Heritability estimates were close to one for shell size and relative shell aperture, suggesting a low impact of environmental factors in embryos. Estimates of Qst between ecotypes were significant and typically much higher than published Fst estimates from neutral markers, indicating a role for selection on shaping additive genetic variation. Estimates of Pst between ecotypes for adults were substantially larger than embryos´ Qst, suggesting also a role of phenotypic plasticity in ecotype differentiation. Our results suggest that Pst vs Fst comparisons should be taken with caution because they might not reflect real additive genetic effects, but Pst vs Qst comparisons could shed light into the role of phenotypic plasticity.
I think that this comment in particular addresses an interesting highlight of the study: that heritability is high regarding shell traits, especially when snails are still developing. In simpler words, a snail's traits at first are almost completely determined by his genetics, but as he grows older his environment will become more involved. The Qst vs Fst comparisons help detail how both nature AND nurture play a vital role in a snail's genetic stability.