Final answer:
Species are susceptible to new mutations, which may lead to the emergence of new viruses like H5N1, increased by factors such as high-density farming and environmental changes. Evolution based on genetic variation facilitates the spread and survival of pathogens, as seen with antibiotic-resistant bacteria.
Step-by-step explanation:
Species may indeed be susceptible to new mutations and due to such genetic changes, it may be inevitable that a new virus will arise. For example, the avian influenza virus H5N1, with a high fatality rate, could cause another human pandemic. This possibility increases with high-density farming and incursions into wilderness areas, which provide more opportunities for viruses to jump from animals to humans. Similarly, deforestation has been linked to an increase in populations of malaria vectors, such as the mosquito Anopheles darlingi. Moreover, the overuse of antibiotics has led to the emergence of antibiotic-resistant bacteria, showcasing how evolutionary pressures can facilitate the spread of dangerous pathogens. Evolution operates on pre-existing genetic variations, and as these variations become advantageous under certain conditions, they can lead to the rise of traits in a population that enable the survival and spread of a species or a strain.