Strange worm reveals the evolution of digestion

Strange worm reveals the evolution of digestion
Credit: Rald Janssen

A Swedish–Norwegian research team shows in a new study that the intestines of the peculiar Penis worm develop in the same way as those in humans, fish and starfish. This surprising discovery shows that stomachs of very different species are formed in the same way.

The study has been conducted in cooperation between Uppsala University and Sars International Centre for Marine Molecular Biology, Norway, and has just been published in the highly-regarded journal . Studies of the, to a large extent unknown, Penis worm were initiated by professor Graham Budd at Uppsala University a couple of years ago. In the current study the scientists looked at which genes are expressed during the development of , stomach and anus in worm .

What surprised the researchers was not just that the development was the same in the worms as in humans, fish and frogs, but that exactly the same genes were involved in the process.

'This means that the origin of the human stomach is further back in time than previously thought, probably about 500 million years', says Ralf Janssen, postdoc in professor Graham Budd's research group on at Uppsala University.

The study is the first to describe the whole in these strange worms, which have changed very little since the . They are considered to be among the very first bilaterally symmetrical animals in the history of the earth. These animals have a left side and a right side, and today make up 99 per cent of all living animals.

Historically they were divided into two groups based on differences in how the developed in the fetus. This happens at an early stage of fetal development when a few cells move into a part of the fetus called the blastopore. In some animals this later becomes the mouth, in others it develops into the anus. This has long interested scientists around the world.

Penis worms live in shallow parts of the oceans, including off the Swedish west coast where they propagate during the winter.

'There is a huge diversity of unexplored animals in the world's oceans. This study shows that these interesting worms can tell us something important about our origin a dnthat there is certainly more to discover about other organs', says professor Graham Budd.


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Journal information: Current Biology

Provided by Uppsala University
Citation: Strange worm reveals the evolution of digestion (2012, October 26) retrieved 24 October 2019 from https://phys.org/news/2012-10-strange-worm-reveals-evolution-digestion.html
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Oct 26, 2012
This means that the origin of the human stomach is further back in time than previously thought, probably about 500 million years, says Ralf Janssen

Let me see the logic here: Worms, fish and frogs have the same development of certain organs from embyonic stage plus the same genes that are used in human beings.
So where exactly is the connection that human beings somehow developed or inherited anything from the worms, fish or frogs?
The conclusion is unwarranted and unsupported by the real life observation.
One cannot make such an extravagant extrapolation without justification. In this case, there is no way to jump to that conclusion. The logic is flawed, nothwithstanding any other wild assumptions made further down in the article.

Oct 26, 2012
I have a problem with the name. But then, I guess if I were a woman, I'd have a problem if it were called vagina worm.

I could settle for dildo worm. It looks like one, too, more than a penis.

Oct 26, 2012
Kevin is the master of reading short blurbs about complex scientific principles that are targeted to the uneducated masses and making grandiose claims regarding the underlying science that he has absolutely no knowledge of.

Oct 26, 2012
Creationists shouldn't comment on science. It is hilarious to see.

In this case our resident creationist can't stomach that he is a certified distant cousin to a penis worm, while even the traits of the worm knows better. =D

It must be galling to see the facts of having vertebrates flipped on our backs and using the anus for mouth, while invertebrates follows the original evolved pattern. On the other hand, observing creationists it is easy to test what comes out from the mouth is anti-science bullshit made up on the spot.

As is their woo magic, which is the reason they have to trash humanity making progress.

Oct 26, 2012
Creationist logic: 'Let me see the logic here: Stones, sticks and frogs have the same atom nuclei plus the same electrons as human beings. So where exactly is the connection that human beings somehow fall to earth the same as stones, sticks or frogs? The conclusion is unwarranted and unsupported by the real life observation. One cannot make such an extravagant extrapolation without justification. In this case, there is no way to jump to that conclusion. The logic is flawed, nothwithstanding any other wild assumptions made further down in the article.'

Oct 26, 2012
Let me see the logic here:
If only you could.

So where exactly is the connection that human beings somehow developed or inherited anything from the worms, fish or frogs?
The worms, fish, frogs, etc. are not our *ancestors* -- they are our (distant) *cousins*. Common ancestor, y'know: http://en.wikiped..._descent

Oct 26, 2012
Well if Kevin were ever to entertain the idea that we have anything at all in common with worms, he would have to admit that his god does as well, because we humans share his image. And this would be too much for him to bear.

'Damn the evidence! I AM godlike!' He declares, knowing that this is absolutely the only way that he can possibly live forever. 'There are NO VERMIN IN HEAVEN!!!'

Hey keep it down kev you'll wake up the dead.

Oct 27, 2012
Now kevin, if anything could convince you of the common descent of a human from a Penis worm it would be Otto.

Oct 28, 2012
Sad. Only 2.5 inches long. Just like RyggTard.

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