Modern humans ( Homo sapiens ) are the result of at least 62 million years of primate evolution .
We a relatively new species, apparently emerging in Africa sometime within the last 200,000-100,000 years.
We are the only hominid (upright walking primate) species alive today.
Our first primate ancestors were likely small, shrew-like tree-dwelling animals.
Eventually primates became larger and more sophisticated, to the point where monkeys and apes appear (35 and 25 million years ago, respectively).
Hominids (upright walking primates), our closest ancestors, likely appear sometime between 10-6 million years ago.
Plesiadapiforms - The First Primates?
Aegyptopithecus - An Early African Monkey
Living Non-Human Primates
In the past there were a great many more types of primates in existence.
Today there are only 250 species world wide, and most of these are endangered.
They are most threatened by habitat loss (in most cases due to human actions), hunting , and disease .
Living Non-Human Primates 2
Today’s primates are very diverse.
They range in size from tiny 2 ounce mouse lemurs to 450 lbs male gorillas.
They occur naturally in Africa , large sections of Asia , South America , Mexico , and one small area of Europe.
Many primates are vegetarians, others omnivores, and one is entirely carnivorous.
Living Non-Human Primates 3
Some are nocturnal, while most are diurnal.
Some are relatively unintelligent, while others are some of the smartest animals on the planet (next to us).
Most ape and some monkey species make and use tools.
Some Principle Primate Features
Grasping hands (and sometimes tails).
High degree of learned behavior.
Large brains (in relation to body size and when compared to other animals).
Most have flat nails in stead of claws.
Almost all live in social groups.
(Relatively) long life-spans.
Living Primate Groups
Lorises (Africa and Asia)
Tarsiers (Southeast Asia)
Monkeys (Africa, Asia, Americas)
Apes (Africa and Asia)
Humans (All over the damn place)
Male Mountain Gorilla
Red Ruffed Lemur
Cotton Top Tamarin
Genetic evidence suggest that hominids arise in Africa perhaps as early as 10 million years ago.
The earliest fully documented hominid fossils date to only 4.4 million years ago.
This species has been named Ardipithecus Ramidus .
Though a biped, this species is still very ape-like in many ways.
Ardipithecus Ramidus Remains and Reconstruction
Hominid Evolution 2
By 4.2 million years ago a series of species known as australopithecines begin to appear.
The most famous of these is an example of the species Australopithecus afarensis , which has been nicknamed “ Lucy .”
Though less primitive than earlier hominid species, Lucy an her kind are still quite apelike in many ways.
At this point in hominid evolution, brain size is still roughly that of a modern chimpanzee.
The Genus Homo
The genus “homo,” which eventually gives rise to modern humans first appears around 2.5 million years ago.
The first of these species, Homo habilis , is the first hominid who has be shown to have made stone tools .
By 1.8 million years ago Homo Erectus appears.
Homo erectus may be the first hominid to have left Africa .
The Genus Homo 2
H. erectus has body proportions similar to that of modern humans.
The most intelligent hominid so far.
May have hunted large game.
May have used fire.
May have had at least some language abilities.
Archaic Homo Sapiens
By out 800,000 years ago a series of hominids appear in various parts of the world that have features associated with both H. erectus as well as later hominids.
The hominids may or may not be direct ancestors to modern humans.
They do, however, appear to have given rise to Neanderthals.
Neanderthals first appear around 150,000 years ago and die out around 27,000 years ago
They are a cold-weather adapted species found mostly in Ice-Age Europe and parts of the Middle East .
Anatomically they are know for their robust muscular bodies and unusual facial anatomy.
Most likely the most intelligent hominid other than modern humans.
Neanderthal and Modern Human
Ginger Neanderthals? Gingerthals)
Homo sapiens first appear in Africa between 200,000 and 100,000 years ago.
Most likely evolved out of either Archaic Homo sapiens or Homo erectus .
The main difference between Homo sapiens and their hominid ancestors is their extreme intelligence - Homo sapiens are by far the smartest hominid that ever lived.
Homo Sapiens 2
By around 12,000 years ago modern humans have migrated world-wide, living in just about every environment except Antarctica, extremely high mountain regions, and isolated oceanic islands.
It has been hypothesized modern humans out competed other hominid species to quickly emerge as the only surviving hominid species on the planet.
Homo Sapiens Dispersal
Race and Ethnicity Part 2
Homo sapiens is a very young species.
Though we feature much diversity in appearance, these differences are minor compared to our biological similarities.
In fact, all human beings are quite closely related.
We are all likely only 2000 or so generations removed from a common African ancestor .
Many of our physical differences (skin, color, hair color, etc.) are relatively recent adaptations to local environment conditions .
Fast-acting evolutionary forces such as genetic drift have also played a role in our creating such variation as well.
In the past biologists and anthropologists classified humans into different groups based on physical characteristics.
Modern genetics has revealed that these categories make very little sense biologically.
Most biologists and anthropologist no longer view these categories as scientifically valid.
Biological Classification 2
Biologists (generally) use the term “subspecies” to classify populations within a species that have become so different from the species as a whole that they are on the verge of becoming new species.
The term “race” has traditionally been used by scientists as the equivalent of the subspecies concept when classifying humans.
Biological Classification 3
Modern genetics has shown that humans are far too closely related for any division into subspecies to be valid.
The term race, therefore, no longer has any significant scientific meaning.
In fact, there is greater biological diversity within traditional racial categories than between them .
Biological Classification 4
Today when the term “race” is used what is actually being referred to are largely cultural, not biological differences .
In other words, cultural and biological traits are being confused .
Ethnicity - A group of people sharing a common origins, history, language, and in many cases religion, social and political structure, and perceived biological commonalities. (Ethnicity can be defined both from within and without a group.)
Ethnicity refers primarily to culture not biology.
Ethnocentrism - … is the belief that one’s own patterns of behavior [and belief] are always natural, good, beautiful and important, and that strangers, to the extent that they live [and think] differently, live by savage, inhuman, disgusting, or irrational standards. – Marvin Harris (1995)
Ethnocentrism - the belief that one’s own cultural group and the behavioral patterns in which it engages are simply the way humans should be and the further a group or individual deviates from these norms the more “wrong” (strange, weird, unnatural, immoral, unacceptable) they are.
Anthropology and Society
Before the advent of modern genetic studies, anthropologists actively engaged in the study of race and disseminated views that turned out to be inaccurate to the general public.
In large part because of these efforts false ideas still permeate the public discourse cause a great deal of confusion in regards to the differences between human biology and human culture.