Galen will establish the concept of humors (phlegm, blood, black bile and yellow bile) that determine both health and personality.
Belief in these four humors will dominate medicine and biology for many centuries. 180-Pausanias records a description of the skeleton of the hero Ajax.
A method for finding which phenotypes will invade a population; related to game theory.
The algae or bacteria live inside the fungus, and exchange nutrients with it. Lichens pose a problem for biological classification, because the three types of organism concerned come from three different kingdoms.
The lichen is different in shape and mode of life from any of the partners. After long debate, lichen are now classified as fungi, under the genus and species of the host fungus.
This allows specimens to be put into boxes and labelled.
By having specific names, researchers know what they are working on: that is one of the basic functions of taxonomy. In those fungi which may associate either with an alga, or with a cyanobacterium, the resulting forms (called photomorphs) may look quite different, yet are now referred to by the same name.
To line up different DNA, RNA, or protein sequences.