IB Biology Option D D3 Human Evolution

1. IB Biology Option D D3 Human Evolution

2. D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K. • _____ is a naturally occurring isotope of carbon with a • half life of ________ years. • Constantly being made in the atmosphere when cosmic • rays cause ________ to fuse with _________ nuclei and • “kick out” protons Formation Decay

3. D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K. • 14C production is in equilibrium with its decay to ____ • The 14C is incorporated in _____________ which is then • taken up by _____. In the end all living things have the • same ratio of 14C to 12C • When an organism dies it no longer takes in 14C. So • over time the ratio of ____________ changes. This is • measurable and can be used to estimate age. • The limit for accurate determination of age is about • ____________

4. D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K. • ____ is an isotope with a half life of ____________ • 40K decays to ____. • When 40K is released from a volcano in _____, all of the • argon gas is driven off. So brand new rocks effectively • have a ratio 40K: 40Ar of _______ • Over time the lava may be weathered and eroded and • incorporated into _____________________. • The measured ratio of _________ can be used to date • rocks ________________ years old with an accuracy of • around __________ years

5. D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K. When to use which isotope? ____________ - K-40 - For older samples, over 100,000 years old ____________ - C-14/C-13/C-12 - For young samples, from 1000 to 100,000 years old - _____ C14 recent death; ______ C14, old!

6. D.3.2 Define half-life. Half-life = ______________________________________ _______________________________________ What is the half life for each of the isotopes represented by these curves?

7. D.3.2 Define half-life. ______ ______ ______ ______

8. D.3.4 Describe the major anatomical features that define humans as primates. human gibbon gorilla Grasping ______________ limbs

9. D.3.4 Describe the major anatomical features that define humans as primates. ________Vision

10. D.3.4 Describe the major anatomical features that define humans as primates. Monkey _________ ________ leading to reduced olfaction Monkey Squirrel vs. Doggie Human

11. D.3.4 Describe the major anatomical features that define humans as primates. Human Baboon Gorilla Generalized _________ Moo Cown

12. D.3.4 Describe the major anatomical features that define humans as primates. • Others: • Forelimbs able to ____________ • ____________ allows wide range of arm movement • (re. the above two points: if you have a gentle and patient pet dog, give it a • rub on the tummy and then move it’s forelegs, they really only move in one • plane) • ___________ reproduction • - long ____________ • - usually ______ offspring at a time • _____________ – relative to body size • _____________ – more complex, more folds • Better _____________ – more of the photoreceptors • have their own sensory neurons • ___________ dependency

13. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens.

14. D.3.5 Outline the trends illustrated by the fossils of:

15. Australopithecus afarensis • 4 – 2.5 Mya • Climate changing. Antarctic ___________advance 5 Mya • Distribution: Ethiopia, Kenya, Tanzania • Cranial capacity: ____________ cm3 • Height: 1.07m • ____________ (footprints 3.6 Mya) /climber • ______________ dental arcade but reduced canines • Arboreal / terrestrial __________

16. Australopithecus africanus(Southern Ape of Africa) • 3 – 2.25 Ma • ___________ of climate reduced rainfall • Further advance of _______________ 2.4 mya • Development of scrubland and savannah • ____________ cover retreats

17. Australopithecus africanus(Southern Ape of Africa) • Distribution: Southern and Eastern Africa • Cranial capacity: _______ cm3(Chimp = 400cm3) • __________ • 20 – 35 kg • _________ skull • _________ dental arcade • Longevity: __ years maximum • __________ of bone marrow/ brain cases • Used _____________

18. Homo habilis - the handy man • 2.4 -1.6 Ma • E. Africa • _____________significantpart of the diet • Cranial capacity: _________cm3 • Height: 1.20 – 1.35m • Simple fashioned tools – __________

19. Homo erectus – the upright man • 1.8 to 1 Mya • 0.9 Ma beginning of the Pleistocene __________ • Oscillations between ______ and ______ periods • Spread out of Africa (1.6Ma) throughout the old world • Scavenging to ________ • Use of a _____________

