Our species, Homo sapiens, evolved in Africa. Yet, understanding why we evolved, from whom, and how our evolution was shaped by climate and environmental change remains elusive.
The oldest fossils that have unique features present in all modern humans are found in Africa between 300,000 and 200,000 years ago, which also corresponds to the period when genetic data indicates all living humans last shared a common ancestor. But we also know that the long-standing ‘Out of Africa model’ as originally formulated no longer holds. To understand our origins we need to go beyond the time when our species had already evolved – back through time to 700,000 years ago, when our lineage was evolving independently from that of the Neanderthals, and even beyond that time, when the ancestral population we share with Neanderthals had begun its evolutionary trajectory separate from other hominins. We know amazingly little about human evolution then - fossils of this age in Africa are very rare, those that exist are strikingly different from each other, and determining their age with certainty is extremely challenging. Yet, it is only by trying to build our evolutionary archive in Africa for the last million years that we will understand how our origins are linked to the major climate and environmental shifts that took place then, and how our own evolution impacted the ecosystems on which we depend.
Contributing to this understanding is the core aim of the Ngipalajem project – to find new hominin fossils, contextualise them ecologically and chronologically, and through their study, fill some of the missing pages in our story.
To do this, we work in Turkana in northern Kenya, where dozens of hominin fossils from 4 to 1.3 million years have been found, as well as two of the earliest known modern humans in the world, dating to ~230,000 years ago. Since palaeontological work in Turkana began in the late 1960s, scientists thought that sediments (and thus fossils) of the last million years were not preserved. Our work has shown this is not the case – not only sediments of this age do exist, but are also rich in fossils, including hominins. Our project is discovering new fossils from this critical period in time – of both hominins and fauna, establishing their geochronological framework, and through their study, attempting to provide new insights into our evolutionary past.
