CURRENT AFFAIRS

Detailed explanation-1: -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-2: -Of the millions of fossils that have been found, there are more than 250, 000 identified fossil species. Even in species with hard parts, which are more likely to be preserved, it is estimated that 85-97% of these most fossilizable species have never been fossilized.

Detailed explanation-3: -Most fossils “hide out” in sedimentary rock . When tiny bits of rocks and minerals (called sediment) join together over millions of years, they become sedimentary rock. Plants and animals that become sandwiched in this sediment eventually turn into fossils. Two examples of sedimentary rocks are sandstone and shale.