20. Homo erectus – the upright man • Cranial capacity: ____________cm3 (H. sapiens = 1350 cm3) • Use of _______ • Height 1.55 to 1.8m • Extended ____________ • 1st molar at ___ years old (H. sapiens = 5.9y) • Greater ___________  52 years • Speech? (______ says: yes; ________ says: no) • Improved tools: ____________

21. Homo neanderthalensis(our distant cousins?!) • 200 000 to 30 000 years ago • Europe, Middle East, into Central Asia • Evolved from __________ populations perhaps via _______________________, then became extinct • Adapted to the ________ conditions of temperate zone • ____________may have warmed cold air • The enigma of its extinction is not explained

22. Homo neanderthalensis(our distant cousins?!) • Cranial capacity: _____ cm3(H. sapiens = 1350 cm3) • ___________, long low skull • Height: 1.67m • _________ build • Improved sophisticated tools • Sometimes _______________ • Made simple _____________

23. Homo sapiens– Modern Human • From 140 000 years ago to present • Originating in _____________then went worldwide • Reached Europe about __________ years ago • _________ of the climate during the last glacial period from about 50 000ya led to their predominance over other species (e.g. H. neanderthalensis) • ____________ • _________ environment • ________________ of species, farming

24. Homo sapiens – Modern Human • Cranial capacity: _______ cm3(range 1000 to 2000 cm3) • _____ of the body’s energy consumption for _____ of body mass • __________ • __________ • Extensive tool kit including new materials (bone, ivory, antler) • ____________ thought • 1st molar tooth ___ years old • Longevity ___ years

25. Identify and label the following hominid skulls: **Skulls not to scale

26. Homo erectus Australopithecine Gorilla Modern human Neanderthal

27. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. • From the previous two slides you can see: • _______________ of the brain case • _______________ of the face • loss of _______________ • You can’t really see it but the hole in the bottom of the skull where the spinal cord exits the brain (__________ • __________) is further forward in modern humans. This distributes the weight of the head over the spine so that modern humans do not need huge necks muscles.

28. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Homo sapiens Pan troglodytes (chimpanzee)

29. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. The jaw has developed from a ___ into a ___ shape. Teeth have generally ___________ in size. (Chimpanzee provided for comparison)

30. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Human hands are adapted for ___________ and fine manipulation. In contrast gorillas have short fingers for _________________ and gibbons have elongated fingers and reduced thumbs for ________________.

31. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Skeleton, locomotion and posture • Human knees aligned under the body’s ___________ • __________ because femurs are angled __________. • Human legs _____________________ when walking. • Human spine has additional ________ to keep • centres of mass of head and trunk aligned • for bipedalism. • Big toe ______________ in humans, • which allows for an arched foot. • Ratio legs:arms __________ for • humans than other apes • Human pelvis ____________

32. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. _________, also called juvenilization or pedomorphism, is the retention, by adults in a species, of traits previously seen only in juveniles.

33. D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A.afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. • Some human characteristics thought to be a result of • Neoteny: • Lack of body hair • Small teeth and reduced • numbers of teeth • Prolonged growth period • Long life span • Flat face and thin skull bones • Lactase production • in adults • Epicanthic eye fold • Small nose • Longer trunk relative • to arms and legs

34. D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Doesn’t necessarily mean they lived together/near each other...just means _______________________________ A. afarensis & A. africanus ~ 3mya A. africanus & H. habilis ~2mya H. neanderthalensis, H. erectus, and H. sapiens ~100,000 yrs ago

35. D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Homo sapiens Homo erectus Australopithecus 1960 Up the ladder • The idea that one species smoothly evolves from one into another is regarded today as an ___________________ • Unfortunately it is a very persistent view that continually resurfaces in cartoons Public Domain Images

