Recently, evolutionary researchers at UC Riverside discovered the oldest known ancestor of both animals and humans – a 555 million-year-old, worm-like creature in Australia.
Researchers believe that this tiny creature is the first ancestor on the family tree of all living creatures.
According to the Proceedings of the National Academy of Sciences, this ancestral animal, which was named Ikaria Wariootia, has been identified as the earliest bilaterian.
This 2.7 millimeters long creature, just about the size of a grain of rice, has been established by researchers as the oldest ancestors of bilaterian.
This identification is due to the organism having two symmetrical sides and a front and back openings at each end, connected by a gut.
According to scientists, the development of bilateral symmetry was an essential process in the evolution of animal and human life. This process gives organisms the ability to move their body at will while being successful at the organization of their body.
Evolutionary biologists believe that the Ikaria’s age is in sync with their fact on when life on earth began. This period is known as the Ediacaran period.
Experts stated that they could not be more thrilled when they read the content of the new research published in the proceedings of the National Academy of Sciences by the team of geologists from the University of California, Riverside.
Geology Professor, Mary Droser says:
“This is what evolutionary biologists predicted. It’s fascinating that we have found lines up so neatly with their prediction.”
In the previous years, evolutionary biologists had found that the earliest multicellular organisms like algal mats and sponges, collectively known as Ediacaran biota, had variable shapes.
According to them, this group of multicellular organisms holds the most complex and oldest of every multicellular organism. However, they couldn’t pinpoint their relatedness to modern-day animals as they often lacked mouths its guts.
Therefore researchers studying the genetics of modern animals believed that the oldest ancestor of all bilaterians was probably small and straightforward with primary sensory organs for activities. To them, identifying the fossilized remains of such an animal would be difficult.
Bilaterians And The Evolution Tree
Bilaterians are an essential part of the evolutionary tree. Not only do they branch out to develop into the dull diversity of animal life, but their body structure also allowed organisms to move forward purposefully.