Lecture 10 - Case study - human evolution

Question 1

what are the 6 stages of studying human evolution?

Answer 1

1) temporal framework
2) reconstructing paleogeography
3) reconstructing environment
4) evidence from living organisms
5) evidence from fossil organisms
6) evidence from archaeology

Question 2

when is is thought the start of human evolution was?

Answer 2

7 million years ago when the chimp-human split occurred

top of miocene just before pliocene on geological column

Question 3

why have we gotta a much better understanding of humans than dinosaurs?

Answer 3

much more recent so can use a variety of dating methods - accuracy of dating is getting better with time

Question 4

how else is the fact that human evolution was relatively recent useful?

Answer 4

better knowledge of geology stratigraphy - the rocks still exist - therefore can subdivide the 7 million years much better

Question 5

what is an added complication when studying human evolution?

Answer 5

glacial events - sea levels changing - temps changing - unstable environments
- need to understand where we are in the glacial cycles to understand human evolution

Question 6

when were sea levels last lowest?

Answer 6

last glacial maximum - 18,000 yrs ago

Question 7

when were sea levels at their highest?

Answer 7

middle miocene 14ma - before humans split from chimps (greenhouse world)

Question 8

what are rainfall patterns effected by?

Answer 8

by which part of the glacial cycle the worl is in

Question 9

what are the study of pollen cores in the East African rift lakes useful for?

Answer 9

• they can give you a chronology of the dramatic environmental changes as humans were evolving and what effects they have

Question 10

how can you date sediments by drilling cores in the ocean crust?

Answer 10

study oxygen or boron isotopes from forams (single celled organisms that live in the ocean with a carbonate shell - so remain in ocean floor for years)

Question 11

what can fine details about oxygen isotopes reflect?

Answer 11

how much ice was at the poles and therefore sea temperatures

Question 12

what does boron show?

Answer 12

how much co2 was in the atmosphere and how acidic the ocean was

Question 13

how can we get evidence from living organisms to help study human evolution?

Answer 13

1) look at nearest living relatives e.g. chimps
- look at their history, anatomy, genomics, physiology and behaviour
2) look at other human societies that havent advanced as much e.g. sandbush people in south Africa (still practice hunter-gatherer societies)

Question 14

describe the human fossil record

Answer 14

• terrible fossil record - few terrestrial deposits
• human skulls are very delicate - mostly find teeth and body bones with cranium smashed too pieces
• get some footprints

Question 15

what evidence can you find from archaeology?

Answer 15

• tools (very robust)
• charcoal (work out when fire was invented)
• find burials (instantly fossilises the bodies)

Question 16

what are the 4 groups that 200 extant species of primates are classified into?

Answer 16

1) promisians (lemurs, lorises, bushbabies)
2) new world monkeys (spider monkeys, marmosetts)
3) old world monkeys (baboons , colobus monkeys)
4) hominoids (apes, includins humans (hominins - new term))

Question 17

what are anthropoids?

Answer 17

collectively the monkeys and apes

Question 18

when did primates appear in the fossil record?

Answer 18

85ma

Question 19

when was the KT mass extinction?

Answer 19

65ma

Question 20

what happened in terms of primate evolution 50ma?

Answer 20

• primates of modern aspect appear
• adaptive radiation of primates
• anthropoids evolve din Africa

Question 21

when did hominoids appear in Africa?

Answer 21

20ma

Question 22

when did hominoids migrate into Asia as Asia/Africa collide?

Answer 22

18ma - adaptive radiation of hominoids in Asia

Question 23

what happened 10ma in terms of primate evolution?

Answer 23

as asian hominoid migrates back to Africa and is ancestral to all later hominoids (including hominins)

Question 24

when was the earliest hominoid?

Answer 24

proconsul - 22ma from Africa

Question 25

there is debate over whether lemurs+lorises or tarsiers are more derived - what now solves alot of theses issues?

Answer 25

molecular studies - solve issues that used to be decided by morphological studies

Question 26

over the history of research into human origins, human remains discovered in caves were often interpreted, depending on where they were found, as either .....

Answer 26

- soldiers from the horde of gengis khan The | - remains of Cossacks that had died on the way back from their victory over Napoleon

Question 27

what is it now know that the fossils found in caves actually are?

Answer 27

remains of Neanderthals, Cromagnon Man etc

Question 28

what significant book was published in 1859?

Answer 28

Darwins - origin of species - evolution became accepted

Question 29

what book did huxley publish in 1863?

Answer 29

“Evidence as to man’s place in nature”. Based on comparative anatomy and embryology he concludes that humans share a close evolutionary relationship with great apes (particularly African apes)

Question 30

what did darwin publish in 1871?

Answer 30

“Descent of man”. He concurs that humans are most closely related to African apes and suggests that humans originated in Africa

Question 31

describe Dubois discovery 'java man'

Answer 31

java man (homo erectus) - huge animal, heavily muscled, thick skull etc

Question 32

what was the issue with dubois discovery?

Answer 32

people thought the java man was just ape fossils - this annoyed dubois so he locked the fossils away never to be seen again

Question 33

describe the piltdown man (1908-1913)

Answer 33

- supposed discovery of a human ancestor from England - people started to forget that humans evolved just in Africa and actually evolved everywhere

Question 34

what discovery was made in 1925?

Answer 34

``` Taung boy (australopithecus africanus 3.5-2.5ma) - found in south africa at the end of the rift valley - very small with small brain - he was neglected by the rest of the world ```

Question 35

what discover was made in 1927?

Answer 35

peking man - homo erectus (0.4-0.7ma) - very big so was brushed to one side and thought to be more on the ape side - fossil destroyed in world war however more similar ones have been found from the same area

Question 36

what did Robert Broom continue today between 1925-1935?

Answer 36

continued his search in johannesburg despite Tuang boy being neglected and fins more fossils such as A.africanus(3.5-2.5ma) and A.robustus (2.0-1.0ma)

Question 37

what is the difference between africanus and robustus?

Answer 37

robustus has a much thicker jaw

Question 38

what happened in 1953 regarding the piltdown man?

Answer 38

was accepted as a hoax - had set back human evolution for 50 years - Brooms discoveries were started to be taken more seriously and people started to search more in Africa