breed – n. a kind of animal

extinct – adj. no longer existing in nature

DNA – n. short for deoxyribonucleic acid -- a substance that carries genetic information in the cells of plants and animals

howl – n. a long, sad sound made by a dog or wolf

overtone – n. something that is suggested, but not clearly stated

predecessor – n. something that comes before another thing in time or in a series

sample – n. a small amount of something that gives you information about the thing it was taken from

sequence – n. the order in which nucleotides (chemical substances) are combined with DNA

in essence – phr. relating to the most important characteristics or ideas of something