5 short stories on the
Origin of Life
What is life, anyways? We can label the items around us as
living or dead fairly easily: Me? Alive. Chair? No. Plant that I haven’t
watered in a month? Might still be kickin’ -- gotta love succulents. Computer?
I wish. Than I could be chatting up Scarlett Johansson like that guy in Her. Below are five short (but true!) stories on the origins of life here on our cozy little planet earth.
 |
| The Honey Mushroom stretches for miles underground |
But really the division for life and non-life is hard to
pinpoint because it lies at the cellular/acellular divide. From big Blue
whales, Giant Sequoia trees, and the truly massive Honey mushroom in Oregon down to the smallest Paramecium, or the truly tiny Mycoplasma genitalium (one of the smallest bacteria) all of these diverse
organisms get labeled as living because they are all forms of self-replicating, ribosome-utilizing cellular life.
Viruses, Protein, DNA all fall short of this definition of
life. The largest known virus, the Pandoravirus, at 500 nm wide and 1000 nm long is bigger than the tiny
archaeon Nanoarchaeum equitans (300 x 300 nm) and even though both depend on
host cells for survival, the poor Pandoravirus doesn’t get the label of being
alive. M. genitalium at least has the
potential to grow and divide outside of a host cell as it has the ribosomes
necessary to translate RNA to protein.
 |
| Nanoarchaeum equitans, the smallest cellular life |
The next story on Magma oceans and marauding asteroids soon to come... but this is my first attempt at a blog, so excuse my ignorance as I try to figure it all out.
