The emergence and increased prominence of disciplines such as synthetic/systems biology has led to unprecedented integration and collaboration between scientific fields. One such integration led to the formation of the Origins of Life Initiative at Harvard. This inter-disciplinary research program brings together unanticipated combinations of scientists including astronomers, chemists, synthetic and molecular biologists, and geologists devoted to understanding the origins of life on earth.
The Origins of Life Initiative and the Harvard Alumi Association hosted a day long symposium at Harvard’s Science Center, entitled The Future of Life focused on discussing the progress made thus far in answering the most long-standing (and potentially philosophical) of all questions in science – what is life, and how did it begin?
This question is being attacked from all possible angles. Some researchers are taking the reductive and molecular approach by seeing how many genes they can subtract from a cell and still maintain life and replication. Others are seeing the minimal numbers of genes to add onto a blank canvas in order to generate life from scratch. Others still are taking the classical, natural history and geology approach in reading the history recorded in the Earth’s crust for hints of billion-year old events.
The keynote speaker (and visiting scientist with the Origins of Life Initiative), surely a familiar name to all life scientists, J. Craig Venter (he of the first human genome and ocean sampling fame) spoke of his recent discoveries on the diversity of life in the oceans. He and his sea-faring crew of scientists found ~85% unique genome sequence from organisms sampled at 200 mile intervals in the ocean, suggesting that the ocean is not a big bag of watery much as previously thought, but an ecosystem with discrete and contained microenvironments. Venter also described the struggles and triumphs of engineering artificial life, first in generating an artificial bacterial virus, PhiX, and then scaling the process up to make an artificial bacterial genome. In one of the coolest (though sadly, least in-depth) portions of his talk, Venter described a procedure in which his team injected a foreign complete genome into a bacterium. Restriction enzymes expressed by this new genome chewed up the host genome, effectively reprogramming the bacterium to the new genome’s specifications, turning it from one strain of bug into another. Fascinating, and a little scary.
Keynote speaker, J. Craig Venter
Jack Szostak demonstrated self-formation of lipid vesicles and their ability to enclose a self-assembled strand of RNA seeded on a clay particle, certainly reagents and environments present in primordial Earth. George Whitesides told of his lab’s attempts to mimic the chemical conditions of earth Earth and the chemical reactions which may have taken place. George Church gave an update on his lab’s progress toward generating artificial life, beginning with the construction of an artificial, self-replicating ribosome (a vitally important cell component responsible for translating RNA into protein). His lab has now demonstrated the reconstitution and function of a ribosome with an artificial ribosomal RNA. The eventual goals of this work include the generation of a bacterium with a minimal gene set of 151 genes that makes proteins to the scientists’ specifications – built of amino acid building blocks not found in nature (D-amino acids, for those chirally inclined), with the advantage of conferring multi-virus resistance on the clever little beasties.
Jack Szostak and George Church taking questions from the audience
It may be difficult to believe, but there was a common theme to this seeming cacophony of scientific expertise and discovery. The theme was, “We just don’t know.” No one knows how life began – or even how to define ‘life,’ if you want to get all philosophical about it – but it’s a question of such paramount interest and importance that key players in many avenues of scientific research are willing to devote their time and resources to answering it. Underneath it all, it was refreshing to hear a bunch of really smart folks say ‘we don’t know.’ It was humbling and put things in a grandiose perspective. No one knows how we all got to be here, but the researchers in the Origins of Life initiative and beyond are trying to find out.