If the correlation between flowering dynamics and cell wall biosynthesis were spurious, mutations affecting cell wall composition in evolutionarily related species with different flower morphology would not show association with flowering dynamics.

A mutation linked to lactase persistence shows very strong evidence of adaptive evolution in European and American populations (Williamson et al. 2007), populations where pastoral farming for milk has been historically important.

Conversely, there is also the same amount of evidence that mutations show no epistasis (purely additive model) or antagonistic interactions (each additional mutation has a disproportionally small effect).

Such mutations often show pleiotropic effects and may cause a cost of resistance.

Except for A364V, mutations in the CA/SP1 cleavage site have showed to result in fitness deficits when combined with protease inhibitor resistance.

Furthermore, such mutations can show how the specific structure of that region of a chromosome affect expression levels and function.

In individuals with bladder, head and neck, and lung cancers the point mutations within the coding region showed signs of being homoplasmic (resembling each other).

The other mutations show either increased (S435F) or decreased (F525N) surface expression but also with increased affinity for cAMP and cGMP.

Similar mutations on yeast showed destabilization of the protein and decreased substrate affinity.

Marfan syndrome affects males and females equally, and the mutation shows no ethnic or geographical bias.