A View from Emily Singer
A Plan to Create Life but Not as We Know It
What life on another planet might look like, and other tidbits.
The future of life and the origin of life are two big questions that often get intertwined. Attempts to create life from scratch could shed light on how it evolved, and on how it might be engineered in the future. Several prominent scientists, including genomics pioneers Craig Venter and George Church and biologist Jack Szostak, reflected on these questions and more at the Future of Life symposium at Harvard last weekend. Here’s a sampling of interesting tidbits from their talks.
Re-creating alien life:
Harvard’s Szostak has been a pioneer in attempting to re-create the origins of life. His lab has shown that lipids and RNA can spontaneously assemble under conditions resembling those of early Earth, and it’s now trying to create RNA that can replicate–another prerequisite for life. Szostak’s team is also thinking about what life might look like beyond Earth. “We want to see if we can make living systems by design that can live in totally different environments,” he said at the conference. One of Mars’s moons, for example, has a lake of liquid hydrocarbons, such as methane, rather than liquid water. So Szostak’s lab is attempting to engineer life that can survive in these conditions. The researchers have so far been able to make membranes in these solvents.
Engineering long-lived rodents:
With its moist pink skin and immense buck teeth, the naked mole rat is no beauty. But what it lacks in comeliness, it makes up for in longevity. The rodent can live for nearly 30 years–more than 10 times longer than its cuter, furrier cousin, the mouse. A new project in George Church’s lab will try to figure out why. Church will use novel gene transfer methods to introduce into lab mice approximately 30 genes that are thought to play a role in longevity in the naked mole rat.
Scouring the planet’s genetic diversity:
According to Craig Venter, most of the world’s genetic diversity has yet to be discovered. During his envious trip around the globe–spent on his yacht collecting microbes in water samples from Mexico to Nova Scotia–Venter said that 85 percent of the genome sequences he and his team collected every 200 miles were unique. While gene discovery in mammals is largely saturated (meaning that most gene families have already been discovered), “you can find new gene families from bacteria just about everywhere you look,” he said.
Venter and his team haven’t just been sequencing sea life: they are examining the genomes of the microbial inhabitants of our bodies as well. Case in point: the approximately 1,000 species of microbes in our mouths contribute 4,000 genes. Compared with the approximately 20,000 genes in the human genome, that’s a significant contributor to genetic diversity, said Venter.