9.1 An engineering challenge

On July 30, 2020, NASA and its collaborators launched the Perseverance rover on a 292,526,838 mile journey to Mars. The following February, they dropped the rover into a 4-by-7 mile target near the edge of Jezro crater. This feat of engineering demonstrated, among other things, that the mission’s engineers understand a thing or two about gravity, thrust, and inertia.

The Perseverence mission. Credits (clockwise from upper left): NASA / Joel Kowsky; NASA / JPL-Caltech; NASA; ESA / DLR / FU-Berlin / NASA / JPL-Caltech

The rover’s mission was to search for signs of ancient life, but on March 16 it paused for a selfie in front of Mont Mercou:

Selfie at Mont Mercou. (NASA / JPL-Caltech / MSSS)

If we understand genetics and evolution as well as we think we do, we should be able to do something analogous with living organisms. We should be able to:

Design and build our own gene,

Put it into the genome of a living organism, where it will alter the fitness—in a precise way—of the individuals who carry it, and

Accurately predict how our gene’s frequency will change across many generations in a population.

Scientists have succeeded at this challenge using multiple strategies. Here we consider a strategy implememted by Kyros Kyrou, Andrew M. Hammond, and colleagues. Working with a laboratory population of Anopheles gambiae mosquitoes, these scientists initiated a mutagenic chain reaction caused by a gene drive.