How do fossils support the ideas of common ancestry and evolution?

Answer 1

Fossils are preserved remains or imprints of organisms that are formed in rock layers. When an organism dies, sediments may form on top of it, burying and preserving it. Another organism may die on top of it and also be buried. Eventually, many different rock layers (also known as strata) are formed with fossils inside them. So we can say that the lower the strata, the older the rock and fossil. The higher the strata, the younger the fossil. This is because new rocks and fossils form on top of older ones. When studying the fossils found in different strata, scientists found that the older ones were a lot more simpler. This means that fossils formed millions and millions of years ago were once very simple organisms. As they observed fossils higher up in the different strata, they noticed that there were similar fossils but they were a little bit more developed and complex. The newest fossils found resembles organisms that exist today. This shows that organisms were once very simple, but, with time, became more complex and better suited for survival in particular conditions. This is known as evolution.

The fossil record is only one of many types of evidence for evolution.

Answer 2

AnswerScientists consider the process of evolution to be well proven even without the fossil record. In fact, Charles Darwin did not rely much at all on the fossil record in developing his Theory of Evolution by Natural Selection. However, the fossil record adds considerable weight to the theory.

The fossil record shows clear evidence of evolution over a period of more than a billion years. Certainly, at first, there were no transitional species among the many species that had been found, although scientists saw much that did confirm the Theory of Evolution. That has changed, because many transitional species have been found. A recently discovered 220-million year old fossil, Odontochelys semitestacea, is a new species of turtle that had a fully formed shell on its underside, but only a small partial shell on its back, extending from its backbone. As well as a partial shell, Odontochelys semitestaceaalso had ribs that had begun to widen, thus demonstrating that the fully developed shell of later turtles evolved from the ribs of earlier species. Tiktaalik roseae is the name of a newly discovered lobe-finned fossil fish from the late Devonian period, that is a transitional form to amphibians, with basic wrist bones and simple fingers, as well as the robust ribcage necessitated by existence out of water. Odontochelys semitestacea and Tiktaalik roseae are two more pieces in the jigsaw that shows conclusively how life on Earth evolved from earlier species.

The numerous extinctions that took place over this time can not be put down to a single legendary event, such as the biblical Noah's Flood. Extinctions occurred from time to time, with no set pattern, although there were three great periods of catastrophic extinctions, the last of which eliminated the dinosaurs. Moreover, scientists regularly see a new species arising in the fossil record, becoming gradually more numerous, stabilising in numbers for a very long period, then tapering off prior to final extinction. None of this is consistent with a Flood hypothesis.

Answer 3

Fossils are used to support the occurrence of evolution because fossils show intermediate forms of organisms that have existed in the past.

For example, let's say that there is an animal that lived 40 million years ago, and it had 3 toes. Then, another animal, which is very similar, is found in layers dating to 30 million years ago, but it has only 2 toes. And then, an animal very similar to the second animal, but having only 1 toe, is found in rock layers dating to 20 million years ago.

Of course, this is dramatically simplified, because never is only one trait changed at a time in evolution, but hopefully this example will help!

Answer 4

The fossil record is not needed to prove that evolution occurred. In fact, Charles Darwin formulated his Theory of Evolution without reference to the fossil record.


The fossil record does allow scientists to see just how evolution really did happen. They can place fossils in sequence so that they can see the progression, over time, from an earlier species to much later ones. As transitional species are found in the fossil record, they can be shown to fit into the fossil sequence in just the right place to explain evolution.

Answer 5

Because as life evolved, it left traces of fossil remains documenting its change through time.