MYSTERIES OF THE UNIVERSE
Scientists have begun taking a new approach to discovering the origin of life and are already bridging gaps in our knowledge
We know for certain that life exists. What we don’t know is exactly how life originated on Earth and whether life exists elsewhere. W Yet knowing how basic biological systems came into being would help scientists work out how our world became teeming with plants, insects and animals. It would also assist enormously in the search for extraterrestrial life. “Life is probably the most complex naturally occurring phenomenon in the universe, and the gap between living cells and non-living chemistry is vast,” explains Aaron Goldman, an associate professor of biology at Oberlin College in Ohio. “It’s pretty amazing that life exists at all and fascinating to think about how life, even the simplest life, could have first originated on the early Earth.”
Goldman has made it his mission to work out the best way of learning what life actually is and how it works at the most fundamental level. Such endeavours take into account that life, when it emerged at least 3.8 billion years ago, would have been very different to how it presents itself today. The atmosphere would have been rich in methane and lacking oxygen, with life restricted to microbes lacking specialised cells. “While we haven’t figured out exactly how life originated, the field has developed some pretty good models about what kinds of environments and chemical reactions could have produced precursors to the kinds of biomolecules that are used by life today,” Goldman continues. “At the same time, techniques from evolutionary and computational biology are allowing us to reconstruct the earliest ancestors of very ancient genes and predict with some confidence what molecular functions they might have encoded, leading to a much better understanding of what some of the earliest organisms might have been like.”
One of the decisions faced by scientists trying to decipher how life emerged is which method they should use. On the one hand, researchers can take a top-down approach. This looks at data from life today and works b
