How Life Began

Erin O’Donnell in Harvard Magazine:

HOW DID LIFE begin on Earth? On a young, rocky planet, how might chemicals have come together in just the right way to form the very first cells? How did those primitive cells start behaving like life: growing, dividing, and passing on advantageous traits to the next generation? The origins of life are especially murky because the geological record—the layers of rock and embedded fossils that hold clues about the history of Earth and life—disappears at roughly 3.9 billion years ago, erased by movements in the planet’s crust. As a result, scientists lack direct evidence for conditions on early Earth, including proof of the molecules that might have swirled in primordial ponds and formed the building blocks of life. This presents a host of questions, precisely the kind of big questions to which Jack Szostak is drawn. He and others believe they can reconstruct in the lab the long pathway that led from chemicals in space, to Earth’s formation, to pre-life chemistry on the planet, to early protocells, and finally to advanced cells with metabolism and protein synthesis. Sprawling explorations like these require expertise in many fields, including chemistry and biochemistry, geology and geophysics, and astronomy.

Szostak (pronounced SHAH-stak) may be the ideal person to pursue answers. A Nobel laureate, professor of genetics at Harvard Medical School, professor of chemistry and chemical biology in the Faculty of Arts and Sciences, the Rich Distinguished Investigator at Massachusetts General Hospital (MGH), and a Howard Hughes Medical Institute investigator, he is described by others as a brilliant, driven scientist. But he’s also known for mild-mannered humility, including a willingness to dive deeply into subjects that are new to him, and for his collegiality, for helping to foster idea-sharing that is moving science forward.

His own research focuses on one segment of the pathway to life: the protocell, “a really, really simple primordial cell that could assemble from chemicals that were around early on, on the surface of Earth,” Szostak explains. He hopes to understand how it would grow and divide and start to replicate, and eventually evolve. “We may not know what actually happened, but maybe we can work out different possible paths,” he says. “All we can do is try to assemble things in the lab that seem plausible.”

More here.