Post by Pro Plydhttps://www.sciencedaily.com/releases/2024/10/241003123543.htm
Pockets of microbes have been found living within
a sealed fracture in 2-billion-year-old rock. The
rock was excavated from the Bushveld Igneous
Complex in South Africa, an area known for its
rich ore deposits. This is the oldest example of
living microbes being found within ancient rock so
far discovered. The team involved in the study built
on its previous work to perfect a technique involving
three types of imaging -- infrared spectroscopy,
electron microscopy and fluorescent microscopy --
to confirm that the microbes were indigenous to the
ancient core sample and not caused by contamination
during the retrieval and study process. Research on
these microbes could help us better understand the
very early evolution of life, as well as the search
for extraterrestrial life in similarly aged rock
samples brought back from Mars.
I posted on this Oct 4th, but it never showed up.
Repost:
https://www.sciencedaily.com/releases/2024/10/241003123543.htm
The claim is that these bacteria may have been trapped in the rock
fractures for a very long time. They could represent some ancient
lineages of bacteria. The last paper on the common ancestor of all life
speculated that this common ancestor evolved after chemotrophes these
chemotrophes likely evolved the genetic code that the common ancestor of
extant lifeforms inherited from those ancestors.
https://www.nature.com/articles/s41559-024-02461-1
This paper indicates that our LUCA evolved after the genetic code had
evolved. The LUCA may not have been a chemotrophe. Both Archaea and
eubacteria have some basic components of photosynthesis, but both also
have existing chemotrophic lineages. The issue probably is how much
horizontal gene transfer has occurred.
If you look at Figure 1 the data indicates that around a billion years
after the LUCA evolved only two lineages derived from LUCA survived to
proliferate. Something severely restricted life on this planet at that
time, and probably most lineages of life didn't make it.
If the bacteria trapped in the old rock have existed as chemotrophes for
billions of years they may represent lineages that might add to what we
currently have.
An alternative that Nyikos may have liked is that space aliens or a
comet or asteroid may have seeded Archaea and eubacteria onto this
planet 3.2 billion years ago, and those two lineages had evolved on the
alien planet a billion years before they came to earth.
Ron Okimoto