Hominid Evolution: How we became Human

In your opinion, what is being human? Is being human being humane? How are we different from other animals? Have we always been the same—intellectually, culturally and physically— as we are today? What other questions do you have about being human? Da Vinci sketched human development in the womb

What is the theory of evolution? In biology, evolution is the change in the heritable traits of a population over successive generations, as determined by genetic changes. In biology, evolution is the change in the heritable traits of a population over successive generations, as determined by genetic changes. Evolution is the source of the vast diversity of life: all organisms are related to each other through common descent as products of evolutionary changes over billions of years. Evolution is the source of the vast diversity of life: all organisms are related to each other through common descent as products of evolutionary changes over billions of years. Over time new species evolve from existing species and other species become extinct, resulting in the ever-changing biological world reflected in the fossil record. Over time new species evolve from existing species and other species become extinct, resulting in the ever-changing biological world reflected in the fossil record. The excavation of a dinosaur spine provides an example of how some species have become extinct over time

What is the theory of hominid evolution? Hominid (or human) evolution is the part of the theory of evolution that looks into how human beings emerged as a distinct species. Hominid (or human) evolution is the part of the theory of evolution that looks into how human beings emerged as a distinct species. The study of human evolution encompasses many scientific disciplines. Evidence comes from: The study of human evolution encompasses many scientific disciplines. Evidence comes from: Archaeology (this will be the power point’s focus) Archaeology (this will be the power point’s focus) Physical anthropology Physical anthropology Behavioral studies of modern primates Behavioral studies of modern primates Genetics and Genetics and Linguistics Linguistics

When did humans diverge from other hominids and become a separate species? 10 million years ago (m.y.a): Humans and other hominoidea (hominid-like creatures) shared common ancestors 10 million years ago (m.y.a): Humans and other hominoidea (hominid-like creatures) shared common ancestors 8 m.y.a.: Humans and other great apes shared a common ancestor 8 m.y.a.: Humans and other great apes shared a common ancestor 5 m.y.a.: Humans and chimpanzees shared a common ancestor 5 m.y.a.: Humans and chimpanzees shared a common ancestor Chimpanzees and humans are 99% genetically similar

What evidence supports hominid evolution? Fossil evidence. Examples of where fossil evidence has been found:

What evidence supports hominid evolution? The oldest hominid fossils date back 7 million years ago. Called Sahelanthropus tchadensis, 7 million year old skulls of this hominid species were discovered in Chad (Central Africa) in Sahelanthropus tchadensis skull fragments

What evidence supports hominid evolution? Between 4 million and 1 million years ago, evidence shows that the Ardipithecus and Australopithecus genuses lived in Africa. Between 4 million and 1 million years ago, evidence shows that the Ardipithecus and Australopithecus genuses lived in Africa. Australopithecines were only three to five feet tall. Their brain sizes were about 1/3 as big as modern humans’, but slightly larger than chimpanzees’ brains. Australopithecines were only three to five feet tall. Their brain sizes were about 1/3 as big as modern humans’, but slightly larger than chimpanzees’ brains. Their teeth and jaws were much larger than that of modern humans--much more similar to that of apes. Their teeth and jaws were much larger than that of modern humans--much more similar to that of apes. However, there is not enough evidence to prove that Australopithecines are the precursors to the human genus Homo. However, there is not enough evidence to prove that Australopithecines are the precursors to the human genus Homo.

Examples of evidence: 4.4 m.y.a. Ardipithecus ramidus teeth have been found in Ethiopia. 4.4 m.y.a. Ardipithecus ramidus teeth have been found in Ethiopia. The teeth appear to be more ape-like than any other hominid. The teeth appear to be more ape-like than any other hominid. Ardipithecus ramidus teeth

Examples of evidence: The most famous and complete Australopithecus specimen, nicknamed “Lucy”, was excavated in Ethiopia during the 1970s. Lucy lived 3.18 m.y.a.. Her brain size was cc… a third the size of modern humans. Lucy’s discovery revolutionized archaeology

How do we know that Australopithecines like Lucy walked upright? Lucy’s anatomy: Lucy’s anatomy: Her bowl-shaped pelvis was weight bearing Her bowl-shaped pelvis was weight bearing Her angled hip and knee joints Her angled hip and knee joints Her S-shaped vertebrae and spine Her S-shaped vertebrae and spine Her foramen magnum below her skull Her foramen magnum below her skull Her enlarged big toe, in line with her other toes Her enlarged big toe, in line with her other toes Footprints found at Laetoli, Kenya, that date to 3.7 m.y.a. Footprints found at Laetoli, Kenya, that date to 3.7 m.y.a. Model of Lucy walking upright; Lucy would have walked bent-kneed more like a chimpanzee

Examples of evidence:

Nicknamed “Mrs.. Ples” and “Taung child”, these Australopithecus africanus skulls from South Africa date back 2.5 m.y.a..

