Final answer:
Charles Darwin did not immediately recognize the Galápagos birds as finches; this understanding came after careful observation and study. The variation in beak sizes and shapes among the finches, which corresponded to their food sources and environments, became a key example of adaptive radiation and contributed to Darwin's theory of evolution.
Step-by-step explanation:
It is false that Charles Darwin was able to immediately identify the birds he collected on the Galápagos as finches. When Darwin first observed the birds on the islands during his voyage on the HMS Beagle, he initially did not realize that they were all finches. Only upon further study did he recognize that these birds were not only related to each other but were also distinct species adapted to their respective islands. The birds exhibited variations in their beak sizes and shapes, which closely correlated with their food sources, such as seeds or insects. This observation was a pivotal moment in his development of the theory of natural selection, as he realized these variations and adaptations were evidence of species evolving over time. The concept of adaptive radiation is illustrated by Darwin's finches. Adaptive radiation refers to the process by which organisms diversify rapidly from an ancestral species into a multitude of new forms when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches. The different beak structures of the finches allowed each species to specialize in a different type of food acquisition, representing an excellent example of adaptive radiation and contributing to the evidence supporting the theory of evolution.