Key observations supporting Darwin's theory of evolution by natural selection include the inheritance of traits, the presence of heritable variations that influence an organism's fitness, and the observation of species on the Galápagos Islands that are uniquely adapted to their environment.
Support for Darwin's Theory of Evolution by Natural Selection
- Observations that support Charles Darwin's concept of evolution through natural selection are varied and stem from numerous scientific disciplines.
- Firstly, Darwin observed that offspring have variations and those with favorable variations are more likely to survive and reproduce, leading to these traits being passed to future generations.
- Secondly, Darwin and Alfred Russel Wallace both noted that traits among individuals in a population vary, and these traits are inherited.
- The competition for limited resources selects for individuals with traits better adapted to their environment.
- Additionally, Darwin's observation of animals on the Galápagos Islands showed that they were well-suited to their specific environments, suggesting that species evolve over time due to natural selection.
- Finally, both Darwin and Wallace used the principles first outlined by economist Thomas Malthus regarding population pressure and limited resources to explain how only those with advantageous traits would survive, reproduce, and pass on those traits, driving evolutionary change over generations in a process known as descent with modification.
- The concept of fitness also provides support for Darwin's theory, referring to an organism's capacity to survive and produce fertile offspring.
- Nature, as Darwin stated, selects the variations most useful for survival and reproduction, leading to evolutionary change over time.