DNA

Without a good definition of life, how do we look for it on alien planets? Steven Strogatz speaks with Robert Hazen, a mineralogist and astrobiologist, and Sheref Mansy, a chemist, to learn more.

How did life arise on Earth? Steven Strogatz speaks with the Nobel Prize-winning biologist Jack Szostak and Betül Kaçar, a paleogeneticist and astrobiologist, to explore our best understanding of how we all got here.

Several projects are aiming to bring back mammoths and other species that have vanished from the planet. Whether that’s technically possible is beside the point.

When researchers gave a genetic molecule the ability to replicate, it evolved over time into a complex network of “hosts” and “parasites” that both competed and cooperated to survive.

The immune system protects us from a full spectrum of pathogens, but without balance, it can end up hurting us over time, too. The immunologist Shruti Naik explains how our defenses can turn on us.

Life could use a more expansive genetic code in theory, but new work shows that improving on three-letter codons would be a challenge.

Steven Strogatz explores the mysteries of knots with the mathematicians Colin Adams and Lisa Piccirillo.

The detailed understanding of brains and multicellular bodies reached new heights this year, while the genomes of the COVID-19 virus and various organisms yielded more surprises.

Driven by her fascination with highly repetitive, hard-to-read parts of our DNA, Karen Miga led a coalition of researchers to finish sequencing the human genome after almost two decades.