Which statement best describes a methodological weakness when studying evolution of behaviour?

Which statement best describes a methodological weakness when studying evolution of behaviour?

• A. It's hard to separate genetic influences from environmental influences
• B. Epigenetic effects are always negligible
• C. It is easy to separate genes from environment
• D. There is no interaction between genes and environment

Answer: (C)

The main idea is that teasing apart how much behaviour is shaped by genes versus by the environment is notoriously difficult when studying evolution of behaviour. In real life, genes and environment don’t act in isolation—their effects mix and influence one another across development. This makes it a methodological weakness to try to attribute behaviour to a single source without considering the other. Epigenetic changes show how environmental factors can alter gene expression, and gene–environment interactions mean the impact of a gene can depend on the context. Because of this, “separating genetic influences from environmental influences” is rarely straightforward in practice, which is why that option best captures the challenge. The other statements aren’t accurate reflections of the issue: epigenetic effects aren’t always negligible, there is clear gene–environment interaction, and it’s not easy to separate genes from environment.

The main idea is that teasing apart how much behaviour is shaped by genes versus by the environment is notoriously difficult when studying evolution of behaviour. In real life, genes and environment don’t act in isolation—their effects mix and influence one another across development. This makes it a methodological weakness to try to attribute behaviour to a single source without considering the other.

Epigenetic changes show how environmental factors can alter gene expression, and gene–environment interactions mean the impact of a gene can depend on the context. Because of this, “separating genetic influences from environmental influences” is rarely straightforward in practice, which is why that option best captures the challenge.

The other statements aren’t accurate reflections of the issue: epigenetic effects aren’t always negligible, there is clear gene–environment interaction, and it’s not easy to separate genes from environment.