Seaweed-like fossils discovered in China is dividing the scientific community about the evolution of complex life on Earth.
Through the newly discovered fossil, some researchers claim that the evolution of complex life may have occurred a billion years earlier than previously believed. However, those who disagree, argue that evidence is still lacking.
History Of Earth's Complex Life
Life is believed to have existed from the primordial soup, after which all things remained single-celled and very basic. The situation was like that for billions of years, with some scientists even calling it "boring billion" as life seems to have halted during that time.
Through time, these cells found a way to converge and become eukaryotes or organisms with complex cells. In the past, these organisms appear in fossils that date back to only approximately 600 million years ago. This is also the time when multiple soft-bodied creatures emerged from the oceans.
The changes pave the way for the occurrence of all other plants and animals that existed on Earth.
Over the years, the topic of interest of many scientists have been to determine when exactly eukaryotes developed.
New Discovery
The new fossils that sparked a new debate was unearthed in Hebei province, China. The team found 167 calculable fossils, with the biggest measuring 30 x 8 centimeters (12 x 3 inches). About a third of these fossil exhibits only one of the four regular shapes, signifying its complex feature.
Combining these findings creates a significant proof for the early evolution of complex life on Earth, says corresponding author Maoyan Zhu.
"This totally renews current knowledge on the early history of life," she adds.
Scientific Community Divides
The team strongly believes their discovery can spark a reasonable discussion in the scientific community, with University of Bristol's Phil Donoghue even calling it a "big deal." According to him, although the fossils are not the oldest in history, they are still among the oldest multiple-celled eukaryote.
The existence of the organisms that dates back to 1.5 billion years ago means that the amounts of oxygen during that time were adequate to support such complex organisms.
Despite these, not all scientists are convinced.
For Jonathan Antcliffe from the University of Oxford, there is no evidence pointing to the fossils as eukaryotes, as opposed to bacterial, which are single-celled and do not contain genetic material. Instead, he thinks that the fossils were groups of bacterial cells rather than a single organism with complex cells.
Adding to the doubt, the study's degree of detail is not enough to tell whether the organisms are simple or complex, according to Abderrazak El Albani of France's University of Poitiers.
The study was published in the journal Nature Communications on May 17.
