Evolution

Question 1

Advantages of Molecular Methods (just 3 will suffice)

Answer 1

1. Avoids the pitfalls of convergent evolution when morphological evidence could be due to convergence
2. Quantifiable and can be converted to numerical form and open to statistical analysis
3. Unambiguous and objective. A, T, C, G are easily recognised and hence is not dependent on subjective judgements or observations involving qualitative differences
4. Homologous regions of DNA of different species provides many points of comparisons as each nucleotide position is a point of comparison
5. Nucleotide data can be used to trace evolutionary relationships of species that
   are so different that there is little morphological homology
6. Nucleotide data can be used to assess phylogenetic relationships that cannot
   be measured by comparative anatomy and other non-molecular methods

Question 2

Importance of maintaining biodiversity

Answer 2

1. Protect food chains
2. Maintain rich reservoir for biomedicines
3. For ecotourism
4. For science
5. Maintain genetic diversity for food

Question 3

How different [species] evolved on different islands

(dependent on context, this answer may not be applied to other qns if context is different. just know the gist of it will suffice)

Answer 3

1. There is variation in the subpopulation on each island
2. Founder effect occurs when some members of [species] colonised other islands
3. The subpopulations were exposed to different ecological niches, and hence, subjected to different selection pressures.
4. Since there is variation within the subpopulation, individuals with favourable characteristics are selected for and survives to maturity, reproduce and pass down their favourable alleles to their offsprings.
5. Over time, gene pool of subpopulation becomes significantly distinct from the ancestral population
6. The subpopulations become geographically isolated leading to allopatric speciation
7. Subpopulations did not interbreed, hence, gene flow was disrupted
8. Over succesive generations, evolution of different species occurred, leading to adaptive radiation

Question 4

Explain difference between classification and phylogeny

Answer 4

1. Classification is the organisation of species based on their shared characteristics while phylogeny is the organisation of species to show their evolutionary relationships
2. Phylogeny takes into account evolutionary relationships while classification does not