I am a geologist and paleobiologist who works on very old limestone. Recently, I described this exact microstructure in 890-million-year-old rocks from northern Canada, proposing that it could be evidence of sponges that are several hundred million years older than the next-youngest uncontested sponge fossil.
This may be an 890 million year old sponge fossil. (Elizabeth C. Turner), Author provided
Although my proposal may initially seem outrageous, it is consistent with predictions and assumptions that are common in the paleontological community: the new material seems to validate an extrapolated timeline and a predicted identity for early animals that are already widely accepted.
If these are indeed sponge fossils, animal evolution can be pushed back by several hundred million years.
The early possible sponges that I describe lived with localised cyanobacterial communities that produced oxygen oases in an otherwise low-oxygen world, prior to the Neoproterozoic oxygenation event. These early sponges may have continued living in similar environments, possibly unchanged and unchallenged by evolutionary pressure, for up to several hundred million years, before more diverse animals emerged.
The existence of 890-million-year-old animals would also indicate that biological evolution was not substantially affected by the controversial Cryogenian glacial episodes — so-called “snowball Earth” — that began around 720 million years ago.
My unusual fossil material may provide a new perspective on Darwin’s dilemma. However, radical new ideas are generally not fully accepted by the scientific community without vigorous discussion; I expect lively controversy to ensue. At some point, probably years in the future, a consensus may develop based on further work. Until then, enjoy the debate!
This marvelous story was headlined, over at the CNN website, with a picture of late-Cretaceous dinosaurs. I had to point out to people that those dinosaurs lived between 800 and 900 million years after those sponges, and that that’s when we live, too.
I love science it always knows what it knows so adamantly until it doesn’t know what it knows anymore.
In this case, one of the mysteries we’ve been facing is that molecular estimates of divergence times suggest an earlier date for the origin of some groups than the fossil record supported. Showing genuine metazoa 890 million years ago suggests that the molecular estimates might be right after all.
But, you know, if it seems to you like a bad thing to change your mind about something when new evidence challenges what you previously thought, then yes, science is definitely a bad thing. Some of us like it, though. Takes all kinds, I guess.
Not at all I’m actually quite progressive and open minded and pragmatic and that’s my complaint that a lot of science seems to be more dogmatically chained to believing what it postulates to be the truth on Monday until new evidence is presented on Tuesday that they finally accept on Wednesday so to speak
For science the Earth was flat until it was round. And it was the center of the universe, until the sun was the center of the universe. Until we figured out no, that’s just the center of our Solar System and there’s other galaxies.
also we we thought to be something like 99% close to chimpanzees until we figure out know we’re actually a little farther apart maybe 98% or even 97% and in biological terms even decimal points can make a planet of the apes difference.
I think you’re attributing a lot of pre-scientific views to science, as well as a dogmatism which is quite absent. As for percentages and chimps, there are various ways to characterize that, and so there are various numbers. But the similarities, morphological and genetic, are indeed quite extreme, and they do point to the conclusion of our common ancestry.
As for the Planet of the Apes, well, I’m not sure that’s necessarily a scientific portrayal. Though Roddy McDowall was quite good, and the orang(e) leader Dr. Zaius was a weird glimpse of a simian future few of us thought we would live to see.
Could you please tell us when the Earth was flat according to science?
It might help us pitch our responses to the correct level of expertise.
All of these weren’t scientific ideas. They were held long before science came in to investigate.
At the level of single nucleotides, we are ~98.8% similar to chimps. Our protein coding genes are 99% similar to that of chimpanzees.
Percentage is lower than 98.8% when you look at chromosonal inversions and translocations.
The divergence of human and chimpanzee ancestors dates back to approximately 6,5–7,5 million years ago  or even earlier . It is still of a great interest to identify genetic elements that distinguish humans from chimpanzees and encode features of human physiological and mental identities [3,4,5]. It’s a difficult task to quantitate the exact percentage of differences between human and chimpanzee genomes. In early works, divergence of human and chimpanzee genomes was estimated as roughly 1% . This estimate was based on the comparison of protein-coding sequences and didn’t consider non-coding (major) part of DNA. However, the idea of ~ 99% similarity of genomes persisted for a long time, until 2005 when nearly complete initial sequencing results of both human  and chimpanzee ( Pan troglodytes )  genomes became available. It was found that genome differences represented by single nucleotide alterations formed 1.23% of human DNA, whereas larger deletions and insertions constituted ~ 3% of our genome . Moreover, even higher proportion was shaped by chromosomal inversions and translocations comprising several megabase-long chromosomal regions or even entire chromosomes, as for the chromosomal fusion that took place when the human chromosome 2 was formed .
Also this applies to humans as well. On average, any two humans are ~99.9% similar at the level of single nucleotides. Throw in indels and other structural changes and that drops the similarity score.
I clearly stated I was referring to differences at the “level of single nucleotides”. You really do have a comprehension problem.
As I said, you can get different numbers by different methods. But why does this matter to you? Surely the number, isolated from any real understanding of the genome and its function, is pretty much meaningless. It seems to really agitate some people, though, and they want it to be lower rather than higher. Why? Nobody doubts that we share recent common ancestry with chimpanzees; the number is just a shorthand way of expressing one aspect of that, and changing the number doesn’t change the facts.
Why did you terminate the quote right where the paper began discussing the origin of those elements? That seems like an odd thing to do: ask where they came from, while omitting the statement of where they came from.
I don’t know that much about specific mutational processes, and am not the best reference to turn to if you want to understand such things. But the fact that there are various differences between humans and chimps (e.g., chimps don’t ask questions they could easily have answered by reading the paper in question) doesn’t in any way change our common ancestry with chimpanzees, which is both genetically and morphologically beyond any plausible denial.
Seems like a quote mine. Please do not do this, it only wastes everyone’s time.
That would be 98.77% not 98.8%
No one said you didn’t say that, I’m contributing additional information that also needs to be taken into consideration within the rational analysis.
I believe the figure is 99.5% (exons only).
You can’t turn those into percentages, so it’s unclear what you’re saying. Unless you interpret the length of an inversion as that number of mismatches in nucleotides, which seems silly.
That’s gold, Jerry! Touche!
Sometimes he doesn’t understand what he reads.
I read that paper last year and we have discussed it several times in older threads on PS. You aren’t telling us anything new, sorry.