Hominidae is family containing great apes and humans

1. Hominidae is family containing great apes and humans

2. Species that had many similarities to humans, and that were in the genera Australopithecus and Homo have gone extinct. Homo sapiens is the only species that survives today of these two genera.

3. Oldest fossil species of these two genera is Australopithecus afarensis, from about 3.7 mya in the Africa

4. For the next 1-2 million years, our relatives lived in eastern and southern Africa in savannas

5. The first fossil species of the genus Homo is Homo habilis. This species made simple stone tools which may have been used in butchering animals and to cut vegetation.

6. 2.0 mya Homo erectus evolved H. erectus was taller (5-6') than H. habilis, had a larger brain, and developed more advanced tools.

7. Did H. erectus use fire? Fire could be used to hunt game, for protection against predators and to cook toxic chemicals out of plant foods. Possibly the use of fire allowed H. erectus to move into other habitat types in Africa.

8. Check out movie, Quest for Fire

9. Over the next 1.4 my, H. erectus engaged in migrations within and out of Africa

10. Populations that evolved in sub-Saharan Africa would have to cross the Sahara, perhaps during interglacial periods

11. After interglacial periods a landbridge connecting Africa and Eurasia, the Arabian peninsula, allowed H. erectus to move into Europe and Asia, about 800,000 years ago H. erectus populations were well-distributed in Asia and Europe by 500,000 years ago

12. Many anthropologists believe H. sapiens evolved from H. erectus in Africa about 300,000 years ago, again in savannas These early men and women had heavier bones than today, thicker skulls, and brow ridges, i.e. they are archaic H. sapiens but still H. sapiens, with brains as big as modern humans. Then, H. sapiens replaced H. erectus populations throughout world.

13. Neanderthals (H. sapiens)—lived in Europe, Middle East, and Asia, 130,000 to 35,000 years ago Neanderthals used tools and had burial rituals Both Neanderthals and modern humans evolved from archaic H. sapiens

14. Hypotheses as to where modern Homo sapiens came from Modern H.s. evolved several times from groups of archaic H.s. in Europe, Asia, and Africa. H.s. evolved one time in Africa. Archaic H.s., Neanderthals included, were evolutionary dead ends.

15. Biochemists today try to recover DNA samples from fossilized skulls of Neanderthals to compare with DNA of living humans, to see whether Neanderthals contributed genes to modern pops

16. Work published Nov. 2006 DNA came from leg bone of male Neanderthal Suggests Neanderthals and modern humans diverged from a common ancestor between 370,000 and 500,000 years ago Suggests Neanderthals and modern humans did not interbreed (much?)

17. H. sapiens then followed the path of H. erectus into the Sahara and across the Arabian peninsula into Europe and Asia.

18. By 100,000 years ago H. sapiens moved out of Africa and started replacing H. erectus across its range.

19. How was H. erectus replaced? Interbreeding? Losing in competition for resources to H. sapiens?

20. From 75,000 to 50,000, glaciers were at a maximum around the world. 50,000 years ago there was a brief interglacial and it is at this time that first fossils of H. sapiens are found in Europe.

21. It is hypothesized that H. sapiens' development of projectile weapons and group hunting techniques allowed them to take relatively large game, like mammoths, whose bones could be used for tools and to construct shelters.

22. Theory of “creative explosion” Modern human behavior didn’t really take off until Homo sapiens was in Europe 40,000 years ago

23. Modern human behavior Refined tool-making from bones, art, symbols on tools.

24. Creative explosion hypothesis may be a result of a biased sampling of archaeological sites, i.e., many sites in Europe were explored while few in Africa received the same level of attention.

25. Recent finds from Blombos Cave in South Africa Bone tools, some with etching on them that suggest the use of symbols, a behavior thought to be linked to abstract thought and speech. Bone tools were likely awls for working leather, others were weapons, probably spear points. The finds are about 70,000 years old and show that the inhabitants of the cave ate antelope and fish

26. 40,000 to 50,000 years ago humans were up to the limits of the ice sheets in Europe and Asia. 25,000-18,000 years ago, much of northern regions was glaciated and sea level was relatively low so that Beringia formed

27. Shortly before 25,000 ya humans first invaded Alaska, perhaps following the species they hunted. Even though colonists made it into Alaska, they may have been prevented from moving further south by glaciers that would have lasted until about 16,000 years ago. When glaciers receded, colonists moved south and eventually spread throughout North and South America.

