Evolution

Question 1

3 groups of living mammals distinguished by their reproductive biology

Answer 1

• monotremes
• marsupials
• eutherians

Question 2

who are the closest living relatives of humans?

Answer 2

chimpanzees and bonobos

Question 3

who are the hominids?

Answer 3

evolutionary lineage leading to modern humans

Question 4

what is the only homonin thats not extinct?

Answer 4

homo sapiens

Question 5

a key trait that evolved in the common ancestor of hominins is:

Answer 5

bipedal locomotion

Question 6

advantages to bipedal locomotion

Answer 6

• forelimbs free to manipulate and carry objects
• eyes elevated, look for prey/ watch for predators more effectively
• move over long distances more energetically efficiently than close relatives with quadrupedal locomotion

Question 7

early hominins: Australopithecus

Answer 7

• “lucy” most complete australopith skeleton, found in Ethiopia
• had relatively small brains, elongate faces, and a bipedal gait
• 2 lines of evidence
  
  • pelvis and foot morphology
  • laetoli footprints

Question 8

homo

Answer 8

• homo clade diverged from an australopithecine ancestor

- genus homo have larger brains, less elongated faces than earlier hominin ancestors and a bipedal gait

Question 9

earliest known species of homo clade

Answer 9

homo habilis

-first evidence of tool manufacture

Question 10

habilis

Answer 10

handy man

Question 11

homo erectus

Answer 11

• large skull, relatively long legs and short and straight fingers
  
  • traits suggest they were bipedal and primarily terrestrial (not in trees)
• made more complex tools than homo habilis
• able to control fire

Question 12

who was the first hominid to leave africa?

Answer 12

homo erectus

-fossils found in europe, india, china, and indonesia

Question 13

homo neanderthalensis

Answer 13

-common ancestor had increased brain size, decreased jaw muscles
-indicating a shift in diet from herbivory to omnivory
-increased brain size may reflect increasingly complex social interactions and cultural traditions
-stocky with a large skull/brain
-advanced tool technology
hunters of large animals, cave dwelling

Question 14

who was the hominin not found in Africa?

Answer 14

• homo neandethalensis

- widespread in asia and Europe

Question 15

how do we know that neanderthalensis practiced symbolically?

Answer 15

-flower burial at Shanidar cave, Iraq

Question 16

homo sapiens

Answer 16

• evolved in Africa
• large brain, slighter build
• early humans overlapped with heir sister species neanderthalensis
• made sophisticated tools and art
  
  • paintings and sculpture
• homo spies spread across all of asia reaching north america

Question 17

did early humans and neanderthalensis interbreed?

Answer 17

• yes
• descendants of eruopeans, asians, other non africans inherited 2% of their genes from neanderthals
• genetic analysis also suggests blonde/ red hair, fair skin and thick body hair may be inherited from neanderthals

Question 18

biological evolution

Answer 18

theory that all organisms on earth are related and have changed over time from an original ancestral form

Question 19

what is modified?

Answer 19

the frequency of particular genes (alleles) within a population

Question 20

Where are genes located?

Answer 20

on chromosomes

Question 21

different versions of a gene are called

Answer 21

alleles

Question 22

the result from evolution

Answer 22

genomes of species differ from those of their ancestors

Question 23

how do populations evolve?

Answer 23

populations evolve when the environment favors some treats over others, then alleles that code for those traits increase in frequency over time

Question 24

human example of evolution

the red blood cell production in tibet

Answer 24

• tibetans who live at very high altitude, derived from chinese ancestors who lived at low altitude
• most humans respond to low oxygen at altitude by making more red blood cells to carry more oxygen
• good in short term
• tibetans have big frequency of an allele leading to production of fewer red blood cells in response to low oxygen
• results in more optimal balance of anaerobic vs aerobic metabolism in cells at high altitude

Question 25

is evolution a theory or a fact?

Answer 25

both! - theory of evolution deals with how evolution happens - its also a fact as there is a huge amount of indisputable evidence for its occurrence

Question 26

creationism and the idea of "fixed species"

Answer 26

- many believed in some form of creationism where species were created by a supernatural being - as special creations, species were considered to be fixed for all time

Question 27

fossils and cuvier

Answer 27

- george cuvier made 2 observations from his studies of fossils - younger fossils, found near surface, more similar to living species than older fossils found deeper - between layers of rock, some species disappeared, while new ones appeared

Question 28

catastrophism

Answer 28

belief that boundaries between layers correspond with catastrophes throughout time that wiped out entire species -evidence of extinction

Question 29

transmutation and lamarck

Answer 29

- jean lamarck proposed that if an animal acquired a trait during its lifetime, it could pass it to its offspring - giraffe's neck

Question 30

acquired trait

Answer 30

developed over a single lifetime

Question 31

charles darwin

Answer 31

- first to make a strong convincing argument that species change through time - ideas were influence by the - voyage on the beagle - experience with selective breeding - thomas malthus (political economist, demographer)

Question 32

voyage on the beagle

Answer 32

- noticed great variabilities with the shape of beaks among species of finches. - concluded that small changes accumulating over time were the only plausible explanation for his observations

Question 33

selective breeding

Answer 33

- enhanced desrired characteristics in future generations - a few generations of selective breeding could produce populations of pigeons that differed dramatically in appearance (artificial selection)

Question 34

thomas malthus

Answer 34

- malthu's essay on the principles of population, which discussed effects of individuals competing for limited food resources - darwin noted: species typically produce more offspring than needed- some survive and reproduce, others die without reproducing (survival of the fittest) - these observations led darwin to propose that populations of species change over time

Question 35

alfred wallace

Answer 35

- proposed a hypothesis almost identical to darwin's - both him and darwin presented a paper to linnaean society of london describing biological evolution by natural selection

Question 36

darwin theory of evolution by natural selection includes 5 observations

Answer 36

- any species, population sizes would increase exponentially if all individuals survived and reproduced successfully - populations tend to b stable in size, except for seasonal fluctuations - resources are limited (freshwater) - members of a population vary in their characteristics; no 2 are exactly the same.. - much of the variation is heritable

Question 37

darwin's inferences

Answer 37

- more individuals are produced than the environment can support - survival depends in part on inherited traits

Question 38

darwinian evolution

Answer 38

- origins of biological diversity can be explained by purely physical processes - evolutionary change occurs in groups of organisms (populations) rather than individuals - evolution is a multistage process occurring across generations - evolution occurs because some organisms perform better than others in a particular environment