Evolution — BIOLOGY STD 12 Science — Question

→ Evidence of the emergence and development of life on earth is obtained from many directions.
→ Fossils are the hard parts of life forms in rocks.
→ Rocks, sediments and layers of the Earth's layers indicate the layering of organic elements over Earth's long history.
→ Sedimentary rocks of different ages contain fossils of different life forms that must have died out during the formation of these particular rocks.
→ Some of them show similarities with modern organisms. They represent extinct organisms.
→ This study shows that life-forms change with time. And some life-forms do not change for certain planetary periods.
→ Therefore, new life-forms have come into existence at different times in the history of the earth.
→ All this is called fossil evidence.
The age of fossils can be known by the method of radioactivity-dating.