How do fossils provide evidence for evolution?

Fossils provide evidence for evolution by showing how species have changed and developed over millions of years.

Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. They are crucial in providing a record of life on Earth and are a primary source of evidence for evolution. By studying fossils, scientists can observe and analyse the physical characteristics of ancient organisms and compare them to those of modern species. This allows them to trace the evolutionary history of these species, showing how they have evolved and adapted over time.

For example, the fossil record shows a progression from simple, single-celled organisms to more complex, multicellular organisms. This supports the theory of evolution, which states that life on Earth started as simple organisms and gradually evolved into the diverse array of species we see today.

Fossils also provide evidence for the concept of 'descent with modification', a key principle of evolution. This principle suggests that species change over time, with new species arising and old ones becoming extinct. Fossils can show these changes in a species over time, such as changes in size, shape or structure. For instance, the fossil record of horses shows a gradual increase in size and changes in the structure of their teeth and limbs, reflecting adaptations to changing environments.

Moreover, fossils can show transitional forms, which are species that have characteristics of both ancestral and derived species. These transitional fossils are particularly important as they provide direct evidence for the process of evolution. A famous example is Archaeopteryx, a fossil bird that shows features of both dinosaurs (its ancestors) and modern birds.

In conclusion, fossils provide a tangible and visual record of how life has evolved on Earth. They allow scientists to trace the lineage of species, observe changes in their characteristics over time, and identify transitional forms, all of which provide compelling evidence for the theory of evolution.