Discuss the use of cladograms in phylogenetic studies.

a. a cladogram is a diagram which shows shared characteristics/phylogenetic relationships;
b. phylogeny is the study of evolutionary origins/ancestry;
c. clade is a group of (all) organisms that evolved from a common ancestor;
d. evidence from biomolecules/DNA/RNA/protein/cytochromes;
e. cladograms can be compared with other representations of phylogenetic relationships/may confirm fossil/anatomical evidence;
f. organisms placed close together in a cladogram are closely related evolutionarily;
g. there may be more than one possible cladogram (for a particular group) raising questions about evolutionary relationships;
h. divisions between clades/nodes suggest the sequence in which groups diverged;
i. cladograms can be used to estimate time since groups diverged;
j. cladograms are often similar to classification based on other evidence/traditional methods;
k. cladograms may lead/have led to reclassification of a group;

Although this was a popular option, candidates did not do very well on it.

While some candidates had an idea that cladograms were used to show evolutionary relationships, they were not able to clearly indicate what clades were and how cladograms were used. Some candidates confused cladograms with dichotomous identification keys. Candidates seldom received more than 3 out of 6 marks for this question.