Final answer:
Darwin's "descent with modification" is a fundamental principle of evolutionary biology that describes how species change over time through natural selection acting on inherited traits, leading to the adaptation and diversification of species.
Step-by-step explanation:
Charles Darwin's concept of "descent with modification" refers to the process by which organisms change over time due to natural selection acting on heritable variations among individuals. This theory posits that species evolve as organisms with traits that confer a survival advantage are more likely to reproduce, thereby passing those traits on to future generations. Over time, this can lead to the development of new species. In his book On the Origin of Species, Darwin explained this process in depth, using evidence from the fossil record and observations from his journey aboard the HMS Beagle.
Darwin and Alfred Russel Wallace independently conceived the mechanism of evolution by natural selection, presenting their ideas to the Linnaean Society in 1858. Darwin's subsequent publication provided considerable detail on the process, which was further supported by the eventual understanding of genetics, thanks to Gregor Mendel's work on inheritance. Darwin posited that all life, including humans, is related through common descent and that natural selection is the primary mechanism for adaptive evolution.