Question
Multilocus heterozygosity (MLH) is reflective of genetic quality; according to sexual selection research, it is thought that sexual ornamentation functions as a visual indicator of fitness. By selecting males with features such as bright coloration, females can improve the chances of reproductive success. Male guppies are covered in a mixture of colored spots; orange coloration is consistently preferred by females. Heterozygosity was assessed by genotyping 9 loci and calculating the proportion of loci that are heterozygous. The research question of interest is whether MLH and orange color are linearly associated.

(a) Based on the plot of MLH versus relative orange area, describe the nature of the association in language accessible to a general audience.

(b) Comment on whether the assumptions of linearity and constant variability are reasonably met.

(c) Comment on whether the residuals are approximately normally distributed.

0.20- 0.10- 0,15- 0.10- 0.05 02 0.3 0.4 0.5 0.6 0.7 0.8 MLH 0.05- 0.00 -0.05 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Relative Orange Area 0.10- 0.05 0.00- -0.05- Q-Q Plot of Residuals T -1 0 1 2 Theoretical Quantiles