How does speciation occur?
A barrier separates the original population into two groups. Due to the different environmental conditions (selection pressures) either side of the barrier, different alleles are selected that better adapt them to their specific environment. The gene flow between the two groups are interrupted causing the mutations within the populations to be contained and hence two new species are evolved.
HB
Related Biology A Level answers
All answers ▸Explain how smooth muscle in the arterioles can reduce blood flow.
The black mamba’s toxin kills prey by preventing their breathing. It does this by inhibiting the enzyme acetylcholinesterase at neuromuscular junctions. Use your knowledge of muscle contraction to explain how this prevents breathing.
What is meant by the "fluid-mosaic" model of cell membrane structure?
What is meant by the phrase saltatory conduction?