Posted on 12/03/2003 4:53:26 PM PST by Pharmboy
LONDON (Reuters) - Fossils discovered in Ethiopia's highlands are a missing piece in the puzzle of how African mammals evolved, a team of international scientists said on Wednesday.
Little is known about what happened to mammals between 24 million to 32 million years ago, when Africa and Arabia were still joined together in a single continent.
But the remains of ancestors of modern-day elephants and other animals, unearthed by the team of U.S. and Ethiopian scientists 27 million years on, provide some answers.
"We show that some of these very primitive forms continue to live through the missing years, and then during that period as well, some new forms evolved -- these would be the ancestors of modern elephants," said Dr John Kappelman, who headed the team.
The find included several types of proboscideans, distant relatives of elephants, and fossils from the arsinoithere, a rhinoceros-like creature that had two huge bony horns on its snout and was about 7 feet high at the shoulder.
"It continues to amaze me that we don't have more from this interval of time. We are talking about an enormous continent," said Kappelman, who is based at the University of Texas at Austin.
Scientists had thought arsinoithere had disappeared much earlier but the discovery showed it managed to survive through the missing years. The fossils from the new species found in Ethiopia are the largest, and at 27 million years old, the youngest discovered so far.
"If this animal was still alive today it would be the central attraction at the zoo," Tab Rasmussen, a paleontologist at Washington University in St Louis, Missouri who worked on the project, said in a statement.
Many of the major fossil finds in Ethiopia are from the Rift Valley. But Kappelman and colleagues in the United States and at Ethiopia's National Science Foundation (news - web sites) and Addis Ababa University concentrated on a different area in the northwestern part of the country.
Using high-resolution satellite images to scour a remote area where others had not looked before, his team found the remains in sedimentary rocks about 6,600 feet above sea level.
The quality of being alive is often in the eyes of the beholder, just as the qualities of images are created by the viewer.
I spent many a wasted hour arguing with some of our departed FReepers about the "moment of death", and about whether metabolism was a necessary component of being alive. Anyone who seriously believes in evolution would expect a continuous shading of entities from nonliving to living, with a great deal of ambiguity at the lower limit of complexity. And that is exactly what we find with prions, viruses, mitochondria.
Only believers in vitalism would have a need for a sharply delineated definition of life.
And thank you for bringing Ervin Bauer to the table!!! I was hoping someone would because of some things Ive been reading lately.
And thank you for introducing me to the Pannenberg's definition of life. I decided not to wait for Christmas, so my copy of his book is in transit (LOL!)
It was my hope that this thread could explore the current thinking among the scientists, mathematicians and philosophers who post here so we could all have a wider view of opinions as to where the line ought to be. Or as Pearson asked:
For instance, Pannenbergs definition includes a resistance to entropy. However, entropy in information theory (Shannon entropy) is roughly a failure to communicate. For robots, meeting a bar of self-transcendence by successful communication is not particularly difficult. Neither is ecstasy difficult for information process if one considers the methodology of RWPs computer virus.
If an object of a candidate definition is to exclude artificial life, then perhaps the question will indeed turn to quantum field theory:
Your thoughts? ..
Agreed.
A computer virus most definitely, in reproducing itself, decreases its entropy (of course, so do many growing crystals, ice on a freezing lake, etc). It's a code in the same sense the viral DNA or RNA is a code; it's simply written in a different language on a different medium. And it is written by a human rather than evolving from a piece of parasitic nucleic acid; however, I believe people have tried to develop computer viruses that can mutate their own code and evolve. It is hard to find a meaningful criterion, relevant to the dicussion of what life is, by which a computer virus differs from a biological virus.
BB, by that defintion, computer viruses are most certainly alive, as are many cellular automata, and chain letters.
He writes, An organism lives in its environment. It not only needs and actively occupies a territory but it turns it into a means for its self-realization, it nourishes itself on its environment. In this sense, every organism lives beyond itself. Again it becomes evident that life is essentially ecstatic: it takes place in the environment of the organism much more than in itself .
A chain letter lives in the environment of human correspondence; it propagates itself by means to a weakness in the human psyche, as most parasites live by expoliting weakness in their host's defense; it is marginally lower in entropy tham a blank sheek of paper and a bottle of ink (or paper and a toner cartridge).
I'm arguing by reduction ad absurdam here. I believe life is simply a category, and like most categories it has fuzzy edges. But most attempts to make precise demarcations of life either include things like chain letters, which don't really seem to belong in the same category as amoebas and koalas, or make unscientific vitalist assumptions, which Pannenberg apparently does with his 'energy field', or include what seem to be arbitrary requirements, for example that life must contain DNA or RNA.
At least with viruses we can limit the discussion to observable behavior. For a fun time, start talking about the minimum neural complexity necessary for consciousness.
OTOH, is it valid to exclude Artificial Intelligence but accept artificially created biological life forms? Or should the term always be qualified, i.e. natural life v artificial life?
