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The article states that the fossil was "an animal", without further explaining what actually constitutes "an animal", or what characteristics made it unique co
by stareatgoats 8y ago
The article states that the fossil was "an animal", without further explaining what actually constitutes "an animal", or what characteristics made it unique compared to other organisms at the time (or now for that matter). Maybe it's evident to people in the field, to a layman (like me) the term 'animal' is fairly fuzzy.
I went to Wikipedia and found this definition: "With few exceptions, animals consume organic material, breathe oxygen, are able to move, reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development".
So these 'Ediacarans' fall into this category?
- ajross 8y agoThey mean "an animal" in the cladographic sense as being part of the same evolutionary tree as modern animals, and not e.g. lichens or funguses. Specifically, they seem to have detected cholesterol (or some decay product thereof maybe) in the fossil, which is a lipid that only animals make. The identity of the ediacaran fauna has long been controversial. They don't "look like" modern animals (all of whom descend from forms that appeared later, in the cambrian explosion), so they're hard to place. This is a big, big result if it holds up. FWIW: this is the Wikipedia article you want to be reading: https://en.wikipedia.org/wiki/Ediacaran_biota https://en.wikipedia.org/wiki/Ediacaran_biota
- deleted 8y ago[deleted]
- gwern 8y agoLowe explains it a bit more: http://blogs.sciencemag.org/pipeline/archives/2018/09/21/sitting-there-for-five-hundred-million-years http://blogs.sciencemag.org/pipeline/archives/2018/09/21/sit...
- jasonlotito 8y ago> Now, by identifying the remains of organic matter on newly discovered Ediacaran fossils as ancient cholesterol, the scientists have been able to confirm Dickinsonia was an animal, which makes it the oldest known animal.