The story of primate evolution.

How is it that we went from…

Primate Evolution Humans, apes, monkeys, and lemurs belong to a group of mammals called primates. Although we are all diverse, we share similar traits.

Primate Evolution We have high levels of manual dexterity, which is the ability to manipulate or grasp objects with our hands. In addition to keen eyesight and long, movable arms, we also have larger brains than most animals.

Primate Evolution Primates are distinguished by their flexible hands and feet. All primates have five digits on each hand and foot. Humans have fingers and toes. Primates have opposable first digits – thumb or toe.

Primate Evolution Primates and humans alike depend more on vision than we do our sense of smell. Our eyes are protected by a bony eye socket and are mounted on the front of our faces creating binocular vision or overlapping fields of vision.

Primate Evolution Primates also have flexible bodies, especially limber shoulders and hips which allow them to rely upon their hind limbs for locomotion. With the exception of humans, primates continue to walk on all fours when on the ground. They can however walk upright for short distances.

Primate Evolution Due to brain size and function, primates have better problem-solving capabilities as well as unique social behaviors. Primates have complex rules within their social groups that coincide with established communication.

Experimentation in body language 101.

Primate Evolution Unlike most animals, primates tend to have fewer offspring. Most have one offspring at a time – sometimes two. Either way their pregnancies are long and the offspring usually have to depend on the mother much longer than other animals.

Old World Monkeys vs. New World Monkeys

Old World Monkeys Old world monkeys live throughout Africa and Asia. They are diurnal (active during the day), tend to live on the ground, and live in social groups.

Colobus Monkey

Macaque - Japan

Baboons.

Primate Evolution New world monkeys tend to inhabit tropical rain forests and live within the trees. They do not have fingernails nor opposable thumbs. They are all distinguishable because of their prehensile tail, which functions like another thumb.

Spider Monkey.

Tamarin

Primate Evolution Apes are in a different category than monkeys. They are the smallest remaining species of primates.

Primate Evolution Apes generally have larger brains in proportion to their body size. They have longer arms than legs, barrel-shaped chests, no tails, and flexible wrists. They are often highly social and have complex forms of communication.

Primate Evolution Apes are divided into two smaller groups: Lesser Apes: Gibbons and Siamangs. Great Apes: Orangutans, gorillas, chimpanzees, and humans!

Primate Evolution Lesser apes are arboreal gymnasts of the ape family meaning they prefer to chill in the trees swinging from branch to branch as needed. They can easily walk about on the ground, but they prefer not to.

Primate Evolution Great apes are studied individually as orangutans, gorillas, chimpanzees, and humans are quite unique in their own ways.

Primate Evolution Orangutans are the largest arboreal primate that lives in Asia and Asia alone. The males become so large that they tend to prefer being on the ground. Females give birth once every 8 years and will nurse their offspring for at least six years.

Primate Evolution Gorillas are the largest of the primates. They prefer being on the ground where they walk on all fours supporting themselves on their knuckles. Those that live in the wild have been known to create basic tools out of sticks and those in captivity have been known to use sign language.

Primate Evolution Chimpanzees are also knuckle-walkers and have well-developed communication skills. They are more like humans in their physical structure and behavior.

Primate Evolution Humans are classified in a separate subcategory of hominids called hominins. Hominins are humanlike primates that appear to be more closely related to present-day humans than other apes. Humans are the only existing species of hominins that are still alive today.

The Rise of Man

The fossil transition from early anthropoid to ape is not clear. Somewhere in the midst of everything is the missing link – that one fossil that will make the connection between man and ape.

The Rise of Man Hominoids: include all non-monkey anthropoids including the living and extinct gibbons, orangutans, chimpanzees, gorillas, and humans. The earliest known hominoid fossil dates back 25 million years ago.

The Rise of Man Due to a lack of fossils, scientists have also turned to DNA testing of living hominoid species. Chimpanzees share 96% of their DNA sequences with humans making us the closest two living relatives within the hominoids.

