There are currently 1.8 million known species on the planet. How would you organize them into groups?
Taxonomy – the identification, naming, and classification of a species All life is classified into three Domains:
Within each Domain, life is categorized further into KINGDOM PHYLUM CLASS ORDER FAMILY Genus species Use a mnemonic to remember! K ing P hilip C ame O ver F rom G ermany S aturday
In order to organize living things, scientists use cladograms to show, in a visual way, the relationships between organisms.
For example, if I wanted to construct a cladogram that shows the relationship between kangaroos, earthworms, amoeba, lizard, cat, sponge, and salmon: segmented jaws hair placenta multicellular limbs kangaroo + + + - + + earthworm + - - - + - amoeba - - - - - - lizard + + - - + + cat + + + + + + sponge - - - - + - salmon + + - - + - Cladogram
Using homologous structures and molecular data, scientists construct a specific kind of cladogram called a phylogenetic tree Branch lengths are proportional to the evolutionary time between related organisms Life is classified according to evolutionary relationships .
However, scientists must be careful and make sure that structures are truly homologous and are not analogous . Convergent evolution is a process in which unrelated species from similar environments have adaptations that are very similar These adaptations are called Analogous Structures and are NOT due to a recent common ancestor.