Evolution

Question 1

what is the definition of evolution?

Answer 1

1. descent w/ modification from a common ancestor
2. able to pass on heritable genetic changes to next generation
3. occurs when allele frequency changes over time

Question 2

compare characteristics of microevolution & macroevolution

Answer 2

[S]
1. due to change in allele frequency in population over successive gens

[D]
2. over shorter period of time/ longer
3. no new species formed/ new species

Question 3

explain why related species are not distributed in the same geographical region (*continental drift)

Answer 3

1. common ancestor exist before continents are separated by (atlantic ocean) due to continental drift
2. ancestral species give rise to variety of species that radiates out in this ancient supercontinent
3. when continents broke up & separate, fossilised remains were transported to where they are today
4. concept of descent with modification from a common ancestor still holds true but time & continental drift separate descendants

Question 4

why a population is the smallest unit that can evolve?

Answer 4

1. evolution: measure of change of allele frequency in a population over successive gens
2. population: grp of interbreeding indiv. of same species
3. change in allele frequency can only be measured in population over successive gens, not an indiv

Question 5

how does environmental forces act as forces of natural selection?

Answer 5

1. 2 forms exist
2. before industrialisation, majority are (A)
3. (B) arise due to spontaneous mutation
4. (A) are better camouflaged from predators due to (eg. land on light coloured lichen)
5. selective advantage as can survive
6. selected for
7. with industrialization, (lichens killed -> dark coloured)
8. (B) has been camouflage -> selective advantage
9. freq of allele coding for (B) increase
10. microevo

Question 6

what is adaptive radiation?

Answer 6

1. rapid increase in no. of specifies produced
2. from a common ancestor
3. upon introduction to new environment

Question 7

how does fossil support phylogeny & darwin theory of evolution

Answer 7

1. relics of organisms that live in the past are preserved in a rock
2. use carbon dating techniques
3. t

Question 8

what is the concept of species (biological)

Answer 8

1. definition: group of interbreeding organisms capable of producing viable, fertile offsprings
2. reproductively isolated from other species
3. share common gene pool
4. similar morphology
5. A: interbreeding to see if they produce V,F offspring
6. D: asexually reproducing organism & extinct species cannot be observed