I always wondered why life needs to reproduce at all costs. Even viruses reproduce by invading cells. I think I've stated this before, but fire is almost life isn't it? It grows, eats, breaths, reproduces.
Here is a definition of life I think is kind of arrogant and I diasgree with:
Life Is Cells
People like to say, as if it were obvious, that life is hard to define. This is simply not so. Life has properties that clearly distinguish it from everything else. Every living thing is cellular. In other words, it is either a single-celled creature or a creature composed of biological cells. Every cell is bounded by its own outer membrane and contains a full set of instructions necessary for its operation and reproduction. Furthermore, every cell uses the same operating system: "DNA makes RNA makes protein." DNA is a long complex molecule that contains the cell's instructions. It is transcribed into RNA, another long complex molecule similar to DNA; and then the RNA transcript is translated into protein. There are hundreds of billions of different proteins used by living things (3), but all of them are made from the same twenty amino acids, the "building blocks of life."
It seems to me that all OBSERVABLE life is cellular, and it seems that even cells are composed of smaller 'life' This same definition discounts viruses as life, but I disagree.
Viruses and prions are not alive. Viruses and prions lie on the fringe of life. Viruses contain instructions encoded in DNA or RNA. (Prions don't.) Both are reproduced. Viruses certainly and prions probably can evolve. But neither can reproduce itself; a virus or prion needs the machinery of a living cell to carry out its reproduction. Without a cell, each is merely an inert, complicated particle which does nothing. Do viruses and prions make it hard to define life? No, just as trailers don't make it hard to define motor vehicle traffic. We know what motor vehicle traffic is. And we know what life is.
Remember that metorite found in antartica with possible fossils of bacteria? The work was dismissed because the fossils would indicate bacteria much too small to be life 'as we know it' Remember that song star trekkin'? In it Mr. Spock from star trek says 'It's life jim, but not as we know it, not as we know it, not as we know it Jim'
The problem I guess is that therese seems to be no universally accepted definition of what exactly'life' is. The deeper problem is that life on Earth -- in Spock's words, "Life As We Know It" is the only life we know -- we can't say diddley nothing about what life might be like elsewhere in the Universe. We can't assume that extrateresrtial life is constructed along the same lines as earthly life.
For example, we can't assume that aliens carry their genetic information around as DNA, or perform the kinds of metabolic processes we see in, say, bacteria or peguins.
I disagree with the above definition of life cuz we must avoid pinning life to terrestrial peculiarities, such as the presence of DNA as a genetic material, or even terrestrial life's foundation on the chemistry of carbon in liquid water. I posted earlier about how life can also be silicon-based or nitrogen based. We're carbon based cuz the temperature on earth dosen't boil liquid away. That we are based on carbon explains our need of water and liquids to live.
so like, maybe life redproducing at all costs is how life on earth behaves and not elsewhere? Is reproduction a nessecity of life? In a broader scale, is death nessecary for life? Do living things need to die in order to weed out the weak and leave only the fittest, thereby ensuring long-term survival? If life didn't really ever die, would it be impossible for it to evolve and thereby become something better?
If death is a constant necesity of life, then is a reproduction a by-product of that reality, since the organism dies, it needs to replenish itself? Is our life and death simply a grander scale of what goes on daily in our bodies as cells reproduce and die?
I've heard that a language can almost be considered alive, or even computer code. Maye we won't get a good idea of what exactly life is until we meet extraterrestials and have something to compare our observed life to.
-Dan the carbon-based bipedal binnocular-visioned ominviorous sentient corporeal lifeform.