Explain how variation and natural selection may have led to the evolution of the woolly mammoth from the steppe mammoth.
A frozen woolly mammoth that was $43\,000$ years old was discovered in Siberia. Its DNA was removed and sequenced. The sequences of the genes for the $\alpha$ and $\beta$ chains of haemoglobin were then compared with those of modern Asian elephants. The findings indicated that, compared with Asian elephants: • only one amino acid differed in the woolly mammoth’s $\alpha$ chains • three amino acids differed in the woolly mammoth’s $\beta$ chains. Explain the likely effect of these differences on a molecule of mammoth haemoglobin.
Suggest why it is useful for Arctic mammals to have haemoglobin whose affinity for oxygen is affected only slightly by temperature changes.
Explain whether or not Fig. 2.1 gives evidence that woolly mammoth haemoglobin is better adapted to a cold climate than Asian elephant haemoglobin.
Explain whether or not Fig. 2.1 gives evidence that woolly mammoth haemoglobin is better adapted to a cold climate than Asian elephant haemoglobin.