Billions of years ago, #life crossed a threshold. Single cells started to band together, and a world of formless, unicellular life was on course to evolve into the riot of shapes and functions of multicellular life today, from ants to pear trees to people.

It's a transition as momentous as any in the history of life, and until recently we had no idea how it happened.

But the momentous transition to #multicellular life may not have been so hard after all.

The evidence comes from multiple directions. The evolutionary histories of some groups of organisms record repeated transitions from single-celled to multicellular forms, suggesting the hurdles could not have been so high.

Genetic comparisons between simple multicellular organisms and their single-celled relatives have revealed that much of the molecular equipment needed for cells to band together and coordinate their activities may have been in place well before multicellularity evolved.

And clever experiments have shown that in the test tube, single-celled life can evolve the beginnings of multicellularity in just a few hundred generations—an evolutionary instant.

#biology #evolution
https://www.science.org/content/article/momentous-transition-multicellular-life-may-not-have-been-so-hard-after-all

The afternoon of the eighth day of the Konstanz School of Collective Behaviour 2025 (#KSCB2025) is devoted to a #keynote by Naama Brenner on #biophysics of #cells, either in #unicellular or #multicellular #organisms

@cbehav.bsky.social

https://www.exc.uni-konstanz.de/kscb/

Prototaxites represents the first giant organisms to live on the terrestrial surface, reaching sizes of 8 metres in the Early Devonian.

It was an extinct lineage of #multicellular terrestrial #eukaryotes.

Assignments to groups of multicellular algae or land plants have been repeatedly ruled out leaving two major alternatives: #Prototaxites was either a #fungus or a now entirely extinct lineage.

The latter hypothesis seems more plausible based on nrw evidence.

https://astrobiology.com/2025/03/ancient-prototaxites-dont-belong-to-any-living-lineage-possibly-a-distinct-branch-of-multicellular-earth-life.html

Once upon a time, long ago, the world was encased in #ice. Hundreds of millions of years ago, glaciers and sea ice covered the globe. The most extreme scenarios suggest a layer of ice several meters thick even at the equator.

But when seawater gets cold, it gets viscous.

This fact could explain how single-celled ocean creatures became #multicellular when the planet was frozen during “Snowball Earth,” according to experiments.

#evolution #biology https://www.quantamagazine.org/the-physics-of-cold-water-may-have-jump-started-complex-life-20240724/