Life?

Originally posted by Kepler
I think we are at cross purposes here. I am not asking about the quality of life, I am asking what makes something alive rather than not alive. A rock is not a living thing, a squirrel is a living thing. What is the difference, what makes one alive and the other not.

ok, I dunno

Originally posted by robbie carrobie
ok, I dunno

You and me both.

Originally posted by Kepler
So bacteria, fish and many humans aren't alive? I don't think I'll be going with that one thanks.

To each his own. You're telling me that fish don't breathe?

Originally posted by RBHILL
To each his own.

Anything that has blood flowing is life

Originally posted by RBHILL
To each his own. You're telling me that fish don't breathe?

They don't breathe air!

Originally posted by RBHILL
Anything that has blood flowing is life

Which cuts out bacteria, trees, jellyfish, and others. But I think that's getting us somewhere.

Originally posted by Kepler
Which cuts out bacteria, trees, jellyfish, and others. But I think that's getting us somewhere.

I don't think trees are really alive, but if you want to say their blood is sap.

Originally posted by RBHILL
I don't think trees are really alive, but if you want to say their blood is sap.

Trees have cells that look remarkably like the cells you find in us. They have DNA, mitochondria, ribosomes, all the equipment of living cells. Blood cuts out jellyfish, flat worms and various other organisms that my biologist friends say are alive.

Why is blood the deciding factor? And does it have to be red?

Originally posted by sonship
Some of us may get tired of atheists putting up OPs and sitting back to wait for the wrangling, while they just resort to pointing out this and that problem. The tactic seems to always leave all the heavy lifting to theists while you atheists just spot errors.

That's because atheists tend to make fewer claims. When you make a claim such as '"life must ...." then you have to define life. If you dislike evolution and claim "no species can evolve into another species" then you must define 'species'. If you claim "information cannot arise without intelligence" then you must define both 'information' and 'intelligence'. When you make far reaching claims about loosely defined terms you are bound to suffer some criticism. Its like when you say "all white people are stupid" the first question might be "what about if one great grandparent was black"?

Originally posted by Kepler
Trees have cells that look remarkably like the cells you find in us. They have DNA, mitochondria, ribosomes, all the equipment of living cells. Blood cuts out jellyfish, flat worms and various other organisms that my biologist friends say are alive.

Why is blood the deciding factor? And does it have to be red?

Because life and death are in the blood.

I stumbled upon this site, but it is way over my puny brain, maybe one of you who are much smarter than myself can decipher this thing....

http://www.edge.org/conversation/what-is-life

Originally posted by Kepler
They don't breathe air!

They do. They take water in through the mouth and they
are able to filter the oxygen from it and then the water gets
flushed out again through the gills.

If you pull a fish or a shark backwards they drown.

Originally posted by robbie carrobie
ok, I dunno

Ha ha finally you're speechless and stumped.

Facts of life ......................................................1
Robbie the religious wizard from Lord of the rings......0

Originally posted by johnnylongwoody
They do. They take water in through the mouth and they
are able to filter the oxygen from it and then the water gets
flushed out again through the gills.

If you pull a fish or a shark backwards they drown.

Oxygen is not air. Put a fish in air it dies because it cannot absorb atmospheric oxygen, it has to be in solution. Fish don't drown if you pull them backwards because they actively pass water over their gills. Sharks supposedly have to move forwards to do the same. There are some sharks that can rest on the bottom without moving for considerable periods of time thus showing that movement is not necessary for shark "breathing".

From Wikipedia:


Since there is no unequivocal definition of life, the current understanding is descriptive. Life is considered a characteristic of organisms that exhibit all or most of the following:[29][31]

- Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.
- Organization: Being structurally composed of one or more cells — the basic units of life.
- Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
- Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
- Adaptation: The ability to change over time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity, diet, and external factors.
- Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion; for example, the leaves of a plant turning toward the sun (phototropism), and chemotaxis.
- Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.

These complex processes, called physiological functions, have underlying physical and chemical bases, as well as signaling and control mechanisms that are essential to maintaining life.

From Biology-Online.org:


Despite of the irresolute answer for questions about life, the basic characteristics of a living thing are as follows:

- with an organized structure performing a specific function
- with an ability to sustain existence, e.g. by nourishment
- with an ability to respond to stimuli or to its environment
- capable of adapting
- with an ability to germinate or reproduce


So if it moves, grows, responds to it's environment and can reproduce, then it is probably alive. However, there are things, for example viruses, that only do some of these things. Whether we call them 'alive' is debatable.