
Scientists Debate the Origin of Cell Types in the First Animals - pseudolus
https://www.quantamagazine.org/scientists-debate-the-origin-of-cell-types-in-the-first-animals-20190717/
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ilamont
This reminded me the research of Jack Szostak, a Nobel Laureate who is looking
back even further to the origins of life itself. Specifically, how the first
protocells formed and reproduced. From an article published this summer
([https://harvardmagazine.com/2019/07/origin-life-
earth](https://harvardmagazine.com/2019/07/origin-life-earth)):

 _He and others believe they can reconstruct in the lab the long pathway that
led from chemicals in space, to Earth’s formation, to pre-life chemistry on
the planet, to early protocells, and finally to advanced cells with metabolism
and protein synthesis._

It goes on to say:

 _Despite some theories that early life arose near hydrothermal vents in the
deep ocean, Szostak is more convinced by research showing that the earliest
cells developed on land in ponds or pools, possibly in volcanically active
regions. Ultraviolet light and lightning strikes could have helped convert
molecules in the atmosphere into cyanide and other useful materials to
generate the building blocks of life. The shallow water would give those
materials a place to accumulate at high concentrations, and volcanic activity
could create hot and cold temperature fluctuations helpful for certain
chemical reactions._

Key elements in the protocell included a fatty membrane for protection and
growth/division, something which his group has been able to demonstrate in the
lab. A bigger challenge is passing along genetic material to the next
generation, which involves complicated RNA replication processes.

Full article: [https://harvardmagazine.com/2019/07/origin-life-
earth](https://harvardmagazine.com/2019/07/origin-life-earth)

------
somethingnot
> _The first complication came in 2008, when a group of scientists, in an
> effort to more precisely map out the evolutionary relationships among
> animals on the tree of life, identified comb jellies rather than sponges as
> the earliest animals._

Interestingly, comb jellies have RGB lights. They were dropped in later
animals, probably many viewed them as too tacky, but nature truly was on to
something:

[https://giphy.com/gifs/closeup-comb-
lobed-13tbkKy93iYuuA](https://giphy.com/gifs/closeup-comb-
lobed-13tbkKy93iYuuA)

[https://media1.giphy.com/media/7ofEYFGlgZehO/giphy.gif](https://media1.giphy.com/media/7ofEYFGlgZehO/giphy.gif)

~~~
AllegedAlec
> The first complication came in 2008, when a group of scientists, in an
> effort to more precisely map out the evolutionary relationships among
> animals on the tree of life, identified comb jellies rather than sponges as
> the earliest animals

I really hate this wording, because it gives the wrong idea, namely that Comb
Jellies as they exist now are the same as they existed 600-700 million years
ago.

