We’ll use stem cell technologies to expand the number of eggs that prospective mothers can use in IVF and therefore the range of reproductive options for parents.We’ll deploy gene editing tools far more precise than today’s CRISPR systems to make heritable genetic changes to our future offspring.Over the coming decades, Darwin’s original concept of random mutation and natural selection will gradually give way to a process that is far more self-guided than anything Darwin could have imagined.The Economist: Changing the nature of what it means to be human has huge consequences.What are the main ones?Mr Metzl: We have internalised the idea that information technology is variable, which is why we expect each generation of our phones and computers to be better than the last.It’s harder for us to come to grips with the idea that our biology could be as variable as our IT, even though we understand intellectually that somehow we evolved from single cell organisms to complex humans over the past 3.8 billion years.