Final answer:
After a volcanic explosion, Genus B, which possesses a greater variety of genetic traits, is more likely to survive compared to Genus A due to higher genetic diversity. This diversity acts as a survival buffer in changing conditions, while competition for resources can also affect survival outcomes.
Step-by-step explanation:
In biology, the resilience of species after an environmental disturbance, like a volcanic explosion, relates to the concept of genetic diversity. Genus B, which contains different species with a wide variety of genetic traits, is far more likely than Genus A to survive the disaster. This is because genetic diversity within a population can provide a buffer against changes, as some species may possess traits that allow them to adapt to new conditions.
Case III suggests that populations that are not genetically differentiated are at a higher risk when their environment changes abruptly. Therefore, Genus A, characterized by a few species of similar genetic material, is at greater risk compared to the diverse species within Genus B.
Competition for resources like food and nesting space can also determine survival outcomes. If two species have overlapping needs, the one unable to compete effectively may either die off or migrate, as pointed out in scenarios mentioning competition for survival in a region.