I don't know of any viruses like that "in the wild", but it would certainly be an interesting challenge to try putting one together. The closest thing I can think of to "mutation" are polymorphic viruses, which aren't really "mutating" in a stringent sense anyway - they are designed to change their appearance but preserve their functionality, in order to defeat signature scanners. But there is, by design, no chance that they will randomly develop new functions or abilities - the underlying functionality is always preserved - and hence no chance of "evolution".
I wonder about the possibility of "evolving" a solution, though. Writing a virus is trivially easy - writing a virus that can slip past a sophisticated "immune system", which is what modern antivirus packages are, really - is a much taller order, one that might be crackable by allowing genetic algorithms to go to work...
You: It would be more concise to assert that nobody has a solid idea as to the mechanisms behind QM, but that the consequences of QM from the standpoint of things like mind and computational theory are obvious.
It may be more concise but I would not agree that the consequences of QM from the standpoint of mind have at all been explored or are at all understood. I think they are definitively not understood. And certainly not obvious. As to computational theory, I don't know, although I don't think a turing machine will "get us there" (due to Godel's Incompleteness Theorem, a la Penrose).
I believe I recall that you are among the most able and strongest proponents of Strong AI, so I'm sure you will correct me if I have gotten my computional theory comments wrong.
Moreover, strong determinism - including the absence of free will - and strong A.I. which can substitute for humanity in every respect - are the logical consequences of Pinker's "the mind is what the brain does".
Please note Elsie, it wasn't me that claimed it. Plus I also have the audacity to hold, unlike some evos, that there is such a thing as an Alpha male, for which it gets implied here that I must then be a rapist LOL
I think any definition of life, no matter how carefully considered, will contain some arbitrary elements. I'm willing to consider an artificially intelligent entity alive, even if it can't self-replicate, provided its behavior is sufficiently interesting. I've never met a human who could self-replicate, but if one existed in complete isolation I would consider him/her to be alive.
But don't bother. The grown ups are having an intelligent discussion here. Why don't you go throw rocks somewhere else?
I'm reading an excellent book that appears to be trying for just such a synthesis (i.e., between quantum mechanics and classical physics): Lynne McTaggert's The Field (2003).
She has already been criticized around here as incompetent to undertake such a work, because she's "only a journalist." (This from persons who haven't read her book no less, and who have stated it is unnecessary to do so -- because she's "only a journalist.").
But when you look at the extensive list of world-class authorities, working in a variety of fields, from some of the most prestigious science establishments on the face of the earth who she interviewed and consulted for this work -- and who reviewed it and commented on it before publication -- I think to dismiss her like this is unwarranted and entirely premature.
Phaedrus, a venture like this -- a reconciliation of QM and Newtonian physics -- would appear to be necessary. For as Wolfhart Pannenberg points out, quantum mechanics "does not abstract from time" -- that is to say, the category time per se is not relevant for it. But it certainly is relevant for our understanding of life and the Universe.
Which brings me to the allegation that a computer virus can be considered "alive" on the Pannenberg/Bauer criteria of life. The computer virus must somehow be aware of a future in order to qualify as a life form. This would have to be programmed into it, assuming this were possible to do; where for human beings, the time sense is completely "natural." The program would have to specify the virus' "concept" of future not just once; but to relate each and every adaptation it ever makes in terms of a future that any adaptation will change. IOW, a life form works toward a future goal that already exists for it in anticipation. Thus, the future must be more than a simple toting up of a series of "presents" extrapolated forward. Under the criteria we are discussing, to be "alive," the "goal" of its life must be "self-preservation" -- and the preservation of its future "offspring," the future generation of the particular computer virus....
If it can do that, then maybe then we can talk about whether it's alive or not.
To repeat what Panneberg wrote, "But there is still another aspect of [a living organism's] living beyond itself: by turning its environment into the place and means of its life, the organism relates itself at the same time to its own future and, more precisely, to a future of its own transformation. This is true of every act of self-creation and nourishing and developing itself, by regenerating and reproducing its life. By its drives an animal is related to, although not necessarily aware of, its individual future and to the future of its species.
A-G, you wrote: "Moreover, strong determinism - including the absence of free will - and strong A.I. which can substitute for humanity in every respect - are the logical consequences of Pinker's 'the mind is what the brain does'. "
Only human beings among earthly life forms appear to be aware of a future, and to consciously relate to it. Are brains aware of the future? If so, by means of what mechanism?
Animal behavior, Pannenberg notes, is pointed torward the future of the organism, but in a manner that is not necessarily self-aware. Human consciousness is self-aware; and human life is consciously directed toward a future, supported by the free actions (free will) of human beings. Animals have to settle for basic drives, instincts -- the information set specifying the individual organism -- which basically direct them toward their future in time and that of their species without the necessity of self-aware consciousness.
This is the absolutely critical difference between humans and the higher animals. A computer virus would appear as not qualifying as a living organism -- unless somehow the virus could become either sensitively aware (i.e., self-aware) of "future," or effectively "controlled" by it, such that it could preserve itself and its species.
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