The phenotype of organisms is shaped by the interaction between environmental factors and their genetic constitution. A recent study by a team of population geneticists shows that fruit flies live in a sort of genetic comfort zone at a specific temperature. The scientists found that, despite their underlying genetic differences, two separate strains of flies had a very similar gene expression pattern at 18°C. This effect of 'canalization', which has also been described in humans, allows organisms to continue to grow and develop stable even in the face of genetic and environmental stress.

Source: Living in genetic comfort zone: How to avoid influence of genetic variation