Answer: D. allopatric; breakdown
Explanation:
Allopatric speciation is a type of speciation whereby individuals of the same biological population becomes separated up to the extent that there will no longer be gene flow between them.
The correct answer is - No.
The Cambrian explosion is a term used for the big and rapid diversification of the animal species, but it is not the period in which the animal life started. The animal life started in the period between 620 and 550 million years ago, in what is known as the Vendian Period. In the Vendian Period, the first complex animal organisms appeared, started to develop and evolve, though it is not a period where there was a high diversification of the species. The later Cambrian Period provided better living conditions, and that resulted in a so called ''explosion of life'', which resulted in much more new species developing and evolving.
An example of ATMOSPHERE affecting the BIOSPHERE. Atmosphere because it is AIR pollution and biosphere because it causes LUNG TISSUE damage.
Resident 1 is to give the most valid results.