ancestral trait

an evolutionary trait that is homologous within groups of organisms (see homology) that are all descended from a common ancestor in which the trait first evolved. Because an ancestral trait may occur across many species—for example, opposable thumbs in marmosets, ring-tailed lemurs, and gorillas—it cannot be used to further elucidate their genetic relationships.

Browse dictionary by letter

a b c d e f g h i j k l m n o p q r s t u v w x y z

Psychology term of the day

February 17th 2025

mammography

n. a diagnostic procedure that uses low-dose X-ray photography to detect breast tumors or other abnormalities, either noncancerous (benign) or cancerous (malignant). The X-ray negative produced is called a mammogram.