The best-adapted individuals were selected by nature to survive and leave offspring for the next generation. Darwin called this mechanism

Answer

The mechanism that Darwin referred to is known as Natural Selection. Natural selection is a key component of Charles Darwin's theory of evolution and explains how species evolve over time through the differential survival and reproduction of individuals with advantageous traits.

1. Survival of the Fittest: The phrase “survival of the fittest” is often associated with natural selection, implying that individuals who are better adapted to their environment tend to survive and produce more offspring. It is important to understand that "fittest" does not necessarily refer to strength, but rather to a combination of traits that are beneficial in a specific environment.

2. Variation: In any given population, there is natural variation in traits. These variations can be due to genetic differences. For example, in a population of birds, some may have longer beaks while others have shorter beaks.

3. Heritability: The advantageous traits have to be heritable, meaning they can be passed down from parents to offspring. This is crucial for the propagation of traits throughout generations.

4. Reproductive Advantage: Individuals with traits that give them an edge in survival and reproduction will pass on these traits to their offspring, leading to a gradual change in the population's characteristics over many generations.

In summary, natural selection is the process through which favorable traits become more common in a population, thus contributing to the evolution of species. This mechanism is central to our understanding of how life adapts to changing environments and how complex biological systems develop over time.