Question 15
A scientist is performing an investigation using biochemistry to show the evolutionary relationship between an unknown species and four known species. She compares the DNA of the same protein found in all five species.
Her data is shown in the table.
Species Sequence
unknown ACT GCA CCC
species I ACA GCA CCG
species II ACT GGT GGA
species III ACA GCA GGG
species IV ACT GCA CCG
The scientist claims that all living organisms are related by way of common descent. The comparison of which two species BEST supports her claim?
a
the unknown species and species IV
b
species I and species III
c
species II and species IV
d
the unknown species and species II
The best comparison that supports the scientist's claim is the comparison between the unknown species and species II. Both species have the same sequence "ACT GCA" which suggests a closer evolutionary relationship. Therefore, the answer is:
d. the unknown species and species II