The oddest fact about your own cells is that they are, in part, immigrants. Every animal, plant and fungus is built from cells that carry mitochondria, the small compartments that burn fuel for energy. The standard account in biology is that mitochondria began as free-living bacteria and ended up living inside a larger host cell. That one merger is a big part of why complex life exists at all.

The trouble is that it happened once, billions of years ago, and left no diary. Biologists reconstruct it by comparing living things that sit at odd positions on the family tree, hoping some descendant kept a trait from the middle of the story.

That is why the New York Times report of 26 September matters. A scrappy science project, which the Times ties to a motel room, has produced two new species of a rare organism. The Times says the find could elucidate a fundamental transition in the history of life. The rarity is the point. A common organism has been studied for decades. A rare one has barely been looked at, so every new species is a fresh data point on a thinly sampled branch.

The stage here is the earliest one in science: collection and description. Two species have been named. Nothing in the report I have seen says what they reveal about the origin of complex cells, and that claim has not been tested. A new species on a branch near the transition tells you where to look. It does not tell you what you will find.

The next gate is the unglamorous one. Someone has to read the genomes of the two species and compare them with their closest relatives. If the genes say these organisms sit near the transition, the transition story gets a new witness. If they do not, the motel room still produced two new species, which is not nothing.