Scientists wanted molecular data in order to establish the evolutionary relationships of New Zealand’s Myosotis species. They extracted DNA from individuals of Myosotis species collected from three different islands in New Zealand. Before DNA sequencing, the samples were used in a polymerase chain reaction: primers, deoxynucleotides and Taq polymerase were added, and the mixture was subjected to 35 cycles of treatment. Each cycle included one minute at $95^\circ\text{C}$, then one minute at $50^\circ\text{C}$, followed by four minutes at $72^\circ\text{C}$. Describe what happened to the DNA at each temperature.
Fig. 5.1 shows the three largest New Zealand islands. DNA sequence data from three Myosotis species were compared. The findings are set out in the bullet points. Explain the results shown for the three Myosotis species.
State two factors, apart from natural selection, that could cause genetic change in populations of Myosotis.