Image courtesy of Stephen Hudson, CC BY-SA 3.0.
Joel Kontinen
Today, oxygen fuels much of life on Earth,
but it wasn't always that way. Three billion years ago, this
gas was scarce in the atmosphere andoceans.
Knowing why oxygen became plentiful could
illuminate the evolution of our planet's flora and fauna, but scientists have
struggled to find an explanation satisfying to all.
Now, a research team has proposed a novel link between
how fast our planet spun on its axis—which defines the length of a day—and the
ancient production of additional oxygen.
Their modelling of Earth's early days, which
incorporates evidence from microbial mats coating the bottom of a shallow,
sunlit sinkhole in Lake Huron, produced a surprising conclusion: As
Earth's spin slowed and led to longer days, that could have triggered more photosynthesis from similar mats, allowing oxygen to build up in ancient seas
and diffuse up into the atmosphere.
Source:
Pennisi, Elizabeth. 2021. Longer days on early Earth set
stage for complex life, Science 373, 6555, pp. 607-608.
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