Despite decades of research, how life began on Earth remains one of the most challenging scientific conundrums facing modern science.

Or here is Paul Davies’s colleague and co-author Sara Imari Walker resorting to hope and luck:

The origins of life stands among the great open scientific questions of our time. While a number of proposals exist for possible starting points in the pathway from non-living to living matter, these have so far not achieved states of complexity that are anywhere near that of even the simplest living systems. A key challenge is identifying the properties of living matter that might distinguish living and non-living physical systems such that we might build new life in the lab. This review is geared towards covering major viewpoints on the origin of life for those new to the origin of life field, with a forward look towards considering what it might take for a physical theory that universally explains the phenomenon of life to arise from the seemingly disconnected array of ideas proposed thus far. The hope is that a theory akin to our other theories in fundamental physics might one day emerge to explain the phenomenon of life, and in turn finally permit solving its origins….If we are so lucky as to stumble on new fundamental understanding of life that allows us to solve our origins, it could be such a radical departure from what we know now that it might be left to the next generation of physicists to reconcile the unification of life with other domains of physics, as we are now struggling to accomplish with unifying general relativity and quantum theory a century after those theories were first developed. [Emphasis added.]

But “hope” is not a good science strategy.

As science writer Alex Berezow puts it a bit more bluntly:

The origin of life is a profound mystery. Once life arose, natural selection and evolution took over, but the question of how a mixture of various gases created life-giving molecules that arranged into structures capable of reproducing themselves remains unanswered. Many theories have been proposed, some of which are popular (e.g., RNA World), and some of which are a far-fetched (e.g., aliens). Unlike politics, more ideas are not necessarily better; in science, a diversity of theories tends to betray the reality that scientists have no idea what’s going on.

One sign of the problem here is the proliferation of hypotheses, indicating the lack of any good solution.

Cross-posted at Darwin’s God.

Photo credit: U.S. Department of Agriculture [CC BY 2.0 or Public domain], via Wikimedia Commons