May 1, 2021 03:10 AM
Scientists find billion-year-old fossil life, 'something which has never been described before'
https://gizmodo.com/scientists-find-bill...1846792843
INTRO: On the shores of a Scottish loch lie geologic deposits dating back a billion years, and within the rocks is evidence of the earliest known non-marine multicellular organism, according to a study published in Current Biology. It’s a fascinating new detail in the story of how animals may have evolved from the soup of early Earth.
A team of microscopists, geologists, palynologists, and paleobiologists excavated and described the fossil microorganism, which they named Bicellum brasieri. It appears to be a member of holozoa, the group of organisms that contains animals and their single-celled relatives, but not fungi. The rock deposit from which the fossil emerged, on the beaches of Loch Torridon in Scotland, has been studied for years; in 2011, a Nature paper by the same team described the assemblages at greater length. The new paper dives into the singular complexity of B. brasieri.
“We have found a primitive spherical organism made up of an arrangement of two distinct cell types, the first step towards a complex multicellular structure,” said Charles Wellman, a paleobiologist at the University of Sheffield, in a university press release, adding that it’s “something which has never been described before in the fossil record.” (MORE)
Weird viral DNA spills secrets to biologists
https://www.nature.com/articles/d41586-021-01157-x
INTRO: ‘Alien’ genomes can be found on Earth. Some viruses that infect bacteria use an alternative genetic alphabet that’s distinct from the code used by nearly all other organisms — and, now, two teams have spelt out how the system works.
More than four decades in the making, the studies show how dozens of these bacteriophages (or just ‘phages’), as they are known, write their genomes using a chemical base called 2-aminoadenine, Z for short, instead of adenine — the A in the As, Ts, Cs and Gs of genetics textbooks.
“Scientists have long dreamed of increasing the diversity of bases. Our work shows that nature has already come up with a way to do that,” write Suwen Zhao, a computational biologist at ShanghaiTech University in China, and her team in a 29 April Science paper, showing how ‘Z-DNA’ is made1. Researchers in France described similar insights in a pair of papers in the same journal2,3.
The work is seminal, says Steven Benner, a synthetic biologist and founder of the Foundation for Applied Molecular Evolution in Alachua, Florida, who compares it to US microbiologist Carl Woese’s discovery of a new branch of single-celled life. “It represents the first discovery of a ‘shadow biosphere’ since Woese identified the Archaea a half century ago.” (MORE)
https://gizmodo.com/scientists-find-bill...1846792843
INTRO: On the shores of a Scottish loch lie geologic deposits dating back a billion years, and within the rocks is evidence of the earliest known non-marine multicellular organism, according to a study published in Current Biology. It’s a fascinating new detail in the story of how animals may have evolved from the soup of early Earth.
A team of microscopists, geologists, palynologists, and paleobiologists excavated and described the fossil microorganism, which they named Bicellum brasieri. It appears to be a member of holozoa, the group of organisms that contains animals and their single-celled relatives, but not fungi. The rock deposit from which the fossil emerged, on the beaches of Loch Torridon in Scotland, has been studied for years; in 2011, a Nature paper by the same team described the assemblages at greater length. The new paper dives into the singular complexity of B. brasieri.
“We have found a primitive spherical organism made up of an arrangement of two distinct cell types, the first step towards a complex multicellular structure,” said Charles Wellman, a paleobiologist at the University of Sheffield, in a university press release, adding that it’s “something which has never been described before in the fossil record.” (MORE)
Weird viral DNA spills secrets to biologists
https://www.nature.com/articles/d41586-021-01157-x
INTRO: ‘Alien’ genomes can be found on Earth. Some viruses that infect bacteria use an alternative genetic alphabet that’s distinct from the code used by nearly all other organisms — and, now, two teams have spelt out how the system works.
More than four decades in the making, the studies show how dozens of these bacteriophages (or just ‘phages’), as they are known, write their genomes using a chemical base called 2-aminoadenine, Z for short, instead of adenine — the A in the As, Ts, Cs and Gs of genetics textbooks.
“Scientists have long dreamed of increasing the diversity of bases. Our work shows that nature has already come up with a way to do that,” write Suwen Zhao, a computational biologist at ShanghaiTech University in China, and her team in a 29 April Science paper, showing how ‘Z-DNA’ is made1. Researchers in France described similar insights in a pair of papers in the same journal2,3.
The work is seminal, says Steven Benner, a synthetic biologist and founder of the Foundation for Applied Molecular Evolution in Alachua, Florida, who compares it to US microbiologist Carl Woese’s discovery of a new branch of single-celled life. “It represents the first discovery of a ‘shadow biosphere’ since Woese identified the Archaea a half century ago.” (MORE)