Natural selection at work
Scientists have worked out many examples of natural selection, one of the basic mechanisms of evolution.
Any coffee table book about natural history will overwhelm you with full-page glossies depicting amazing adaptations produced by natural selection, such as the examples below.
In some cases, we can directly observe natural selection. Very convincing data show that the shape of finches' beaks on the Galapagos Islands has tracked weather patterns: after droughts, the finch population has deeper, stronger beaks that let them eat tougher seeds.
In other cases, human activity has led to environmental changes that have caused populations to evolve through natural selection. A striking example is that of the population of dark moths in the 19th century in England, which rose and fell in parallel to industrial pollution. These changes can often be observed and documented.
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Orchid and wasp image courtesy of Colin Bower; Heart Cockle image courtesy of Avril Bourquin; Katydid image © Greg Neise, GE Neise Digital Communication; Snake images courtesy of Neurotoxin; Blue-footed booby image courtesy of Ian Skipworth.
Understanding Evolution © 2015 by The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California