March 2026

Twenty Species and a Partial Skull

Ancient hominid skull on display at a museum. Photo from Unsplash.

By Amit Sen

At least twenty species existed on our side of the split from chimpanzees. Several made tools. Some buried their dead. All of them are gone except us.

Most people, if you asked, would say we earned it. We split the atom and went to the moon. Seven million years of hominins and we are the only ones left. That has to mean something.

The more I read, the less sure I am. Homo sapiens has been around for 300,000 years. The tribe Hominini, seven million. We have been here for a sliver of the chart and we call ourselves special. I think we should wait on that.

Each bar below is one species and its estimated time range. A lot of them overlap. Homo sapiens shared the planet with Neanderthals and Denisovans. We were the last ones here, and it happened more recently than you would think.

Phylogeny

Each bar spans a species' known time range. Hover for details. Dashed lines indicate debated relationships.

Sahelanthropus

Orrorin

Ardipithecus

Australopithecus

Paranthropus

Homo

The chart gives you names and time ranges. It does not tell you what we are working with.

For most of these species, the entire basis for knowing they existed is a few teeth, a jaw fragment, a partial skull. Bones decay and soft tissue disappears in weeks. For every specimen in a museum, millions of individuals lived and died without leaving anything behind.

I keep coming back to the scale. We sit at the right edge of a long chart. For most of our time on it, you could not have picked us out from the species beside us. We were unremarkable for a long time and we have been remarkable for a short one. That might hold up or it might not, and I do not think we know yet.

You have the species. Now trace where they went. You find fossil sites where researchers have dug, and nowhere else, which means the map shows you as much about where people looked as where hominins lived. Gaps on the map are gaps in what we know.

Geography

Now that you know the species, trace where they lived. Step through seven chapters of expansion from a single site in Chad to every continent.

Loading globe...

Homo sapiens is on every continent now. Seven million years of lineage, and we pieced it together from fragments. The record has holes and those holes are permanent. I do not think we know enough yet to say whether we earned our place or stumbled into it. We might be special. The evidence so far is mostly teeth.