Cambridge Pre-U Syllabus - Cambridge International Examinations

26
2.3 The evolution of life
Content
Selection and changes in allele frequency
Speciation
Aspects of evolution
Cambridge Pre-U Draft
Learning outcomes
Candidates should be able to:
a) outline Darwin’s and Wallace’s observations and conclusions
b) describe evolutionary patterns of divergence and adaptive radiation including the Galapagos finches as
an example
c) outline the mechanisms leading to evolutionary changes in allele frequency in populations including: the
role of mutation in producing genetic variation; how such variations might enable organisms with
particular alleles and particular phenotypes to survive better and reproduce more frequently
d) describe and explain directional, stabilising and disruptive selection
e) discuss what effect increased environmental stress resulting from global climate change (with increased
temperatures and more extreme weather conditions) might have on habitats and organisms and thus on
food chains and niche occupation
f) compare current and background rates of extinction with those during past mass extinctions (students
should be aware that these figures are not agreed by all scientists)
g) explain the role of isolation in allopatric speciation (with particular reference to evidence from ‘ring
species’) and sympatric speciation (in relation to behavioural isolation in African cichlids)
h) explain the causes and effects of bacterial genetic resistance to antibiotics
Practical learning outcomes
Candidates should be able to:
i) investigate the relationship between aspects of the environment and features of species such as banded
snails (Cepaea spp.)