Organisms that are best suited to their environment survive and reproduce with the greatest success. Any organisms that are not well suited to their environment soon die out. As a result of this natural selection, species evolve with particular traits—biological adaptations—that allow them to better survive in their habitats. One such adaptation is freeze tolerance, which allows certain organisms to survive in very cold habitats.
Take the common wood frog, for example, which are found in the northern United States and Canada. In this video from NOVA scienceNOW, students learn how the common wood frog endures freezing cold temperatures for parts of the year. In order to survive the cold, they have a special adaptation—they are able to freeze solid without damaging their cells.
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