28. It's possible that some earlier movements occurred, if, for example, ice-free areas existed along the Pacific coast, or in the interior. However, colonization of North and South America before about 15,000 years ago is debatable.

29. The range expansion of humans throughout North and South America in 15,000 years is one of the most rapid and extensive range expansions of which we have evidence.

30. What allowed the Homo species to expand their range so quickly? Their ability to live in and modify their environment, e.g. The use of tools and fire. For example, they started building shelters.

31. Colonization by humans of oceanic islands was taking place concurrently with some of the events of above

32. Some of the islands were not islands at points in the past. For example, colonization of the Sunda region of Asia was a result of landbridges available 75,000 years ago at a time of glaciation.

33. Wallacea (Sunda) was probably relatively easily colonized because the many islands were close to each over--i.e. less than 40 miles apart.

34. New Guinea may have been reached 70,000 years ago and then colonization of Australia and Tasmania could have occurred, again partly when landbridges were present.

35. Islands relatively close to Sahul like the Bismarcks were colonized by about 32,000 but more distant islands were not colonized till fairly recently (last 4000 years), when Polynesians had developed navigational abilities.

36. IImportant features in the evolution of population leading to H. sapiens Evolution of erect stance--hands are free for other activities Enlargement of brain Evolution of long period or parental care,, providing us with the basis of culture—accumulated knowledge, customs transmitted over generations. Complex language

37. Culture is what makes human unique species, allows us to pass on knowledge which allows us to manipulate environments to meet our needs

38. 3 stages of human culture Scavenging/gathering/hunting Scavenging from other animals was probably important part of getting food for early humans. Only in the last 50,000 (maybe 70,000?) years has toolmaking become sophisticated enough that hunting could make significant contribution to diet.

39. 3 stages of human culture Agriculture-developed in Eurasia and Americas 10-15,000 years ago Earliest was slash and burn As people settled down, populations became bigger. As agriculture became more efficient, some people could specialize in other activities (technology, industry, and the arts)

40. 3 stages of human culture Machine age—Industrial revolution, means we have a greater need for fuel, death rates have declined, so that our population is growing.

41. In terms of organic evolution, we probably haven’t changed that much from our ancestors of 10,000 years ago.

42. Culturally, we have changed, much faster than organically For example, 100 years ago, no one drove cars--today everyone does. This is a change in behavior caused by cultural, rather than organic evolution.

43. One consequence of our cultural evolution is our impact on species invasions

44. Species invasions and biotic homogenization Introductions of non-native species have become more and more prevalent over time with the increasing ease with which humans traverse the globe In historical times, many of the invasions have been a result of settlers in a new area wanting to bring familiar plants and animals with them

45. Most commonly introduced mammals include • rabbits • domestic cats • several species of rats • house mice • domestic pigs • domestic cattle • domestic goats • domestic dogs

46. Most commonly introduced birds include • waterfowl species • gallinaceous birds (chickens, pheasants, etc.) • pigeons • parrots

47. Geographic patterns of introductions Palearctic region has largest number of bird and mammal introductions and has the largest area Australia has a large number of introductions as well, despite its relatively small size Oceanic islands have been the hardest hit with 60% of all bird and mammal introductions

48. Patterns with non-native plant introductions are similar Islands often have a substantial part of their biotas composed of non-native species. New Zealand has approximately 1790 native plant species and 1570 exotics. Hawaii has 1150 native plant species and 850 exotics.

49. Aquatic systems also affected—In Arizona, 67 of 95 breeding fish species, 71%, are non-native

50. Much of the biota of isolated oceanic islands is endemic, found nowhere else, making their displacement by exotics particularly harmful to global biodiversity.