The Rise of Man Hominoids are the largest of the primates with the largest brains compared to body size. They tend to have broad pelvises, long fingers, no tails, and flexible arm and shoulder joints. They tend to have either an upright or semi-upright posture with less specialized teeth.

The Rise of Man Fossil records show that some 23 million years ago there could have been at least 100 different hominoid species. They would have migrated from Africa and Asia to other parts of the world.

The Rise of Man About 8 million years ago, the ancestors of man split off from the ancestors of apes. Hominin fossils prove that these skeletal remains are more human than they are chimpanzee.

The Rise of Man Hominin Characteristics: Larger brains than hominoids. Thinner/flatter faces. Smaller teeth. Lengthened thumbs and more flexible wrists. Bipedal – able to walk upright on two legs.

The Rise of Man As hominins began to walk upright they developed a stronger stance, shorter arms, restructured pelvic bones, and a change in its head position in relation to its spine. In humans, the spine attaches at the base of the skull. In all other animals in connects at the back of the skull.

The Rise of Man To walk or not to walk – which is better? Those who walked were more obvious to predators. Standing up takes more energy and takes a greater toll on the body than being on all fours.

The Rise of Man By walking upright, man would be able to travel further and faster. They could see food more easily from where they stood. Standing upright also protected a greater part of them from the sun. It is easier to carry thing standing up.

The Rise of Man What lead mankind to walk? We have no idea. We don’t know when we started walking; we don’t know why we started walking. We simply began to walk.

Lucy Lucy was one of the most popular and well known of the fossil discoveries. She was believed to live somewhere between 2.9 and 4 million years ago.

The Rise of Man Lucy was the size of a chimpanzee with somewhat long arms, curved fingers, but had hip and knee joints that resembled those of humans. Lucy was the first fossil record that proved mankind was bipedal.

The Rise of Man Those who fell under the Genus Homo arrived somewhere around 2.5 to 3 millions years ago. Homo species had bigger brains, lighter skeletons, flatter faces, and smaller teach than their ancestors. Homo species are the first to have learned to use fire and modify stones to make tools.

The Rise of Man Homo habilis – “handy man” This species lived in Africa somewhere between 1.4 and 2.4 million years ago. Homo habilis was not the only Homo species to live during this time.

The Rise of Man As the Homo genus continued to evolve and multiple, they began to scavenge and hunt throughout their territories. Homo floresiensis – the Hobbit was discovered in 2004 and believe to be one of the youngest of our ancestors. The Hobbit was no more than a meter tall but had adapted stone tools.

The Rise of Man Homo neanderthalensis – also known as the Neanderthal or caveman roamed the earth about 200,000 years ago. They were short but muscular. It is believed that they existed during one of the many ice ages which explains why they figured out how to use fire and build primitive shelters.

The Rise of Man Scientists have discovered both Neanderthal and human fossils in the same locations throughout parts of Europe leading them to believe both lived together. However, DNA testing proved that each was a separate and unique species that may not have been directly related.

The Rise of Man Homo sapiens – humans as we know it – are more slender than their Homo counterparts. They have thinner skeletons, rounder skulls, and smaller faces with prominent chins. The first fossil records indicate that Homo sapiens were around 195,000 years ago.

The Rise of Man Homo sapiens appear to have had the ability to use a range of resources and environments At some point they opted to migrate beyond Africa, but why?

The Rise of Man The world’s population was much different than today’s. the world was much different than today’s as well. The Out-of-Africa hypothesis states that mankind evolved in Africa and only Africa – later migrating to other realms of the world.

The Rise of Man The earliest civilizations begin to appear throughout the world roughly 40,000 years ago. Mankind began to develop sophisticated tools and weapons including spears and bows. They began to fish, wear tailored clothing, and domesticate animals.

The Rise of Man Cro-Magnons – the first man – represent the beginning of now historic hunter-gatherer societies. Humans continued to spread throughout the world. They began to travel by both land and sea reaching the far corners of the earth – adapting to new challenges and establishing new civilizations well beyond the reach of others. It was the dawning of mankind as we know it.