Which of the following did not influence Darwin as he synthesized the theory of evolution by natural selection?
a. Examples of artificial selection that produce large and relatively rapid changes in domesticated species.
b. Lyell's Principles of Geology, on gradual geologic changes.
c. Comparisons of fossils with living organisms.
d. Mendel's paper describing the laws of inheritance.

Verified step by step guidance

1. Step 1: Begin by understanding the context of Darwin's theory of evolution by natural selection. Darwin synthesized his theory based on observations and influences from various sources, including geology, biology, and artificial selection.
2. Step 2: Analyze each option provided in the question to determine its relevance to Darwin's work. For example, artificial selection (option a) was a key influence as Darwin observed how humans could breed animals and plants to produce desired traits.
3. Step 3: Consider Lyell's Principles of Geology (option b). This work introduced the concept of gradual geological changes over time, which influenced Darwin's thinking about gradual biological changes and the timescale required for evolution.
4. Step 4: Examine the comparison of fossils with living organisms (option c). Fossil evidence provided Darwin with insights into how species changed over time and supported the idea of common ancestry.
5. Step 5: Evaluate Mendel's paper on the laws of inheritance (option d). Mendel's work was published during Darwin's lifetime but was not widely recognized or understood until after Darwin's death. Therefore, Mendel's paper did not influence Darwin's synthesis of the theory of evolution by natural selection.

Key Concepts

Natural Selection

Natural selection is a fundamental mechanism of evolution proposed by Charles Darwin. It posits that individuals with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to the next generation. This process leads to gradual changes in populations over time, shaping the diversity of life.

Artificial Selection

Artificial selection is the intentional breeding of organisms by humans to produce desired traits. This concept was crucial for Darwin as it demonstrated how selective pressures could lead to significant changes in species over relatively short periods, providing a model for understanding natural selection in the wild.

Geological Gradualism

Geological gradualism, as articulated by Charles Lyell, suggests that the Earth's features are the result of slow, continuous processes over long periods. This idea influenced Darwin by providing a framework for understanding how gradual changes in the environment could lead to the gradual evolution of species, aligning with his observations of natural selection.