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Scientists Find 'Oldest Human Ancestor' -- A Big-Mouthed Sea Creature With No Anus (bbc.com)
An anonymous reader quotes a report from BBC: Researchers have discovered the earliest known ancestor of humans -- along with a vast range of other species. They say that fossilized traces of the 540-million-year-old creature are "exquisitely well preserved." The microscopic sea animal is the earliest known step on the evolutionary path that led to fish and -- eventually -- to humans. Details of the discovery from central China appear in Nature journal. The research team says that Saccorhytus is the most primitive example of a category of animals called "deuterostomes" which are common ancestors of a broad range of species, including vertebrates (backboned animals). Saccorhytus was about a millimeter in size, and is thought to have lived between grains of sand on the sea bed. The researchers were unable to find any evidence that the animal had an anus, which suggests that it consumed food and excreted from the same orifice. The study was carried out by an international team of researchers, from the UK, China and Germany. Among them was Prof Simon Conway Morris, from the University of Cambridge. The study suggests that its body was symmetrical, which is a characteristic inherited by many of its evolutionary descendants, including humans. Saccorhytus was also covered with a thin, relatively flexible skin and muscles, leading the researchers to conclude that it moved by contracting its muscles and got around by wriggling. The researchers say that its most striking feature is its large mouth, relative to the rest of its body. They say that it probably ate by engulfing food particles, or even other creatures. Also interesting are the conical structures on its body. These, the scientists suggest, might have allowed the water that it swallowed to escape and so might have been a very early version of gills.
The evidence for why some people talk out of their anus.
My ism, it's full of beliefs.
I know this comes later in evolution, but doesn't the first orifice for the anus, and the second the mouth in a deuterostome? I realize this creature has only one opening, so it uses it for both. If so, it shouldn't be called a "big mouthed sea creature with no anus" but a "big anus sea creature with no mouth."
A gaping mouth and a weird posterior...
AND NOT A SINGLE MOM JOKE ANYWHERE?
Internet, I am disappoint.
"Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson
Have gnu, will travel.
So far, jfdavis668 is the only person to make a sensible comment. (As opposed to some lame, obvious, snarky, schoolboy type joke.)
I was thinking about that deuterostome angle myself. I wondered if this critter was supposed to be before the deuterostome/protostome split. But they explicitly say in the article that it is a deuterostome. Well, the article didn't say there was no anus, just that they hadn't found one (yet).
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In theory, theory and practice are the same; in practice they're different. (Yogi Berra & A. Einstein)
News flash: assholes exist across the political spectrum. No matter what side you're on, rise above them.
That is all.
If it weren't for deadlines, nothing would be late.
At level 2 and above, I saw 22 comments, only three of which were serious. The comments by jfdavis668 and associated replies.
If this continues, I will just stay off the site.
I thought that the "embryo development parallels/replays evolution" thing was a myth? So the anus forming first in the embryo has nothing to do with when it first evolved.
(This shouldn't be confused with studying similarities in embryo development to infer evolutionary relationships.)
"Earliest ancestor" is a bit of scientific short hand. In long form it means "the fossil we've found is related to and a lot like we expect the earliest ancestor to appear." The odds of any fossil we find actually being that of a direct ancestor of any extant population is pretty small, but it isn't a vast leap to state that seeing that this earliest known deuterostome was hanging out in the sand 500-odd million years ago, it was likely representative of the earliest members of the superphylum, and the actual common ancestor to all extant deuterostomes would have looked a lot like it.
The world's burning. Moped Jesus spotted on I50. Details at 11.
It certainly had to be from a time before politicians if they couldn't find an asshole.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Looks like his detractors are fare more triggered than his supporters.
Look at your pet platypus or echidna and you'll see that they exude milk from modified patches of sweat glands, which is then lapped up from the skin by the infant. Breasts (with internal milk channels leading to one nipple per breast) developed after the ancestors of the monotremes diverged from the ancestors of the marsupials and the placentals.
Or were you being facetious?
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"