Revolutions in the biological sciences can take many forms. Sometimes they erupt from the use of a novel tool or the invention of a radical theory that suddenly opens so many new avenues for research, it can feel dizzying. Sometimes they take shape slowly, through the slow accumulation of studies, each one representing years of painstaking work, that collectively chip away at the prevailing wisdom and reveal a stronger, better intellectual framework. Both kinds of revolution unleash avalanches of new ideas and insights that improve our understanding of how life works.

This past year has had no shortage of these. For example, researchers successfully grew “embryo models” — lab-grown artificial embryos that mature like real ones — that reached a more advanced developmental stage than ever before. That accomplishment could eventually yield valuable new insights into how human fetuses grow, although debate about the ethical status of those models seems likely, too. Meanwhile, in the world of neuroscience, researchers studying depression have continued to move away from the theory that has generally guided much of the research and pharmaceutical treatment of that disease for decades.

But those kinds of biological revolution involve human ingenuity, with researchers in the life sciences coming to new realizations. Revolutions also occur in the biology itself — when evolution has enabled organisms to do something unprecedented. Biologists have recently discovered many more instances of this kind of breakthrough.

Keeping track of time, for instance, is a function that’s essential to all living things, from microorganisms biding their time till the next cell division to embryos growing limbs and organs, to more complex critters tracking the passage of day and night. Teams of researchers plugging away in laboratories around the world have recently discovered that some key features of timekeeping are tied to cellular metabolism — which means that the organelle called the mitochondrion is both a generator and a clock. Other aspects of timekeeping are metered by the progress of a molecular ballet in which specialized proteins pirouette together before separating again.

Researchers also hope to soon make important discoveries now that they can culture some of the primitive, long-lost cells called Asgard archaea. A billion years ago, Asgard archaea (or cells much like them) took the outrageous step of forming permanent partnerships with the ancestors of mitochondria, thereby giving birth to the first complex cells. The secrets of how and why that biological breakthrough happened may be lurking in those exotic cell cultures. Meanwhile, other researchers are scrutinizing the “grit crust” microbes that live in the infamously arid Atacama Desert of Chile for clues to how the first land-dwelling cells survived.

Enough marvelous biological innovations were discovered in 2023 to form a veritable parade: plankton that supercharged their photosynthetic abilities by repurposing one of their membranes, and underground microbes that learned to make oxygen in total darkness. An immunological trick that protects babies in the womb, and a neurological trick that lets the brain map out social relationships like physical landscapes. A simple mutation that transformed ants into complex social parasites virtually overnight, and a strategic demolition of DNA that worms use to safeguard their genomes.

Quanta chronicled all those and more this year, and as new breakthroughs in fundamental biology come to light in the years ahead, we will be there for them too.