The earliest ancestors of humans can be traced back to a group of primates known as hominids or hominins. These ancient hominins diverged from the evolutionary lineage of other primates around 6 to 7 million years ago. While the exact identification and classification of early hominins is an ongoing field of research with new discoveries and findings, some of the key species that are considered among our earliest ancestors include Australopithecus afarensis, Sahelanthropus tchadensis, Homo erectus, and more.
But what if we were forced to understand our first ancestors in a different way than before? A new discovery coming from Australia seems to point to such a scenario.
The Protosterol Biota microscopic creatures change the rules of the game
Aljazeera reveals that a new extraordinary discovery took place in ancient rocks from northern Australia, where a “lost world” of microscopic organisms was unearthed that could revolutionize our understanding of humanity’s earliest ancestors. Known as Protosterol Biota, these eukaryotic creatures lived in Earth’s waterways roughly 1.6 billion years ago.
Eukaryotes possess a complex cellular structure with mitochondria and a nucleus. The newly discovered organisms are believed to be even older than the last eukaryotic common ancestors (LECA), potentially representing the oldest remnants of our own lineage. These creatures likely played a vital role in shaping marine ecosystems throughout Earth’s history and may have been early predators, consuming bacteria.
The discovery came after a decade of research by an international team and provides unique insights into early life and ecology and sheds light on a previously unknown chapter in our evolutionary past.
ANU’s Jochen Brocks, who’s one of the scientists responsible for the discovery, explained:
The Tonian Transformation is one of the most profound ecological turning points in our planet’s history,
Just as the dinosaurs had to go extinct so that our mammal ancestors could become large and abundant, perhaps the Protosterol Biota had to disappear a billion years earlier to make space for modern eukaryotes.
The earliest human ancestors, which are often referred to as hominins, shared several common characteristics. These traits set them apart from other primates and laid the foundation for the evolution of modern humans. Some key features shared by our earliest human ancestors include increased brain size, bipedalism, social behavior, and tool use.