Examples of evidence: The Australopithecus (left) from Ethiopia, A. garhi, dates back 2.5 m.y.a.. Primitive stone tools just as old were found at A. garhi sites, suggesting that they may have been the first tool makers (a very human behavior…) The Australopithecus (left) from Ethiopia, A. garhi, dates back 2.5 m.y.a.. Primitive stone tools just as old were found at A. garhi sites, suggesting that they may have been the first tool makers (a very human behavior…) The other Australopithecus (right), A. boisei, nicknamed “Nutcracker Man” for his big teeth, was found in Tanzania and dates 1.75 m.y.a.. The other Australopithecus (right), A. boisei, nicknamed “Nutcracker Man” for his big teeth, was found in Tanzania and dates 1.75 m.y.a..

Who were Homo habilis? Also referred to as “Handy Man”, Homo habilis lived between 2.5 and 1 m.y.a. (overlapping with Australopithecines). Also referred to as “Handy Man”, Homo habilis lived between 2.5 and 1 m.y.a. (overlapping with Australopithecines). Their faces still looked primitive, but had less projection than Australopithecines. Their faces still looked primitive, but had less projection than Australopithecines. H. habilis’ brains were larger and more human-like than the Australopithecines. H. habilis’ brains were larger and more human-like than the Australopithecines. Archaeologists believe their larger brain size and power led H. habilis to be the first to speak - and to make and use stone tools (one of the fundamental features of modern humans). Archaeologists believe their larger brain size and power led H. habilis to be the first to speak - and to make and use stone tools (one of the fundamental features of modern humans). Their validity, however, as our direct ancestor is questioned. Their validity, however, as our direct ancestor is questioned. Homo habilis was the first member of our genus

A review of early hominid evolution: Sahelanthropus tchadensis(7.0 m.y.a.)

From the common human - chimpanzee ancestor to Homo erectus

Who were Homo Erectus? Also called upright man, Homo erectus lived between 2.5 million and 1 m.y.a.. Like us, they lived in the Neolithic Era. Also called upright man, Homo erectus lived between 2.5 million and 1 m.y.a.. Like us, they lived in the Neolithic Era. Homo erectus had larger bodies and brains than H. habilis. Physically Homo erectus had a protruding jaw, thick brow ridge and a long, low skull. Homo erectus had larger bodies and brains than H. habilis. Physically Homo erectus had a protruding jaw, thick brow ridge and a long, low skull. Homo erectus is probably our direct ancestor

What is the importance of a bigger body and brain? Homo erectus’ larger bodies required more calories, but may have helped them in self-defense against predators. Their larger brains correlate with more complex stone tools. Archaeologists suspect that their larger brains led them to develop better tools than Homo habilis or the Australopithecines; as a result Homo erectus survived longer than the other hominids. Archaeological evidence indicates that Homo erectus were the first hominids to learn to control fire.

Homo erectus were the first hominids to control fire

What can fire be used for? Fire can be used to cook meat and other foods. Cooked foods can be chewed and swallowed quickly, thus give their eaters more energy (calories). This extra energy enabled hominid brains to keep growing. Fire can be used to cook meat and other foods. Cooked foods can be chewed and swallowed quickly, thus give their eaters more energy (calories). This extra energy enabled hominid brains to keep growing. Fire can also be used to scare off predators. Animals other than humans are afraid of fire. Fire can also be used to scare off predators. Animals other than humans are afraid of fire. Hominids used fire to scare off predators

What can fire be used for? Lastly, fire can be used to keep warm in colder environments. Lastly, fire can be used to keep warm in colder environments. Homo habilis had stayed in Africa, but Homo erectus migrated to the Middle East, India, Southeastern Asia, China and Europe. Homo habilis had stayed in Africa, but Homo erectus migrated to the Middle East, India, Southeastern Asia, China and Europe. Homo erectus were the first hominids to leave Africa. Homo erectus were the first hominids to leave Africa. Homo erectus sites

Who were Homo neanderthalensis? Also known as Neanderthals, these hominids lived in Europe and Southwestern Asia/the Arabian peninsula between 200,000 and 30,000 years ago. Also known as Neanderthals, these hominids lived in Europe and Southwestern Asia/the Arabian peninsula between 200,000 and 30,000 years ago. Neanderthals are considered either a variety of Homo sapiens or a separate species. Neanderthals are considered either a variety of Homo sapiens or a separate species.

