Human Evolution

1. Human Evolution LESSON # 26

2. The Primates A species of mammals gave rise to the order of mammals called primates. Important Characteristics of Primates 1- Large front-facing eyes that allow for binocular vision (which enhances depth perception). 2- Limbs that have an opposable first digit, like our thumb, which makes grasping possible. 3- Tree dwelling existence.

3. The lemur of Madagascar is a modern-day descendent of the earliest primates -Large front-facing eyes -Opposable first digit -Tree dwelling existence

4. There are 60,000 species of mollusks and 750,000 species of insects. There are about 230 species of primates living today (there are 4,600 species of mammals). Ape: Any tailless primate with a humanlike appearance. Ape means a member of the family Hominidae other than humans (gorilla, chimpanzees, and orangutan).

5. Member of the Family Hominidae Chimpanzee Orangutan Gorilla Human

6. Scientific Classification of Humans

7. Common primate ancestor The common primate ancestor is unknown. It was an ape-like creature whose closest living relatives are humans, chimpanzees, gorillas and orangutans. It gave rise to both the chimpanzee family tree and the human family tree. This branching probably occurred between 6 and 7 million years ago.

8. 7 million years Common primate ancestor

9. All the species in the figure are members of the taxonomic family of Hominidae (family of man-like primates). Every member of the Hominidae family is referred to as a Hominin including human beings. Every species in this tree is extinct, except for the Homo sapiens. For perhaps 70% of the time hominins lived and died solely in Africa. The hominin fossils found outside Africa date only 1.75 Mya.

10. Australopithecus afarensisis the most famous hominin ever found. She was called “Lucy” and lived 3.18 Mya. There is no doubt that the Australopithecus afarensis species was bipedal.

11. Lucy is an Australopithecus afarensis, probably the first bipedal hominin. Lucy • -Pelvis of a biped • Long arms • Short legs • Feet that were built for grasping • - Smaller brain

12. A reconstruction of Australopithecus afarensis, a human ancestor that had developed bipedalism, but which lacked the large brain of modern humans.

13. Homo ergaster. The most dramatic changes: height of 2 meters, brain 30% larger than H. habilis (more than half of the size of modern H. sapiens brain). Homo habilis (“handy man”) is the first Homo that had tool-making abilities. A. afarensisprobably gave rise to the A. africanus (Lucy)

14. In the remarkably complete skeleton of "Turkana Boy," we can see the evolution of hominins to a form more like our own. This member of the species Homo ergaster was tall and had a much larger brain capacity than the earlier hominin "Lucy." His remains, dating from 1.6 million years ago, were found near Kenya's Lake Turkana.

15. Homo heidelbergensis gave rise to the Homo sapiens and the Homo neanderthalensis. (Lucy)

16. The Neanderthals 1- The first extinct hominins to be discovered, in 1856 in Germany’s Neander Valley. 2- It is the best known of the extinct hominins because they left many traces of themselves behind.

17. Homo neanderthalensis The H. neanderthalensis is the “caveman”. They used nothing but stone for their relatively primitive tools. They lived Europe and elsewhere in a period running from about 200,000 years ago to 27,000 years ago. H. neanderthalensis probably became extinct because they could not compete with a newer, cleverer species that had move to their territory: the Homo sapiens.

18. Neanderthal family

19. A Hominin Family Tree H. sapiens Present recent H. neanderthalensis H. heidelbergensis H. floresiensis H. mauritanicus Pleistocene 1 H. cepranensis H. erectus H. habilis P. robustus 2 K. rudolfensis P. boisei Homoergaster Au. garhi Au. africanus Paranthropusaethiopicus 3 Au. bahrelghazali Pliocene Millions of years ago Au. afarensis Kenyanthropusplatyops 4 Australopithecusanamensis Ar. ramidus 5 chimps gorillas monkeys hominins orangutans Ardipithecuskadabba Orrorintugenensis 6 Sahelanthropustchadensis ancestral primate 7

20. Homo sapiens Homo heidelbergensis Homo mauritanicus Homo ergaster Homo habilis Australopithecus africanus Australopithecus afarensis (Lucy) Australopithecus anamensis Common primate ancestor Common primate ancestor

21. Cranial capacity (the volume of the skull) has increased in hominins over time H. sapiens H. heidelbergensis H. ergaster 1400 H. habilis 1200 A. africanus 1000 A. afarensis 800 Cranial capacity (cubic centimeters) 600 400 200 4 3 2 1 Present Earliest fossil record (millions of years ago)

22. 1- We come from Africa as direct descendents of the Homo heidelbergensisspecies. 2- The first appearance of modern human beings has been dated between 100,000 and 200,000 years ago (best estimate 130,000 years ago). More scientists believe that the essence of what set modern human apart from other species is symbolic thinking.

23. Symbolic Thinking: The ability to design tools before they make them, the ability to plan for the future, the ability to represent three-dimensional animals on a two dimensional surface (art). This piece of ochre, found in South Africa, has been dated to 77,000 years ago. The researchers who discovered it believe it represents the world's oldest known work of art.