Final answer:
The Galápagos finches demonstrate evolution by natural selection, where environmental changes led to a shift in beak size among the medium ground finch population, as documented by Peter and Rosemary Grant.
Step-by-step explanation:
The Galápagos Islands offer a fascinating glimpse into evolution by natural selection, particularly through the study of Galápagos finches. Biologists Peter and Rosemary Grant have provided compelling evidence of this process by documenting changes in finch beak size over several generations. For instance, they observed that during periods of high rainfall caused by El Niño, small seeds became abundant while large, hard seeds were scarce. Finches with smaller, thinner beaks were more adept at eating these small seeds, leading to a higher survival and reproduction rate among them. As a result, the average beak size within the finch population decreased over time, a clear example of natural selection at work, driven by environmental changes.
The medium ground finch of Daphne Major is a prime example of how inherited traits can evolve. Following the El Niño event, the Grants' meticulous measurements indicated a shift toward smaller beak sizes due to the lack of larger seeds. Their studies reiterate the power of natural selection in shaping the morphology and survival of species.
The Galápagos Islands, with their unique ecosystems and varied environments, have historically proven indispensable in contributing to our understanding of evolution. The protection of these islands and conservation of their native species remain critical to ensuring that they continue to provide insights into the evolutionary process for future generations.