36. D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. A. boisei Homo sapiens Homo erectus A. robustus Homo habilis Australopithecus africanus Australopithecus afarensis “Lucy” Added 1974 1970 Branching out • The 1960s and 1970s were a fertile period for _____________ in Africa • The idea developed that ______________ __________________existed at the same time developed

37. D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Homo sapiens Homo erectus A. boisei Homo habilis A. robustus A. africanus Australopithecus afarensis 1991 Changing status As more specimens were found a clearer idea developed of the relationships between them

38. D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Homo sapiens Homo neanderthalensis Homo erectus H. heidelbergensis 1 Ma Paranthropus boisei P. robustus H. ergaster 2 Ma ? Homo rudolfensis Homo habilis A. africanus ? P. aethiopicus A. garhi 3 Ma ? ? Australopithecus afarensis 4 Ma Australopithecus anemensis ? ? Ardipithecus ramidus 2001 From a tree to a bush

39. Gorilla gorilla Pan trogolodites Homo sapiens Homo neanderthalensis Homo erectus H. heidelbergensis 1 Ma Paranthropus robustus H. ergaster Paranthropus. boisei ? Homo habilis 2 Ma Homo rudolfensis A. africanus P. aethiopicus A. garhi ? 3 Ma Australopithecus afarensis ? 4 Ma Australopithecus anemensis Ardipithecus ramidus ? ? 5 Ma ? 6 Ma Orrorin tugensis ? ? Sahelanthropus tchadensis “Toumai” 7 Ma 2003 DEEPER ROOTS

40. D.3.7 Discuss the incompleteness of the fossil record and the resulting uncertainties about human evolution. Reasons for the incompleteness of the fossil record: • fossils only form when buried under sediment before _________________ occurs; • animal bodies are usually eaten by _______________, decomposed by _________, or broken down chemically • of remains fossilized, most remain buried in __________ / remain unfound; • Measurements imprecise b/c _________________ of organisms at death (juvenile  adult)

41. D.3.7 Discuss the incompleteness of the fossil record and the resulting uncertainties about human evolution. Reasons for the incompleteness of the fossil record: • hominid fossils that have been found may or may not be ____________________ of hominid history; • hominid fossils that have been found are usually _________, and the remainder of the organism must be __________/ inferences may or may not be correct; • only _____________of individuals fossilize, leaving many questions concerning the rest of the individual’s phenotype

42. D.3.7 Discuss the incompleteness of the fossil record and the resulting uncertainties about human evolution. The large gaps in the human evolution fossil record are consistent with ______________ ____________________ The following four slides show how the gaps are filled over time with new discoveries. The graphs plot cranial size against the age of the fossil.

43. 1850 http://en.wikipedia.org/wiki/Transitional_fossil

44. 1900 http://en.wikipedia.org/wiki/Transitional_fossil

45. 1950 http://en.wikipedia.org/wiki/Transitional_fossil

46. 2002 http://en.wikipedia.org/wiki/Transitional_fossil

47. D.3.8 Discuss the correlation between the change in diet and increase in brain size during hominid evolution. • The benefits of a bigger brain include: • More ___________________ • Mastery of ______ • Cooking • Wamth • Protection • Greater_____________________ (less reliance on instinct and better able to learn and pass on knowledge necessary to adapt to an environment)

48. D.3.8 Discuss the correlation between the change in diet and increase in brain size during hominid evolution. • The cost of having a big brain: • ___________ gestation period • Years of development before • young can __________________ • Much more _________________ • occurs post birth than for any • other animal

49. D.3.8 Discuss the correlation between the change in diet and increase in brain size during hominid evolution. • In summary: • Big brains are _______________________. The mother must take in lots of energy not only during pregnancy, but for a significant time after. • Hominids needed to increase their __________________.

50. D.3.8 Discuss the correlation between the change in diet and increase in brain size during hominid evolution. The solution to this energy crisis was to swap a diet of these: http://www.flickr.com/photos/heydrienne/22080973/