I remember a conversation with somebody many years ago where we were discussing why organisms are diploid \u2014 that is, why do they have two copies of their genes? I said, \u201cMaybe because if one copy is defective due to mutation, the other one provides a backup.\u201d And the other person said, \u201cNo, this would be too simplistic.\u201d I didn\u2019t find out until 20 years later that I was probably onto something there, because there\u2019s now been a lot of work that suggests this could be one of the reasons why diploidy is abundant in nature. That was the first link to this concept of robustness: that diploidy can provide organisms with robustness to mutations.<\/p>\n

It\u2019s something that I rediscovered when I started working on gene regulatory networks. These model networks evolve through mutation and selection, and over time they become increasingly robust against disruptions by mutations. I became really fascinated with that.<\/p>\n

I realized that this kind of robustness could be linked to the ability of populations to explore many, many different genotypes during evolution without losing a phenotype that\u2019s well adapted. In doing so they could stumble on new phenotypes that they would not be able to otherwise. I\u2019m still fascinated by this link between the ability of biological systems to withstand perturbations \u2014 for example, mutations \u2014 and their ability to explore new things.<\/p>\n<\/div>\n

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