Recent findings that made the Fermi paradox more puzzling (and scary)
If we look up into the night sky, we should not expect to see stars but darkness. Stars are readily available resources and all of them should be covered in Dyson spheres.
One explanation is that life is very rare. Yet the following studies suggest that the universe should be teeming with life:
Scientists have observed a single-cell alga evolve in real time into a multicellular organism. The transition took around a year and was caused by the introduction of a predator into the environment. https://www.nature.com/articles/s41598-019-39558-8
De novo evolution of macroscopic multicellularity: "Over...(~3,000 generations), multicellular snowflake yeast evolved macroscopic size, becoming ~2·10^4 times larger (~mm scale) and 10^4-fold more biophysically tough, while remaining clonal." https://www.biorxiv.org/content/10.1101/2021.08.03.454982v1
A study published in Nature Chemistry shows that nearly all the ingredients for a potential forerunner to cellular metabolism could have formed easily from just two simple compounds reacting in water. https://www.quantamagazine.org/new-clues-to-chemical-origins-of-metabolism-at-dawn-of-life-20201012/
Scientists have created 2-deoxyribose (the “D” in DNA) by bombarding simulated meteor ice with UV radiation. This adds to the already extensive list of complex biological compounds that can be formed through astrophysical processes. (Origin of life) https://www.nature.com/articles/s41467-018-07693-x
Red Dwarfs (about 75% of the stars in the Milky Way) Blast Their Superflares out the Poles, Sparing Their Planets From Destruction https://www.universetoday.com/152104/good-news-red-dwarfs-blast-their-superflares-out-the-poles-sparing-their-planets-from-destruction/ [Update: The hunt for habitable planets may have just gotten far more narrow: “The pressure from a class M red dwarf star’s radiation is immense, enough to blow a planet’s atmosphere away,” boding poorly for the “Goldilocks Zone” around such stars (the most common type.) https://www.cnn.com/2022/10/25/world/exoplanets-search-narrowed-scn/index.html]
UV Surface Radiation Should Not Limit the Habitability of Active M Star Systems https://news.cornell.edu/stories/2019/04/study-nearest-exoplanets-could-host-life
A new class of exoplanet very different to our own, but which could support life, has been identified by astronomers https://www.cam.ac.uk/research/news/new-class-of-habitable-exoplanets-are-a-big-step-forward-in-the-search-for-life
The ctenophore’s brain suggests that, if evolution began again, intelligence would re-emerge: “invented neurons, muscles & other specialised tissues, independently from the rest of the animal kingdom, using different starting materials" https://aeon.co/essays/what-the-ctenophore-says-about-the-evolution-of-intelligence
Birds show that something functionally similar to the mammalian cortex independently evolved twice https://aiimpacts.org/primates-vs-birds-is-one-brain-architecture-better-than-the-other/
Photosynthesis could be as old as life itself: "enzymes capable of performing the key process in oxygenic photosynthesis – splitting water into hydrogen and oxygen – could actually have been present in some of the earliest bacteria." https://www.imperial.ac.uk/news/217553/photosynthesis-could-life-itself/
Predator-Prey Behaviour in Self-Replicating Interstellar Probes -- "...we find this solution to Fermi's Paradox does not reduce the probe population sufficiently to be viable." https://arxiv.org/abs/1903.00770
"Half-a-billion-year-old creature challenges theory that animals burst onto the scene in an abrupt event known as the Cambrian explosion." https://www.nature.com/articles/d41586-019-02556-x
Fossil Discoveries Challenge Ideas About Earth’s Start: "If some of the new evidence truly represents impressions of primeval life, then our ancestors may be much older than we thought. Life might have arisen the moment the planet was amenable to it — the moment it cooled enough to hold liquid water." https://getpocket.com/explore/item/fossil-discoveries-challenge-ideas-about-earth-s-start