Deep-sea microbes may
be the missing link in search
for origin of complex life
Let us introduce Thor, Loki, Odin and Heimdall- our microbial ancestors dating back two
billion years. A team at Uppsala University,
Sweden, has discovered several microbes
carrying genes that were previously thought
to be unique to more complex life forms,
including humans.
The single-celled microorganisms, called
archaea, were discovered in aquatic
sediments collected at seven sites around
the world, including hydrothermal vents in the
Arctic Ocean and hot springs in Yellowstone
National Park. The four species in question,
named after Norse gods and known as
‘Asgard archaea’, are as different from one
another as a tree is from a mushroom.
The finding supports a decades-old theory
that complex life first arose when an archaeon
consumed a bacterium, but the bacterium
survived. The resulting arrangement proved
to be beneficial to both, and the two previously
separate organisms evolved into life forms
with cells and complex internal structures,
called eukaryotes. All plants and animals
are eukaryotes.
“The things which we thought made
a eukaryote a eukaryote, [are what] we’re
now finding in these new archaea,” said
researcher Brett Baker. “We’re essentially
rewriting the textbook on basic biology.”
So far, the archaea have only been identified
by piecing their genomes together using
separate bits of gathered genetic material.
The team’s next goal is to grow them in the lab.
“It would be great if we could isolate
or grow Asgard cells, and study them
under the microscope,” said Thijs Ettema,
a researcher who was involved in the project.
“I am convinced that this will reveal more
important clues about how complex cells
evolved. Ultimately, our microbial ancestry
will be uncovered.”MICROBIOLOGY3-6
months
The length of time it took to hatch
a dinosaur egg, a team from Florida
State University has found. This long
incubation period, combined with
the fact that it took around one year
for dinosaurs to mature, could have
contributed to their extinction,
the researchers say.13,045
km
The distance flown by a male Alaskan
sandpiper in just one month in order
to mate with as many females
as possible, as tracked by a team
at the Max Planck Institute for
Ornithology, Germany
Hot springs in
Yellowstone housed
the new speciesNUMBERS35 April 2017 April 2017^29