ancestor
Noun

organism from whom one is descended.

cnidarian
Noun

large phylum of aquatic animals (such as jellies and corals) characterized by radial body symmetry and stinging tentacles.

evolution
Noun

change in heritable traits of a population over time.

genetic
Adjective

having to do with genes, inherited characteristics or heredity.

invertebrate
Noun

animal without a spine.

mammal
Noun

animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

organism
Noun

living or once-living thing.

phylogenetics
Noun

study of how organisms relate to each other as they develop over time.

species
Noun

group of similar organisms that can reproduce with each other.

vertebrate
Noun

organism with a backbone or spine.