Question

How does palaeontological evidence support the theory of organic evolution? Explain with an example.

Answer 1

Palaeontological evidence supports the theory of organic evolution by showing a gradual change in organisms over geological time as recorded by fossils preserved in different layers (strata) of the Earth’s crust. Fossils provide direct evidence of past life forms and the sequence in which they appeared, linking simple ancestral species to more complex modern species.

For example, the fossil bird Archaeopteryx lithographica, which lived about 170 million years ago during the Jurassic period, exhibits characteristics of both reptiles and birds. Its reptilian features include teeth in jaws, a long tail with free vertebrae, and solid bones, while its avian features include feathers and wings. This combination of traits shows a transitional form,providing evidence that birds evolved from reptilian ancestors. Such fossils serve as “missing links,” bridging different groups of organisms in the evolutionary chain.

Another example is the evolution of the modern horse documented through fossils over approximately 60 million years. Changes have been observed in body size, limb structure, and teeth morphology, illustrating a gradual adaptation from ancestral forest-dwelling browsers with multiple toes to a large, single-toed, grassland-adapted runner.