TORONTO -- Researchers at the University of California Riverside (UCR) have drawn a direct connection between Earth’s earliest multicellular organisms – some without heads – and modern-day humans.
The study, published in the journal “Proceedings of the Royal Society B,” says that 555-million-year-old oceanic creatures from the Ediacaran period share genes with humans and animals from today.
"None of them had heads or skeletons. Many of them probably looked like three-dimensional bathmats on the sea floor, round discs that stuck up,” said Mary Droser, a geology professor at UCR in a press release. “These animals are so weird and so different, it’s difficult to assign them to modern categories of living organisms just by looking at them, and it’s not like we can extract their DNA — we can’t.”
Instead, researchers studied preserved fossil records to link the ancient animals’ appearance and behaviours to genetic analysis of currently living things. They chose four animals researchers considered representative of the more than 40 recognized species from the Ediacaran period. Some were no larger than a few millimeters.
Sea-dwelling Kimberella, oval-shaped Dickinsonia, stationary Tribrachidium and Ikaria – a creature the size of a grain of rice -- were the four ancient organisms studied. Most were symmetrical and had a non-centralized nervous system and musculature and could repair damaged body parts through a process known as “apoptosis,” the release states.
The genes involved in the process of apoptosis are also “key elements of human immune systems.”
“The fact that we can say these genes were operating in something that’s been extinct for half a billion years is fascinating to me,” said lead study author and paleontologist Scott Evans.
In the future the UCR research team plans to investigate muscle development to understand early animal evolution.
