Final answer:
Scientists used flies for genetic experiments after Mendel to take advantage of their short generation times, large number of offspring, and observable traits. Mendel's work with pea plants, which were true-breeding and fast-growing, established the foundational laws of inheritance.
Step-by-step explanation:
Scientists conducted experiments using flies instead of pea plants after Mendel because flies, like the fruit fly Drosophila melanogaster, also have clear genetic traits that can be observed. Flies have a short generation time and produce large numbers of offspring, making it easier to conduct genetic studies and observe inheritance patterns. Additionally, by the time scientists began working with flies, they could work with microscopy techniques and breeding setups that were not available during Mendel's time.
Mendel's initial work with pea plants laid the groundwork for genetic research because he selected a species that was easy to manage, reproduced quickly, and had observable traits that followed particular inheritance patterns. His choice of garden pea, Pisum sativum, was due to their true-breeding nature and the ease with which he could control their pollination. This allowed Mendel to produce statistically significant results and establish the foundation for the laws of inheritance.