evolution and biodiversity

Question 1

when do they think that the first eukaryotes formed

Answer 1

2.7 million years ago

Question 2

when did the cambrian explosion occur

Answer 2

500 million years ago

Question 3

what happened during the cambrian explosion

Answer 3

• life moves onto land (pangaea supercontinent)
• consume O2 and released CO2
• mass loss of plants = formed fossil fuels

Question 4

when was the Permian-Triassic extinction event

Answer 4

252 million years ago

Question 5

what happened during the permian triassic extinction event

Answer 5

• metor, volcanism, methane release, high CO2 = reduced marine & vertebrate

dinosaurs developed from surviving species

Question 6

when was the cretaceous-paleogene extinction event

Answer 6

65 million years ago

Question 7

what happened during the cretaceous-paleogene extinction event

Answer 7

asteroid hit = forces vapourised rock, blocked sunlight for years, acid rain, lots of fires
- 75% species extinct - including dino
- species that evolved are similar to those we know now

Question 8

events in human development (evolutionary)

Answer 8

bipedalism
increased brain size
lengthened gestation and infancy

Question 9

what are the 3 main phases in human development (evolutionary)

Answer 9

1. early (hominid) phase
   - ape like
2. Australopithecine phase
   - widespread in Africa, still apelike
3. Human (Homo) phase
   - current human anatomy

Question 10

how do we know that early humans spread from africa

Answer 10

1. genetic mtDNA - maternally inherited (most variation in africa)
2. linguistics (more diverse in africa)
3. climate change at the time (favoured migration from africa)

Question 11

what is Linnaeus taxonomy

Answer 11

binomial nomenclature and system of classification
- grouped according to relatedness
DKPCOFGS

Question 12

does the genetic change occur first or does the environmental change?

Answer 12

the random genetic change first,
then the environmental challenge causes selection based on those changes

Question 13

evidence of evolution

Answer 13

1. palaeontology
2. biogeography
3. compare anatomy/ embryo development
4. biochemistry

Question 14

how does palaeontology provide evidence of evolution

Answer 14

• fossil records (although these are rare)

Question 15

how are fossils formed

Answer 15

1. die -> buried quicky (prevent decomposition)
2. conditions available for fossilisation
3. found or exposed so that we can then collect the fossil

Question 16

how does biogeography provide evidence of evolution

Answer 16

• continental drift allows us to compare between continents (large scale)
• geographical barriers allow us to compare on small scale (speciation)

Question 17

how can comparing anatomy/embryo development provide evidence for evolution

Answer 17

• similar features indicative of common ancestor

anatomical vestiges = whale pelivs, appendix, coccyx, goose bumps

Question 18

how can biochemistry provide evidence for evolution

Answer 18

• common chemicals
• DNA homology = comparing DNA sequences, pseudogene
• ERV - mapping common origins from viral infection tags that are in DNA locus

Question 19

examples of recent microevolutions

Answer 19

1. mosquito resistance to DTT
2. antibiotic resistance
3. Viral evolution

Question 20

how is evolution relevant to biomedical science

Answer 20

understanding diseases
- negative changes from mutations
mismatch hypothesis
- our DNA different to our lifestyles of the modern day
developing drugs
- plants

Question 21

impact on health research if reduction of biodiversity

Answer 21

reduced biodiversity = less plant species
- natural medicines derived from plants lost
or less available to discover

Question 22

what are model organism

Answer 22

non human species used in scientific research to understand biological processes, with the expectation that discoveries will be applicable to other organisms including humans