Final answer:
Evolution is studied through methods such as examining fossil records, analyzing DNA evidence, and conducting longitudinal studies like the Grants' work on Galapagos finches which showed natural selection in action.
Step-by-step explanation:
Evolution is studied using various scientific methods, including fossil records, DNA evidence, and case studies. Charles Darwin's study of Galapagos finches is a classic example of how living species such as finches and tortoises can provide insights into natural selection.
In Darwin's observations, he noted that each finch species was adapted to its specific environment, with distinct beak shapes suited for different types of food available on the islands. After Darwin, the Grants' research on finches further demonstrated how beak sizes could evolve in response to environmental changes, such as shifts in food availability due to climate anomalies like El Niño events.
In addition to studying living species, scientists examine the fossil evidence to trace back the lineage and transformation of species over time. The comparison of fossils, anatomical structures, and DNA sequences of different species helps to reconstruct the evolutionary history and to understand the mechanisms of evolution. In modern research, advances in genetics have empowered scientists to study the DNA of organisms, thereby providing a more detailed and molecular understanding of how species evolve.