From ScienceDaily:
In an effort to determine how, why, and when multicellularity arose from single-celled ancestors, Xiao and his collaborators looked at phosphorite rocks from the Doushantuo Formation in central Guizhou Province of South China, recovering three-dimensionally preserved multicellular fossils that showed signs of cell-to-cell adhesion, differentiation, and programmed cell death — qualities of complex multicellular eukaryotes such as animals and plants.
The discovery sheds light on how and when solo cells began to cooperate with other cells to make a single, cohesive life form.
The complex multicellularity evident in the fossils is inconsistent with the simpler forms such as bacteria and single-celled life typically expected 600 million years ago.
Actually, we might find multicellulars from earlier eras still. Don’t the comb jellies, far more than merely multicellular, date back to that era? And that pre-Cambrian animal with muscles (560 mya)? Let’s see what else turns up.
Here’s the abstract:
Phosphorites of the Ediacaran Doushantuo Formation (~600 million years old) yield spheroidal microfossils with a palintomic cell cleavage pattern1, 2. These fossils have been variously interpreted as sulphur-oxidizing bacteria3, unicellular protists4, mesomycetozoean-like holozoans5, green algae akin to Volvox6, 7, and blastula embryos of early metazoans1, 2, 8, 9, 10 or bilaterian animals11, 12. However, their complete life cycle is unknown and it is uncertain whether they had a cellularly differentiated ontogenetic stage, making it difficult to test their various phylogenetic interpretations. Here we describe new spheroidal fossils from black phosphorites of the Doushantuo Formation that have been overlooked in previous studies. These fossils represent later developmental stages of previously published blastula-like fossils, and they show evidence for cell differentiation, germ–soma separation, and programmed cell death. Their complex multicellularity is inconsistent with a phylogenetic affinity with bacteria, unicellular protists, or mesomycetozoean-like holozoans. Available evidence also indicates that the Doushantuo fossils are unlikely crown-group animals or volvocine green algae. We conclude that an affinity with cellularly differentiated multicellular eukaryotes, including stem-group animals or algae, is likely but more data are needed to constrain further the exact phylogenetic affinity of the Doushantuo fossils. (paywall)
And what about “snowball earth” which allegedly ended around 600 mya?
I’m not sure what all the hoopla is about. We have stomatolites, which are assemblages of cyanobacterial species in “microbial mats” held together by polysaccharide sheaths, from at least 2.8 if not 3.4 billion years ago. Oh I know no one pays the slightest attention to multi-cellular prokaryotes, but that is what they are. And I don’t know how you can tell from a phosphorite that it is or isn’t a prokaryotic multicellular assemblage.
Robert Sheldon at 1, I wondered the same thing myself. It feels like celebrating the tricycle in the age of airplanes. But never mind, maybe the next find will be at 700 mya.
I don’t think that this a surprise to many people. For many reasons, the fossil record from that long ago is spotty at best. Very few people think that the animals that appear in the Cambrian just arose fully formed.
To back up Dr. Sheldon’s claim,,,
,,,there is this piece of evidence,,
Of related note, microbial mat ecology is complex and ‘interdependent’.
Indeed the ‘social networks’ of bacteria are very sophisticated and certainly defy any coherent explanation from the simplistic reductive (i.e. bottom up) materialistic narrative of neo-Darwinism:
And as impressive as this ‘social networking’ is of bacteria, ‘that is beyond what we, human beings, can solve with our most powerful computers’, and as damaging as that fact is to the ‘bottom up’ materialistic paradigm of neo-Darwinism, we still do not have evidence to ‘bridge the gap’ between simple aggregates and multicellular life:
In other words, there simply isn’t any evidence in the fossil record indicating that single cells ever formed anything other than ‘simple aggregates’:
Moreover there another whole level of information on a cell’s surface, that certainly must be dealt with in constructing a multicellular creature, that is not reducible to a DNA information theoretic basis as is presupposed in neo-Darwinism:
Dr. Wells does a much better job of elucidating the problem for neo-Darwinism, than I can, here:
Nor does the experimental evidence suggest that such a transition from single cell aggregates to multicellular organisms is possible by ‘bottom up’ neo-Darwinian processes. To highlight the monumental problem that Darwinian processes face in going from a single cell to a multicellular creature, it is important to note the difficulty in obtaining just two protein-protein binding sites,,
And yet, Dr. Behe, on the important Table 7.1 on page 143 of Edge Of Evolution, finds that a typical ‘simple’ cell might have some 10,000 protein-binding sites. Whereas a conservative estimate for protein-protein binding sites in a multicellular creature is,,,
,,,So taking into account that they only covered 2%, of the full protein-protein “interactome”, then that gives us a number, for different protein-protein interactions, of 310,000. Thus, from my very rough ‘back of the envelope’ calculations, we find that this is at least 30 times higher than Dr. Behe’s estimate of 10,000 different protein-protein binding sites for a typical single cell (Page 143; Edge of Evolution; Behe). Therefore, at least at first glance from my rough calculations, it certainly appears to be a vastly impossible step that ‘botton up’ evolution cannot make, by purely unguided processes, to go from a single cell to a multi-cellular creature.
Then there is the ‘ontogenetic depth’ problem in embryogenesis that must be dealt with in constructing a multicellular creature:
Though it is easy to loose sight of the following fact in all the technical discussions, it is important to highlight that embryological development is an amazing, nay, it is a MIRACULOUS process:
Verse and Music:
So we see the first traces of multicellular organisms about 60 million years before the cambrian explosion?
Sounds about right. It’s pretty cool stuff, but what’s the big deal?
as to:
that finding reminds me of this finding
and this,,,