1.1. Ailuropoda melanoleuca, the giant panda, and Ailurus fulgens, the red panda, are both native to China. The following evolutionary evidence suggests that these two panda species are closely related.

• They live in similar environments;

• They both digest bamboo as a primary source of food;

• They both have a pseudo-thumb (a sixth digit) used to grip and shred food such as bamboo.

Table 1 shows the differences between a comparable sequence of mitochondrial DNA of four different mammals. 

Table 1

A group of students concluded that the raccoon is most closely related to the black bear. Use Table 1 to evaluate this conclusion. 

1.2. The base sequences of a different section of mitochondrial DNA (not those shown in Table 1) were analysed and the number of differences was counted between the giant panda DNA and the DNA of the other mammals, as shown in Table 2. 

Table 2

Mitochondrial DNA is estimated to mutate 1.87 x 10^-7 mutations site^-1 yr^-1. Use the data from Table 2 to calculate how long ago the giant panda and the red panda evolved from a common ancestor. Give your answer in standard form and to three significant figures. 

1.3. The red panda has 36 chromosomes per somatic cell whereas the giant panda has 42 chromosomes. Offspring born when these two species mate are infertile. Suggest why. 

1.4. Explain how genome sequencing can be used to deduce evolutionary relationships between organisms, such as the giant panda and red panda.