New Miscellany 2: designing for the future (General)

by David Turell , Saturday, April 05, 2025, 20:42 (1 day, 7 hours, 45 min. ago) @ David Turell

A new discovery about the evolution of bacteria:

https://www.sciencedaily.com/releases/2025/04/250403143647.htm

"Scientists have helped to construct a detailed timeline for bacterial evolution, suggesting some bacteria used oxygen long before evolving the ability to produce it through photosynthesis.

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"'The key innovation was using the GOE as a time boundary, assuming that most aerobic branches of bacteria are unlikely to be older than this event unless fossil or genetic signals suggested otherwise."

"The team first estimated which genes were present in ancestral genomes. They then used machine learning to predict whether or not each ancestor used oxygen to live.

"To best utilise fossil records, the researchers included genes from mitochondria (related to alphaproteobacteria) and chloroplasts (related to cyanobacteria), which allowed them to use data from early complex cells to better estimate when events happened.

"'Results show that at least 3 aerobic lineages appeared before the GOE -- by nearly 900 million years -- suggesting that a capacity for using oxygen evolved well before its widespread accumulation in the atmosphere," Professor Hugenholtz said.

"'Evidence suggests that the earliest aerobic transition occurred around 3.2 billion years ago in the cyanobacterial ancestor, which points to the possibility that aerobic metabolism occurred before the evolution of oxygenic photosynthesis.'"

Comment: Another example of preparatory developments in preparation for a future use, in this case oxygen. Like feathers on dinosaurs, dhw will invent a just-so Darwinian tale to explain it.