A finger bone found in a cave in 2006 in Russia has scientists re-examining their assumptions about early human history. A DNA analysis would suggest that proto-humans left Africa about a million years ago and traveled as far as Siberia. Of course, now that Sarah Palin is a host on Discovery Channel, she may have her own views given that she believes scientists have forgotten that the Earth is only a few thousand years old.
It is unclear what this group looked like, but they may have existed as recently as 40,000 years.
Terry Brown, a molecular paleontologist at the University of Manchester, put it simply: “People are going to be what we call ‘gobsmacked’ by this news. There is going to be open-mouth amazement.” For those without advanced molecular degrees, that means that people will be utterly speechless.
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herra tick said:
Interesting comment – I find myself most intrigued by the question of ‘artificial life’ either in the sense of the article that Gyges linked to or in the sense of a von Neumann machine.
— Slartibartfast
thanks for your thoughtful answer.
i agree that the wikipedia definition is very unsatisfying, as well as unclear. i have a few issues with wikipedia that we can cover another time. it hss apparently been an area of discussion, and i would rather it not be part of this thread.
i mostly agree with your list. as with all these kinds of things … the proof is in the semantics. =]
1 — “growth through metabolism”
if you use the model “intake – modify – expel”, you can force the definition of metabolism to include “interaction with environment”. it should include this. i think environmental interaction, and the boundaries it would have to form, are part of the groundwork necessary to call something life. life needs to be seperate in some way, at some level.
here’s a pieced together definition for metabolism i like:
— system to covert external material, to yield energy for vital internal processes —
2 — “reproduction”
i agree, life does need a system for progeny. i am in no way a hard scientist, but i can visualize any number of systems, from clonig to self-replication and improvement by computer intelligence.
3 — “adaptation to it’s environment through changes originating internally”
this could almost be exceptable, stand alone. it includes an internal drive, as a response to external stimulus, which should lead to the boundaries i think are important. you would need to allow for the absence of progeny, which i think leads to unnecessary, unworkable problems. i would want to make sure progeny stays in the definition, somehow.
i do see the scientist in your answer
(not a bad thing, in and of itself) =]
i think mine would include…
“boundaries”
i think life needs to have localization, which is impossible if there is no boundary between itself and everything else. boundary disolution, of just about any kind, can be very threatening to an organism.
“awareness”
awareness is the root of “interaction with environment”. an organism needs to have some form or forms of feedback (perception / awareness) in order to fulfill it’s needs: food, procreation, protection … “warmth detection units” so you know the best angle to point your leaves to maximize sunlight =]
“change”
this one seems a little trickier in my mind. it seems that an organism is doomed if it does not change and/or improve. call it keeping up with the johes’s, or maybe the predators. i am not sure this is necessary to be “life”, but i think it is necessary to remain “life”.
“progeny”
i would include the need for some kind of progeny. as i said earlier, i think there are lots of viable methods for this.
here’s an example – huge stone v foot.
the stone has a structure, and if that structure fails, there is no system for the stone to restore itself, nor does it try, or care.
the foot, more likely crushed, needs to have several toes amputated. the foot will go to great lengths, and adapts as best it can, in an attempt to maintain it’s original form and function.
herra tick,
Wikipedia says:
I don’t find this very satisfying and I’m too lazy to find the definition used in an episode of Star Trek (TNG) so I guess I’ll have to wing it… I would say that rather than give a definition it is better to list the requirements for life. Dictionary.com says:
So I would say that life has the properties:
1. Growth through metabolism
2. Reproduction
3. Adaptation to its environment though changes originating internally
I can’t think of anything that satisfies these properties that I wouldn’t call life (or anything that I would call life that doesn’t). Of the three, I could imagine that there could be life as we don’t know it that doesn’t satisfy #2. Since we know how to immortalize cell lines using telomerase, immortal cellular life seems possible but evolution (at least as we know it) requires reproduction (and mortality).
Aside to Duh:
I was having a meeting with my thesis advisor (the chair of the Duke Math department) this week and we were investigating how to obtain the characteristic equation of a system of coupled hyperbolic partial differential equations and the first thing he did was to try Wikipedia, which made me laugh. He agrees with me that Wikipedia is a good place to start when doing research. 😉
— Slartibartfast
if “bio” means life, i’m assuming you can’t be using it to differentiate human “life” from some sort of computer, or other, “life”. biology would have to mean the study of any form of “life”. so we need a definition of life. got a favorite?