About the science

Three domains, and what we now know

The atlas uses the traditional three domains, Bacteria, Archaea and Eukaryotes, as entry points because they are how most people learn biology. They are a teaching framework.

Modern genome studies show that eukaryotes, the cells with a nucleus that make up all animals, plants and fungi, grew out of the archaea, close to a group called the Asgard archaea. The tree draws them that way: the eukaryote branch leaves the archaeal limb rather than splitting three ways at the root.

At the base is LUCA, the last universal common ancestor. It is the most recent population that everything alive descends from, not the first life on Earth. Other early lineages likely lived alongside it and left no descendants.

Evolution branches. No living group is “more evolved” than another; humans are one small, recent twig among millions.

Dates and certainty

Split dates are rounded, mainstream estimates in millions of years ago. Many, especially for early microbes, carry large uncertainties; groups marked as debated show a note in their profile. The 3D layout is drawn to look like a living tree: it keeps every parent-child relationship exact, but a branch's height on screen is not a measure of time. The tagline's 3.8 billion years follows the long-standing figure for early evidence of life; one 2024 study places LUCA around 4.2 billion years ago.

Colours are navigation aids only: cyan for bacteria, violet for archaea, emerald for eukaryotes, amber for whatever you select.

Images

Version 1 shows no photographs. Images will be added only with clear licences and visible credit for each one.