How can fossils provide evidence for evolution?

Hint: A fossil is a dying organism's frozen bones from millions of years ago. In rocks of all ages, fossil fossils have been discovered. In the oldest rocks, fossils of the simplest creatures are found, and in the newest rocks, fossils of more complex species.

Complete answer:
Species have altered when life progressed on Earth through researching fossils. As many early forms of life were soft-bodied, there are holes in the fossil record, which means they have left few traces behind. Geological activities may have lost what traces there were. That's why scientists can't be sure how life started.
In rocks, fossils are present and can be formed from:
1.Strong pieces of the body, such as bones and shells, do not readily die or are replaced by minerals as they decay.
2.Since one or more of the conditions necessary for decay are missing, parts of species that have not decayed. Dead animals and trees, for example, may be frozen in amber, peat bogs, tar pits or ice.
3.Preserved remains of life, such as tracks, burrows and rootlet traces, are hidden by soil deposits that gradually become rock.
Fossils offer a snapshot of history and allow us to research how little or how much species have evolved on Earth as life grew.

Note:To build a fossil record, scientists will use all the fossil specimens that have been discovered so far. It is possible to organise the different fossils to demonstrate how organisms have evolved over time and how various species are related. The fossil record, however, also reveals very dramatic shifts in species. This makes sense because the record is far from full, and the probability that after death an organism will be fossilised is currently very minimal.

There are two other hypotheses which may explain why these drastic shifts are being noticed by scientists.According to the principle of punctuated equilibrium, over long stretches of time, ecosystems remain largely stable with brief bursts of sudden transition that produce new organisms.
Gradualism, on the other hand, implies that ecosystems experience several minor changes that build up and ultimately form new species over a long period of time