Which evolutionary theory is opposed to Darwinian evolution due to its idea of perfect blending?

The correct choice reflects the concept of Lamarckian blending, which is associated with Jean-Baptiste Lamarck's early theories of evolution. Lamarck proposed that traits acquired during an organism's lifetime could be passed on to its offspring, leading to a gradual change in species. This idea promotes the notion of perfect blending, suggesting that offspring would inherit a mix of traits from their parents, resulting in a loss of distinctiveness over generations.

This theory contrasts sharply with Darwinian evolution, which emphasizes natural selection as a key mechanism for evolution. Unlike Lamarck's views, Darwin argued that heritable traits that confer advantages in survival and reproduction would be favored over generations, leading to evolution through differential survival rather than blending. Therefore, Lamarckian blending is incompatible with the fundamental principles of Darwinian evolution, making this choice the correct answer.

In contrast to Lamarck's blending theory, macroevolution refers to large-scale evolutionary changes that occur over extended periods, and the modern synthesis integrates genetics with natural selection, both of which greatly support Darwinian concepts rather than oppose them.