CIESE: Human Genetics: Survey Traits
Observable Genetic Traits
Earlobes: Free ear lobes (dominant trait) vs. Attached ear lobes (recessive trait)
Forelock: White forelock (dominant trait) vs. No white forelock (recessive trait)
Dimples: Dimples (dominant trait) vs. No dimples (recessive trait)
Thumbs: Straight thumb (dominant trait) vs. Curved thumb (recessive trait) When viewed from the side as in the illustration below, curved thumbs can be seen as part of a circle.
Mid-digit hair: Mid-digit hair (dominant trait) vs. No mid-digit hair (recessive trait) Look for hair only on the finger shown by the white arrow below.