Final answer:
For a population to be in Hardy-Weinberg equilibrium, it must meet specific conditions, including no mutations, no gene flow, large population size, random mating, and no natural selection. The correct option is a.
Step-by-step explanation:
When discussing the Hardy-Weinberg equilibrium, we must consider certain conditions that must be met for a population of crocodiles to truly be at equilibrium. According to the Hardy-Weinberg principle, the conditions include:
- No mutation occurring in the DNA sequence.
- No migration, meaning new individuals must not migrate into the population.
- The population size has to be very large to discount genetic drift.
- Random mating must occur, meaning individuals pair by chance, not according to their genotypes.
- And importantly, there must be no natural selection; allele frequencies must not change due to survival or reproductive advantages.
To answer the student's question, for a population of crocodiles to be in Hardy-Weinberg equilibrium, the first condition, 'No new mutations have occurred,' must be true. This means we expect no evolutionary changes due to genetic alterations. The correct option is a.