Multicellular Life Started Far Earlier Than Thought: Fossil Evidence
Experts recently stumbled upon a fossil of what may be the oldest multicellular organism ever seen. A recent study of the fossil has revealed that it is about 60 million years older than when it was believed the first multicellular organisms started to crawl out of the Earth's primordial sludge, implying that the textbooks are due for a pretty serious rewrite.
The study, which was recently published in the journal Nature, details how a fossil boasting evidence of complex multicellularity has been dated to be about 600 million years old. That's 60 million years before complex animals are thought to have appeared during the Cambrian Explosion.
"This opens up a new door for us to shine some light on the timing and evolutionary steps that were taken by multicellular organisms that would eventually go on to dominate the Earth in a very visible way," Shuhai Xiao, a professor of geobiology in the Virginia Tech College of Science, said in a recent release.
"Fossils similar to these have been interpreted as bacteria, single-cell eukaryotes, algae, and transitional forms related to modern animals such as sponges, sea anemones, or bilaterally symmetrical animals. This paper lets us put aside some of those interpretations."
According to Xiao, this isn't the first multicellular fossil from so long ago, but its remarkable clarity and preservation allowed for experts to come to some very concrete conclusions.
The fossil and others like it, unearthed in the central Guizhou Province of South China, showed signs of cell-to-cell adhesion, differentiation, and programmed cell death - qualities of complex multicellular eukaryotes such as animals and plants. It had been previously thought that these characteristics had started to develop much later in the timeline prior to the Cambrian Explosion.
Still, Xiao and his collaborators add that you shouldn't throw away your biology texts just yet. While some hypotheses can be disproven with the existence of these fossils, they may represent a very specific niche far ahead of their time - possibly the predecessors of multicelluar algae, and not more iconic life.