what is the key to the recognition of a trait whose expression is determined by the effects of two or more genes

Explanation:

Polygenic inheritance occurs when many loci of a gene contributes to it genetic make up.

No particular allele can be selected for contributing to a particular traits all the allele are equally expressed.

Over expressitivity example is pleiotrophy effect have more than 5 fingers or toes

The offspring express more dominant traits that the normal mendelian principle

This signs indicate polygenic inheritance.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.