Which of the following is not one of the four main principles to the theory of natural selection?

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

Rank the three variables in terms of how strongly they affect the "species" composition of the bacterial communities. place the variable with the weakest effect on the left and the variable with the strongest effect on the right.

Nucleic acids offer variability because they contain alternate forms of genes called .