Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Sentence1: Pedigree A pedigree is a map of the types of hemoglobin in the family tree. 
Sentence2: a map of the types of hemoglobin in the family tree is a useful tool for studying inheritance patterns.
family

Sentence1: Adaptation traits contribute to individual fitness and to the evolution of animal genetic resources. 
Sentence2: Behaviors can improve the evolution of animal genetic resources.
animal

Sentence1: Bats use echolocation which is like sonar. 
Sentence2: echolocation is used by bats to find the location of an object.

echolocation