Posted on 01/29/2002 3:48:35 PM PST by aculeus
An extraordinary group of jellyfish fossils has been uncovered by researchers in a quarry in Wisconsin, US.
The circular impressions left in 500-million-year-old sandstone - several measure up to a metre across - represent some of the largest finds of their kind anywhere in the world.
It is very unusual for jellyfish to be preserved in the fossil record; they have no bony parts and when they are stranded on a beach, they are usually eaten by predators.
These jellyfish must have been covered by sand soon after they came ashore.
"It is very rare to discover a deposit which contains an entire stranding event of jellyfish," said Dr James Hagadorn, a scientist at the California Institute of Technology and co-author of an article reporting the find in February's issue of the journal Geology.
"These jellyfish are not just large for the Cambrian, but are the largest jellyfish in the entire fossil record. What is also of interest is that they were among the largest two types of predators in the Cambrian."
During the Cambrian, Wisconsin is thought to have enjoyed a tropical environment, and was most likely covered by a shallow inland sea.
Skewed view
Dr Hagadorn and colleagues believe that the jellyfish were preserved because of a lack of erosion from seawater and wind, the lack of scavengers, and the lack of any significant sediment disturbance by other organisms burrowing into the sand after it had covered the jellyfish.
Hagadorn believes jellyfish may have been under-appreciated in previous studies of Cambrian ecosystems and that they were probably important predators in Cambrian food chains.
"We use fossils to assess the diversity and ecology of ancient communities," the geologist said. "To date, most of our information about the trophic (food chain) structure of the Cambrian - when multicellular animals burst onto the scene - is based on animals with hard parts or on exceptional deposits which contain soft-bodied organisms."
He added: "When we analyse the trophic structure of the Cambrian - who ate whom, who ate them, and so forth, or when we analyse how abundant each type of organism was in each part of the food chain - we may have been inadvertently omitting a huge amount of information about all of the soft-bodied animals that were swimming around in the water column, munching on other organisms, but which were rarely fossilized.
"This deposit provides us a rare opportunity to study such animals."
'Swimming' implies directed movement, something modern jelly fish are incapable of.
'Munching' suggests chewing, of which no jelly fish is capable.
Question unaddressed in this article (and in Biology literature) why didn't they evolve in 500 million years? Unpunctuated equilibrium (as if that would explain anything)? Or something else?
There was a mass extinction about 250 million years ago that wiped out not just entire species, but entire FAMILIES all over the planet. It was much bigger than the dinosaur extinction. Maybe that has something to do with it.
Question unaddressed in this article (and in Biology literature) why didn't they evolve in 500 million years?Because they didn't need to. They survived just fine without changing. Evolution is not about going from simple to complex or from "worse" to "better". It is about surviving in your enviroment long enough to reproduce.
Because they didn't need to. They survived just fine without changing. Evolution is not about going from simple to complex or from "worse" to "better". It is about surviving in your enviroment long enough to reproduce
You're confusing survival with evolution. Evolution means change. 500 million years ago our ancestors were bony fish swimming in the same environment as the jellyfish. Supposedly the jellyfish and the vertebrate fish had access to the same evolutionary mechanisms. Yet some fish became amphibians, reptiles, birds and mammals while the jellyfish remained jellyfish.
There is a mechanistic answer to this ignored question which has been pubished in a peer-reviewed journal and you'll find it here LINK
There are some serious problems with evolutionary theory (I was a minor in anthropology and studied et at length).
Imagine my surprise when I discovered that some evolutionary "scholars" (Stephen J. Gould comes to mind) were perpetrating LIES - such as the spotted moth story.
Curiosity piqued, I started a study and found all kinds of anomalies in et. I'd suggest that others, similarly interested, conduct their own research into how often - and how pathologically - the Left lies.
Better watch out, though. I became a diehard conservative!
Further books of note
Cancer Selection: The New Theory of Evolution by James Graham. Lexington (VA): Aculeus Press, 1992. xiii + 213 pp. $35, cloth. ISBN 0-9630242-0-5.
What brought about the division between plant and animal kingdoms?
James Grahams answer is, Cancer. Graham, who is an amateur and not a professional scientist, published the idea in the early 1980s in the Journal of Theoretical Biology. Disappointed that his insight was not taken up in the scientific mainstream, he published this book in 1992. Unfortunately it has typical shortcomings of self-published works, chiefly that it mixes substantive working through of the idea itself and the evidence for it with argumentation about sciences attitude toward the idea. Nevertheless the book received a supportive review in Nature.
In a nutshell, Graham argues that plants and lower life forms are relatively simple, with nothing like the complexity of animals, which have so varied a set of disparate tissues and organs. For so complex a creature to develop successfully from a single fertilized egg requires a most impeccable control of cell differentiation and multiplication. Cancer, of course, is uncontrolled cell division and multiplication. So for development to be successful, cells must be able to stave off any tendency to become cancerous. Thus the evolution of cancer defenses is what enabled the evolution of complex animals.
The theory demands that all animal cells harbor potentially cancerous tendencies; and in point of fact it seems that all animal cells do indeed possess oncogenes which, when activated, cause cancer. Graham also presents other evidence for his theory and other potential tests of it. The book is well worth reading by anyone who has wondered how normal gradual Darwinian evolution could possibly have brought about a new genus or a new family, let alone a new kingdom like that of the animals. (Another mechanism, by no means mutually exclusive with cancer selection, is symbiosis, proposed and worked out by Lynn Margulis.)
Henry H. Bauer
Professor Emeritus of Chemistry & Science Studies
Dean Emeritus of Arts & Sciences
Virginia Polytechnic Institute & State University
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.