Bizarre Worm Species Without a Brain or Anus May Be Our Earliest Ancestor

Wednesday, 27 December 2017 - 12:42PM
Weird Science
Earth
Wednesday, 27 December 2017 - 12:42PM
Bizarre Worm Species Without a Brain or Anus May Be Our Earliest Ancestor
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Image Credit: University of Tsukuba
When people imagine humanity's earliest ancestors, they probably think of a hairy ape-human hybrid, or maybe a furry little mammal that looks like a possum. What they do not imagine is a tiny, flat slab of a worm that has no heart, central nervous system, or anus. But that may be the truth.

Scientists recently discovered a new species of marine worm, which they have dubbed xenoturbella japonica, that may be the ancestor to the rest of the xenoturbella family, a type of extremely simple worm that was among the first creatures to appear ahead of the so-called Cambrian Explosion, the period of history where all kinds of new lifeforms developed. If humans exist at the end of a very long branch in the tree of life, these tiny, weird little worms are close to the root—meaning that they may be our extremely distant progenitors.

via GIPHY


According to Newsweek:

Opening quote
The researchers make particular note of how the creature might fit on the evolutionary tree. There are several species of Xenoturbella already known to science, which fit into "shallow" or "deep" subgroups. But this new species shares traits from both groups. Therefore, X. japonica 's unique features might mean that it's an even more primitive, ancestral form of the the Xenoturbella group.
Closing quote


These worms are only a few centimeters long, and usually live in the deep part of the ocean, but X. japonica was found close to a marine research station. Though scientists are still investigating its biology, the lack of so many supposedly crucial organs (like, you know, a reproductive system) proves that life can take strange and alien forms even here on Earth. Research into the development of these worms may shed light not only on how life evolved on Earth, but how it might evolve on other planets.

Here's a short video that gives more details about the worm (feel free to mute the speech-to-text narration):



Don't let X. japonica's resemblance to a fluke worm freak you out—they're a totally different animal, which means there's definitely not a branch of the evolutionary tree that ends with the terrifying Flukeman from X-Files.

via GIPHY

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Scientists Discover Ancient Worm Species That Survives Without Brain Or Anus
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