Final answer:
The susceptibility of organisms to environmental change through evolution is not entirely random due to the non-random process of natural selection and other mechanisms like gene flow and sexual reproduction. While mutations are random, their survival and proliferation are influenced by how well they help organisms adapt to their environments, which is determined by natural selection.
Step-by-step explanation:
The question 'Is susceptibility to environmental change "evolutionarily random"?' pertains to the nature of evolution and the mechanisms behind it.
While the process of mutation, which introduces genetic variations, is indeed random, the overall process of evolution is not entirely random due to natural selection and other mechanisms such as gene flow and sexual reproduction. Mutations themselves do not determine whether an organism will be better suited to its environment. However, the non-random process of natural selection does affect which mutations will be advantageous or disadvantageous based on environmental conditions. For example, in a changed environment, certain individuals with particular phenotypes, which are better adapted, may reproduce more successfully than others, leading to changes in genetic frequencies within a population. Hence, evolution responds to a changing environment, but it is not a process that is entirely random or without a pattern.
Furthermore, phenomena such as migration and sexual reproduction, which affect evolution, are not random. Events like gene flow through migration or recombination of genes during sexual reproduction can influence which genetic variations become more widespread in a population. These processes contribute to the non-random nature of evolutionary changes over time.