Q
Why do we have different hand shapes?
A
Expert Answer
Hand proportions are influenced by: genetics (HOX genes control limb development), hormones (testosterone affects finger length ratio—2D:4D), climate adaptation (Bergmann's and Allen's rules), and sexual selection. Hand proportions correlate with some traits but predictions are weak.
Key Insight
Hand proportions are influenced by: genetics (HOX genes control limb development), hormones (testosterone affects finger length ratio—2D:4D), climate adaptation (Bergmann's and Allen's rules), and sexual selection.
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