02:44
Genetics: A Conceptual Approach
A geneticist studies a series of characteristics in monozygotic twins and dizygotic twins, obtaining the concordances listed below. For each characteristic, indicate whether the rates of concordance suggest genetic influences, environmental influences, or both. Explain your reasoning.
$$\begin{array}{lcc}
& \multicolumn{2}{c} {\text { Concordance (\%) }} \\
\)\cline { 2 - 3 }\( \text { Characteristic } & \text { Monozygotic } & \text { Dizygotic } \\
\text { Migraine headaches } & 60 & 30 \\
\text { Eye color } & 100 & 40 \\
\text { Measles } & 90 & 90 \\
\text { Clubfoot } & 30 & 10 \\
\text { High blood pressure } & 70 & 40 \\
\text { Handedness } & 70 & 70 \\
\text { Tuberculosis } & 5 & 5
\end{array}$$