Editing Effective population size (section)

==== Non-Fisherian sex-ratios ====

When the [[sex ratio]] of a population varies from the [[Ronald Fisher|Fisherian]] 1:1 ratio,  effective population size is given by:

:<math>N_e^{(v)} = N_e^{(F)} = {4 N_m N_f \over N_m + N_f}</math>

Where ''N''<sub>''m''</sub> is the number of males and ''N''<sub>''f''</sub> the number of females.  For example, with 80 males and 20 females (an absolute population size of 100):
:{|
|-
|<math>N_e</math>
|<math>= {4 \times 80 \times 20 \over 80 + 20}</math>
|-
|
|<math>={6400 \over 100}</math>
|-
|
|<math>= 64</math>
|}

Again, this results in ''N''<sub>''e''</sub> being less than ''N''.