Six Ancient Human Species and the Complex Tree of Our Ancestry

This video challenges the linear march of human evolution and presents a branching, interconnected history. It introduces six ancient human species—Neanderthals, Denisovans, Floresiensis, Homo naledi, Homo erectus, and Homo heidelbergensis—and explains how fossil finds and especially ancient DNA reveal interbreeding and shared traits across populations. From early fire mastery to island dwarfism, the story shows that our modern DNA carries echoes of multiple experiments in being human, many of which persisted long before Homo sapiens emerged as the sole survivor.

Overview

New Scientist invites viewers to rethink human evolution as a diversification process rather than a straight line from ape to modern human. The film traces the rise and fall of multiple ancient human species that coexisted with Homo sapiens in different times and places, and it highlights how fossil evidence and genome data reveal interbreeding and shared traits across species.

Nonlinear Ancestry and the Golden Age of Paleoanthropology

The narrative begins with the discovery of human fossils that challenged the view of a single human line. It covers the two golden ages of paleoanthropology, the puzzles surrounding early finds such as Dubois’ Homo erectus and the Neanderthal skull in the Neander Valley, and the shift from a dogmatic to a more nuanced understanding of our family tree.

Key Species and Their Relationships

The core of the program introduces six ancient human species that once roamed the Earth alongside Homo sapiens. Neanderthals and Denisovans are presented as our closest relatives with large brains and complex behavior. Floresiensis, the Hobbit, on Flores Island, challenges assumptions about brain size and tool use. Homo naledi from South Africa shows a mix of primitive and derived features with evidence suggesting potential symbolic behavior. Homo erectus is highlighted as an early upright-walking lineage that may have sparked major innovations like fire and hand axes. Homo Heidelbergensis is described as a bridge between erectus and later humans, potentially giving rise to both Neanderthals and us.

Interbreeding and Shared DNA

The film emphasizes that interbreeding occurred between Homo sapiens and Neanderthals and Denisovans, leaving living traces in many today. It explains how certain DNA segments influence immune function and high-altitude adaptation, illustrating the ongoing relevance of ancient ancestry to modern humans.

What We Still Do Not Know

Despite the wealth of discoveries, many questions remain. The fate of several lineages, the exact appearance of Denisovans, and the possibility of other undiscovered relatives remain topics of debate. The video ends with a sense of discovery still to come as new sites and DNA techniques shed more light on the extended human family.