Question

A student is comparing traits for five related bird species. They make a chart and record data for four different traits. They then use the chart to make a cladogram showing their hypothesized relationships between the species.

	1	2	3	4	5
Head Size	20 cm	20 cm	20 cm	20 cm	20 cm
Beak Color	Black	Blue	Blue	Black	Black
Eye Color	Black	Black	Red	Red	Red
Eye Number	2	2	2	2	3

What occurred at point C on the cladogram?
A. Head size increased.
B. Red eyes developed.
C. The beak color of the common ancestor of Species 4 and 5 changed from blue to black.
D. The descendants of Species 3 diverged to become Species 4 and Species 5.

Answer 1

Hint:-A cladogram is a diagram used to display relations between species in cladistics. However a cladogram is not an evolutionary tree since it does not demonstrate how descendants are bound to ancestors, nor does it show how much they have evolved, meaning that se

Complete Answer:-A cladogram uses lines that branch out into a clade, a group of species with a last common ancestor, in various directions. Cladograms have several forms, but they all have lines that branch out from other lines. It is possible to follow the lines back to where they branch out. These branching off points represent a hypothetical ancestor (not an individual entity) that can be inferred from the above to show the characteristics shared between the terminal taxa. This hypothetical ancestor could then include clues regarding the order of evolution of different traits, adaptation, and other ancestor evolutionary narratives.


In the figure given above, the other features at point C do not change other than the beak colour that changes from Blue to Black. Therefore the right answer is option C, i.e “The beak colour of the common ancestor of Species 4 and 5 changed from blue to black”.

Note:- The DNA and RNA sequencing data and computational phylogenetics are now very widely used in the generation of cladograms, either on their own or in conjunction with morphology, whereas historically such cladograms were mostly created based on morphological characters.