What is considered ‘alive’ anyway?
First of all, no this is not a philosophical question about whether you are even alive if you watch that cringy TV show. This is a question about what separates living entities from non-living but biological entities, and where do the sciency guys draw the line.
Our hearts are decidedly more complex than bacteria cell and yet in conventional wisdom, our heart is not considered alive but those puny bacteria are. So complexity is definitely not a pre-requisite.
How about input, processing and output of materials? That is indeed one of the phenomena. Eukaryotic cells conventionally intake oxygen, process it with other inputs and output waste. This process takes the delicate balance of various entities and cranks them to the max. This process is called metabolism, another essential for life.
So far, in our quest to differentiate between the bacteria and the heart, there isn’t much difference, is there. What is the difference between the two then?
Reproduction is another facet in the equation allowing species to make more of them and create new species through the process of evolution and speciation. This makes so that a species can continue and ‘improve’ over time with new additions for newer conditions.
Regulation of ones own bodily conditions is also a necessity with maintaining pH, salt accumulation and other by-products. A healthy body should have a means of rejecting these said waste materials and making the most out of the waste.
What is the verdict then? Is our heart, or for a matter of fact, any other organ, a living thing, conventionally speaking. The answer is no. For starters, organs cannot reproduce on their own and need the whole body to make a replica. Then there is the problem of our organs not being able to collect their own nutrients. In humans, this function requires special parts like lungs (oxygen), mouth and stomach (food) and the same for water. Our organs say our brain, can't collect these things on their own. You need the whole machinery to work all these things out.
So, does this make our earth a living creature by these rules. The earth collects its own energy (thanks to the sun), processes it (if you consider all the lifeforms on earth as organs) and dispels it in different ways. This is a topic of discussion and maybe more suitable for a philosophy discussion than a science one. This begs the question then, where should we draw the lines for these questions, if any and can the scientific discourse really answer questions like these. And where do things like viruses, which aren’t alive or dead slot in?
Too much to ponder and too much to understand.
Only time will time.