Who were Homo neanderthalensis? Physically, they stood 5’ to 5’6” tall. They were muscular and thick boned (their bones were 10-20% heavier than people’s today). Physically, they stood 5’ to 5’6” tall. They were muscular and thick boned (their bones were 10-20% heavier than people’s today). The picture shows a Neanderthal skeleton (left) next to a human skeleton (right). Notice the density of Neanderthal bones.

Where did Homo neanderthalensis live?

Who were Homo neanderthalensis? Neanderthals lived during the most recent Ice Age. To survive they lived in caves. When no caves were available they built temporary shelters from wood and animal bones. Homo neanderthalensis were skillful hunters and gatherers; they made stone blades, scrapers, and other complex tools designed for specific tasks. Caves provided Neanderthals warm shelter

Who were Homo neanderthalensis? Neanderthals attached importance to individuals’ lives and deaths. Neanderthals attached importance to individuals’ lives and deaths. For example, they had burial rituals wherein they placed flowers on their dead. They also cared for physically disabled members of their groups. For example, they had burial rituals wherein they placed flowers on their dead. They also cared for physically disabled members of their groups. Neanderthal skeletons were intentionally buried

Who were Homo neanderthalensis? Neanderthals vanished around 30,000 years ago- why remains a mystery. Archaeologists think that they either evolved in Homo sapien sapiens, or that they were replaced by our species as we spread throughout the world. A forensic reconstruction of a Neanderthal woman

What is the latest evidence about Hominid Evolution? The latest evidence found over the last decade has changed the theory by adding in new hominid species, such as: The latest evidence found over the last decade has changed the theory by adding in new hominid species, such as: Kenyanthropus platyops, or Flat Face, 3 m.y.a. Kenyanthropus platyops, or Flat Face, 3 m.y.a. Paranthropus robustus, or Robustus, 2 m.y.a. Paranthropus robustus, or Robustus, 2 m.y.a. Homo heidelbergensis, or Goliath, 800,000 y.a. Homo heidelbergensis, or Goliath, 800,000 y.a. Homo floresiensis, or Hobbit, 30,000 y.a. Homo floresiensis, or Hobbit, 30,000 y.a. The discovery of these new fossils has made us realize that there were multiple hominids alive at most times during prehistory. Only today is there just one type of hominid—Homo sapien sapiens! The discovery of these new fossils has made us realize that there were multiple hominids alive at most times during prehistory. Only today is there just one type of hominid—Homo sapien sapiens!

Who were Homo sapiens? Homo sapiens, the archaic version of our own species Homo sapien sapiens, came onto the evolutionary scene about 500,000 y.a.. Homo sapiens’ skeleton and teeth were less robust than earlier hominids; they also had large brow ridges, small foreheads and chins compared to modern humans. Their brains were much bigger than earlier hominids (sapiens= wise) Archaeologist think there is a connection between erectus and sapiens Whose skull is whose?

Who are Homo sapien sapiens? Anatomically modern Homo sapien sapiens existed by 200,000 y.a. Compared to Homo sapiens, our own species developed a more advanced culture including clothing, jewelry and art in addition to tools. Our large brain size, our imagination, our abstract thinking, our tool making and our art mark us as human!

What achievements make Homo sapiens human? By 35,000 y.a. humans made cave paintings around the world. Archaelogists have three theories why: Magical significance Pictorial textbook designed to help young hunters Children’s initiation rite into adulthood

Cave painting from (clockwise): Australia, Algeria and Argentina

So… what does it mean to be human? Activity: Spend a few minutes reviewing your notes. Then answer the question above: Activity: Spend a few minutes reviewing your notes. Then answer the question above: From a scientist or historian’s perspective;and From a scientist or historian’s perspective;and From your own perspective. From your own perspective. After you have done so, form a group with two other students. After you have done so, form a group with two other students. Your job is to make a cave painting as a group that expresses visually what it means to be human, based on all of your ideas. Your job is to make a cave painting as a group that expresses visually what it means to be human, based on all of your ideas.