that Members of the primate group that includes monkeys, apes, and includes monkeys, apes, and humans.humans.This group split very early into two This group split very early into two major branches.major branches.One branch, found today in Central One branch, found today in Central and South America, is called the and South America, is called the New World monkeysNew World monkeys Ex: spider and Ex: spider and squirrel monkeyssquirrel monkeysThese monkeys have long, flexible These monkeys have long, flexible arms that enable them to swing from arms that enable them to swing from branch to branch.branch to branch.They also have a They also have a prehensile tailprehensile tail, , which is a tail that can coil tightly which is a tail that can coil tightly enough around a branch to serve as enough around a branch to serve as a “fifth hand”.a “fifth hand”.

2.) Anthropoids continued2.) Anthropoids continuedThe other anthropoid group, The other anthropoid group, which evolved in Africa and Asia, which evolved in Africa and Asia, includes the Old World Monkeys includes the Old World Monkeys and the Great Apes.and the Great Apes.Old world monkeys, such as Old world monkeys, such as langurs and macaques, spend langurs and macaques, spend time in trees but lack prehensile time in trees but lack prehensile tails.tails.Great apes, also called Great apes, also called hominoidshominoids, include gibbons, , include gibbons, orangutans, gorillas, orangutans, gorillas, chimpanzees, and humans.chimpanzees, and humans.

Hominid EvolutionHominid EvolutionBetween 6 and 7 million years ago, Between 6 and 7 million years ago, the hominoid line gave rise to a the hominoid line gave rise to a branch that ultimately let to the branch that ultimately let to the ancestors and closest relatives of ancestors and closest relatives of modern humans, the hominid family.modern humans, the hominid family.The hominids displayed several The hominids displayed several distinct evolutionary trends. Over distinct evolutionary trends. Over millions of years, they became able millions of years, they became able to walk upright and developed to walk upright and developed opposable thumbs, and large brains.opposable thumbs, and large brains.The skull, neck, spinal column, The skull, neck, spinal column, hipbones, and leg bones of early hipbones, and leg bones of early hominid species changed shape in hominid species changed shape in ways that enabled later species to be ways that enabled later species to be bipedalbipedal, walk upright, this freed both , walk upright, this freed both hands to use tools.hands to use tools.

Early HominidsEarly Hominids

At present, most paleontologists agree that the At present, most paleontologists agree that the hominid fossil record includes at least these hominid fossil record includes at least these genera: genera: Ardipithecus, Australopithecus, Ardipithecus, Australopithecus, Paranthropus, Kenyanthropus, and Homo (as Paranthropus, Kenyanthropus, and Homo (as many as 20 separate species. many as 20 separate species.

This diverse group of hominid fossils covers This diverse group of hominid fossils covers roughly 6 million years. All these species are roughly 6 million years. All these species are relatives of modern humans, but not all of them relatives of modern humans, but not all of them are human ancestors. are human ancestors.

AustralopithecusAustralopithecus

Early group of hominids, lived from about Early group of hominids, lived from about 4 million to 1 million years ago. 4 million to 1 million years ago.

They were bipedal apes that spent at least They were bipedal apes that spent at least some time in trees.some time in trees.

Structure of their teeth suggest a diet rich Structure of their teeth suggest a diet rich in fruit.in fruit.

Small brainsSmall brains

LucyLucy

ParanthropusParanthropus

Grew to the size of well-fed linebackers.Grew to the size of well-fed linebackers.

Huge, grinding back teeth.Huge, grinding back teeth.

Diet probably included coarse and fibrous Diet probably included coarse and fibrous plant foods.plant foods.

All died out.All died out.

Kenyanthropus and Kenyanthropus and SahelanthropusSahelanthropus

Kenyanthropus skull was discovered in Kenya Kenyanthropus skull was discovered in Kenya by Meave Leakey in 2001.by Meave Leakey in 2001.Ear structure resembled those of chimpanzees, Ear structure resembled those of chimpanzees, and its brain was rather small.and its brain was rather small.Existed at the same time as the A. afarensis.Existed at the same time as the A. afarensis.Sahelanthropus skull was found in 2002 in West Sahelanthropus skull was found in 2002 in West Africa.Africa.Brain size of a modern chimp, yet it has a short, Brain size of a modern chimp, yet it has a short, flat face more like that of a human.flat face more like that of a human.Lived about 7 million years ago, there is debate Lived about 7 million years ago, there is debate about whether it is a hominid or not.about whether it is a hominid or not.

Genus Genus HomoHomo

Homo habilis “handy man” lived about 2.5 Homo habilis “handy man” lived about 2.5 million years ago, used stone and bone million years ago, used stone and bone tools.tools.Homo ergaster had a larger brain and Homo ergaster had a larger brain and downward-facing nostrils lived about 2 downward-facing nostrils lived about 2 million years ago.million years ago.Homo erectus lived from .2 to 1.8 million Homo erectus lived from .2 to 1.8 million years ago, migrated out of Africa and years ago, migrated out of Africa and through the middle east into china.through the middle east into china.

Migration PatternsMigration Patterns

The Road To Modern HumansThe Road To Modern HumansHomo neanderthalsis – named after the Homo neanderthalsis – named after the Neander Valley in Germany where their Neander Valley in Germany where their remains were found. Made stone tools and remains were found. Made stone tools and lived in organized social groups. Lived 200,000 lived in organized social groups. Lived 200,000 to 30,000 years ago.to 30,000 years ago.Homo sapiens – Lived 100,000 years ago to Homo sapiens – Lived 100,000 years ago to present. Sometime around 40 – 50 thousand present. Sometime around 40 – 50 thousand years ago they began using new technology to years ago they began using new technology to make more sophisticated tools and changed make more sophisticated tools and changed their way of life. One group of Homo sapiens their way of life. One group of Homo sapiens called Cro-Magnons lived in Europe about called Cro-Magnons lived in Europe about 40,000 years ago and are thought to be the 40,000 years ago and are thought to be the ancestors of modern humans.ancestors of modern humans.