Yes, evolution by natural selection is a scientifically established fact. The concept of evolution, including the process of natural selection as the primary mechanism driving it, is supported by an overwhelming amount of evidence from multiple scientific disciplines.
The evidence for evolution comes from various sources, including:
Fossil Record: The fossil record provides a rich source of evidence showing the existence of organisms that lived in the past and how they have changed over time. Fossil discoveries demonstrate the gradual transitions and the appearance of new species throughout Earth's history.
Comparative Anatomy: The similarities and differences in anatomical structures among different species provide evidence of common ancestry. Homologous structures, such as the bones in the limbs of humans, bats, and whales, share a common origin but have been modified for different functions in different species.
Embryology: The similarities in the embryonic development of different organisms reflect their shared evolutionary history. Many organisms go through similar stages of development, showing common patterns that point to a common ancestry.
Genetics and Molecular Biology: The study of DNA and genetics provides strong evidence for evolution. DNA sequencing and comparative genomics reveal similarities and differences in genetic sequences among different organisms, allowing scientists to reconstruct evolutionary relationships and trace the patterns of inheritance.
Biogeography: The distribution of species across different regions of the world is consistent with patterns predicted by evolution. Species in different regions often share common ancestry and show adaptations to their specific environments.
Experimental and Observational Studies: In addition to the wealth of historical evidence, scientists have conducted numerous experiments and observations that directly demonstrate evolutionary processes in action, such as the evolution of antibiotic resistance in bacteria or the observed changes in populations of finches in the Galapagos Islands.
The theory of evolution by natural selection, first proposed by Charles Darwin and Alfred Russel Wallace in the 19th century, provides the explanatory framework for understanding the observed patterns and mechanisms of evolutionary change. It has withstood extensive scrutiny, testing, and refinement over time and is considered one of the fundamental principles of modern biology.