Final answer:
The Provisional Hypothesis of Pangenesis by Darwin included the theory of 'gemmules' which was deemed incorrect after Mendel's work, which established the chromosomal basis of inheritance.
Step-by-step explanation:
The Provisional Hypothesis of Pangenesis, proposed by Charles Darwin, is a theory that attempted to explain how characteristics are passed from parents to offspring. This hypothesis, which predates Mendel's work on genetics, has three main parts: firstly, it suggests that organisms possess particles called gemmules that control hereditary traits; secondly, it posits that these gemmules are collected from all parts of the organism and are responsible for transmitting inherited traits to the next generation; thirdly, Darwin theorized that gemmules could be modified over time, potentially through environmental influences, and these modifications could be passed to progeny, contributing to evolution.
Darwin's hypothesis eventually fell out of favor because it was replaced by the more accurate Mendelian inheritance, which is based on Gregor Mendel's work. Mendel demonstrated that genes are inherited in a predictable manner, following specific ratios and patterns - called the chromosomal basis of inheritance. This Mendelian principle elucidates how traits are passed on through dominant and recessive alleles, refuting the idea of gemmules. Today, our understanding of inheritance and the fundamentals of genetics continues to evolve, integrating both Mendelian and non-Mendelian patterns of inheritance within the vast and interwoven web of life's evolutionary history.