دليل التطور

Life on Earth shows remarkable diversity. Multiple lines of research provide strong evidence that evolution produced this diversity.

Some evidence comes from direct observation. Scientists can observe the evolution of antibiotic resistance in bacteria.

Because bacteria multiply rapidly, random mutations appear frequently. Some of these mutations allow certain bacteria to survive exposure to antibiotics. Over time, bacteria with mutations that confer antibiotic resistance have a survival advantage.

Developmental biology also provides evidence for evolution. Early vertebrate embryos share similar structures, such as pharyngeal arches and a post-anal tail. These shared features reflect common ancestry. As development continues, embryos gradually develop traits that define their species.

Comparative anatomy also supports evolution. For example, birds, humans, and whales share a common ancestor. This relationship is reflected in their similar forelimb bone structures, even though these limbs perform different functions today.

The fossil record gives another important line of evidence. Fossils show that many species lived in the past but are now extinct.

Scientists can sometimes date fossils d