| Date | May 2013 | Marks available | 2 | Reference code | 13M.3.HL.TZ1.2 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Outline | Question number | 2 | Adapted from | N/A |
Question
Outline how isolation of a gene pool can lead to evolution.
Markscheme
a. initially isolated populations may have been genetically different/different allele frequencies;
b. different mutations in two gene pools;
c. different parts of population subject to different selective pressures / OWTTE;
d. over time leads to changes in allele/gene frequencies;
e. may lead to reproductive isolation;
Examiners report
Although this was a popular option, candidates did not do very well on it.
Candidates struggled to outline how isolation of a gene pool can lead to evolution. Very vague responses were seen with seldom any reference to different selective pressures on the isolated populations.
