4 ms·

One fact that still blows my mind is that into the 1990's, there were something like 12,000 known prokaryotic species, and microbiologists estimated anywhere fr

One fact that still blows my mind is that into the 1990's, there were something like 12,000 known prokaryotic species, and microbiologists estimated anywhere from 100,000 to a million were still undiscovered, since they didn't like to grow in a Petri dish. But with the advent of PCR based techniques, that number grew to one trillion. Not only whole new phyla but two entire new branches of life (DPANN and CPR) were discovered in the early 2000's gold rush, and microbiology and mycology are still struggling with how to classify and organize these organisms, along with foundational questions like what 'known species' even means. It's a pretty cool time to follow those fields. tl;dr we failed to notice 99.999% of life on Earth until about twenty years ago.

random_ind_dude 4y ago
> A recent estimate of the global number of prokaryotic species is 2.2–4.3 million [110], down from previous potentially flawed estimates of trillions [111] From this Nature article: https://www.nature.com/articles/s41396-021-00941-x https://www.nature.com/articles/s41396-021-00941-x
- idlewords 4y ago
  See the cited paper by Locey and Lennon (https://doi.org/10.1186/s13062-020-00261-8 https://doi.org/10.1186/s13062-020-00261-8) for a counterargument. The issue comes down to mathematical modeling of biodiversity and microbiologists are fighting about it. The fact that dozens of new phyla and two entire branches of life were discovered in the past 20 years is not disputed by either side. A good backgrounder on this topic is "Assessing the global phylum level diversity within the bacterial domain: A review", https://doi.org/10.1016/j.jare.2014.10.005 https://doi.org/10.1016/j.jare.2014.10.005
dejj 4y ago
TIL a salt water spring at -5C temperature exists (and extremophiles live in it): https://en.wikipedia.org/wiki/Axel_Heiberg_Island#Lost_Hammer_Spring https://en.wikipedia.org/wiki/Axel_Heiberg_Island#Lost_Hamme...
filoeleven 4y ago
Fascinating! Is the way these new groups mess with their genetics different enough from the rest of Earth’s life to require another shift in how we classify them? “What ‘known species’ even means” points to maybe yes, but I’m not versed in genetics and just found out about these groups from your post. It’s only been, what, 20 or 30 years since our ability to look at genes started really shaking up taxonomy and yielded “the phylogenetic tree.” I wonder what studying these tiny weirdos will teach us about what we still don’t know about our own more stable branches.
- idlewords 4y ago
  One of the groups (DPANN) is I believe invariably symbiotic, which made it hard to find through traditional methods. It may shed light on how eukaryotes got started. A kind of fascinating problem in microbiology is that prokaryotes didn't take high school science and don't realize you can't acquire traits, you can only inherit them. So they trade genetic material with each other like Pokemon cards in a process called "horizontal gene transfer". This makes it considerably harder to figure out what 'species' even means.

random_ind_dude 4y ago

> A recent estimate of the global number of prokaryotic species is 2.2–4.3 million [110], down from previous potentially flawed estimates of trillions [111] From this Nature article: https://www.nature.com/articles/s41396-021-00941-x https://www.nature.com/articles/s41396-021-00941-x

idlewords 4y ago
See the cited paper by Locey and Lennon (https://doi.org/10.1186/s13062-020-00261-8 https://doi.org/10.1186/s13062-020-00261-8) for a counterargument. The issue comes down to mathematical modeling of biodiversity and microbiologists are fighting about it. The fact that dozens of new phyla and two entire branches of life were discovered in the past 20 years is not disputed by either side. A good backgrounder on this topic is "Assessing the global phylum level diversity within the bacterial domain: A review", https://doi.org/10.1016/j.jare.2014.10.005 https://doi.org/10.1016/j.jare.2014.10.005

dejj 4y ago

TIL a salt water spring at -5C temperature exists (and extremophiles live in it): https://en.wikipedia.org/wiki/Axel_Heiberg_Island#Lost_Hammer_Spring https://en.wikipedia.org/wiki/Axel_Heiberg_Island#Lost_Hamme...

filoeleven 4y ago

Fascinating! Is the way these new groups mess with their genetics different enough from the rest of Earth’s life to require another shift in how we classify them? “What ‘known species’ even means” points to maybe yes, but I’m not versed in genetics and just found out about these groups from your post. It’s only been, what, 20 or 30 years since our ability to look at genes started really shaking up taxonomy and yielded “the phylogenetic tree.” I wonder what studying these tiny weirdos will teach us about what we still don’t know about our own more stable branches.

idlewords 4y ago
One of the groups (DPANN) is I believe invariably symbiotic, which made it hard to find through traditional methods. It may shed light on how eukaryotes got started. A kind of fascinating problem in microbiology is that prokaryotes didn't take high school science and don't realize you can't acquire traits, you can only inherit them. So they trade genetic material with each other like Pokemon cards in a process called "horizontal gene transfer". This makes it considerably harder to figure out what 'species' even means.