LIFE SCIENCE

Detailed explanation-1: -Structures that have lost their use through evolution are called vestigial structures. They provide evidence for evolution because they suggest that an organism changed from using the structure to not using the structure, or using it for a different purpose.

Detailed explanation-2: -Fossils document the existence of now-extinct species, showing that different organisms have lived on Earth during different periods of the planet’s history. They can also help scientists reconstruct the evolutionary histories of present-day species.

Detailed explanation-3: -Fossils provide important evidence for evolution and the adaptation of plants and animals to their environments. Fossil evidence provides a record of how creatures evolved and how this process can be represented by a ‘tree of life’, showing that all species are related to each other.

Detailed explanation-4: -These structures, which are often reduced in size, are known as vestigial structures. Examples of vestigial structures include the tailbone of humans (a vestigial tail), the hind leg bones of whales, and the underdeveloped legs found in some snakes (see picture at right).