heredity and evolution
Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past.
The fossil records of geological timescale shows that fossils of only simple forms are found in lower or old strata while those of complex forms appear in upper or recent strata of the earth. This indicates that complex forms have been gradually evolved from preexisting simple ones. Fossil dating also gives us an idea about the age of the fossil. A study of fossils in different sedimentary layers indicates the geological period in which they existed. This study shows that life-forms varied over time and certain life forms are restricted to certain geological time-spans. Hence new forms of life have arisen at different times in the history of Earth.
Fossils also reveal such forms like Neuropteris and Archaeopteryx, serving as connecting links. These connecting links clearly indicate the evolution of one organism from the other.
Some ancient animals, such as trilobites, have no close living relatives. Others have very close relatives living today. By studying living animals and how they live, scientists can better understand how animals lived in the past.
Fossils are an important piece of proving the theory of evolution because they present the physical proof of its' existence. Fossils are our only clues to life in the past. They help us learn about evolution - how living things have changed through time. It presents visible records of evolutionary changes in the strata of earth where there is no room for speculation or doubt.