Which of the following words mean common ancestry with respect to evolution?

Options

A. Analogy
B. Homology
C. Ontogeny
D. Phylogeny

Explanation

To determine which word means "common ancestry" with respect to evolution, we can analyze the options provided:

1. **Analogy**: This term refers to similarities in function or appearance between different species that do not share a common ancestor. For example, the wings of a butterfly and the wings of a bird are analogous structures because they serve the same function (flight) but evolved independently.

2. **Homology**: This term refers to similarities in structure or genetics between different species that arise from a common ancestor. For example, the forelimbs of humans, birds, and whales are homologous structures because they share a common evolutionary origin, even though they may serve different functions.

3. **Ontogenic**: This term relates to the development of an individual organism from embryo to adult. It does not specifically refer to common ancestry among different species.

4. **Phylogenic**: This term relates to the evolutionary history and relationships among species. While it does involve common ancestry, it is more about the evolutionary tree and relationships rather than the term that directly means common ancestry.

From the analysis, the correct answer is **homology** because it specifically refers to similarities that indicate a common evolutionary ancestor.

### Step-by-Step Solution:
1. **Identify the terms**: Look at the four options provided: analogy, homology, ontogenic, and phylogenic.
2. **Define each term**: Understand what each term means in the context of evolution.
3. **Analyze the relevance**: Determine which term specifically indicates common ancestry.
4. **Select the correct answer**: Conclude that "homology" is the term that means common ancestry with respect to evolution.