Use the Fitch Algorithm to Determine the Minimum Number of Evolutionary

question 15

Essay

Use the Fitch algorithm to determine the minimum number of evolutionary changes required to explain the character states (square,circle,or star)of the seven species depicted on the tree in the figure above.Recall the rules for assigning character states as you work your way down the tree.
1.If each of the two daughters of a node shares one or more possible states for a trait,assign those shared traits to the node in question.
2.If the two daughters share no possible states in common,assign all possible states for both daughters to the node.(Note to instructor: The difficulty of this question can be adjusted by including or omitting the two rules above.)

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Definitions:

Hertz

The unit of frequency in the International System of Units (SI), equating to one cycle per second.

Auditory Neuron

a nerve cell that is involved in the process of hearing, transmitting auditory signals from the ear to the brain.

Pitch

Pitch refers to the perceived frequency of a sound, determining how "high" or "low" it sounds.

Basilar Membrane

A membrane running the length of the cochlea; sound waves cause a deformation of this membrane, bending the hair cells in the cochlea and thus stimulating the auditory receptors.