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Madeleine KandoAnother year has ended and we are all excited about it. We made new year’s resolutions which we probably won’t keep and we convince ourselves that the new year will be better than the last. But the real reason for all this frenzy is to celebrate the fact that the Grim Reaper hasn’t come knocking at our door.
But what’s so special about a year? Why not a day? A month? A century? Doesn’t that reek of anthropocentrism? There is no line drawn across the universe that says: “Today is January 1 2023.”
Some insect species never live long enough to celebrate New Year. They don’t even make it to the next day. The female mayfly ‘Dolonia Americana’ only lives for a few minutes as an adult. Can you imagine having to do your entire life’s business in under 5 minutes? Learn to fly, find a mate, make babies and then lay eggs in a safe spot? You wouldn’t have time to eat or go to the bathroom (which is just as well, since mayflies don’t have a mouth). You wouldn’t have time to retire and write your memoirs. You couldn’t wish anyone Happy New Year! You could wish your buddies Happy New Minute, but even that would not fit in your busy schedule.
Ordinary house flies are given some wriggle room, but they too have to cramp their entire lives into a few weeks. No wonder they are so determined to land on that sugar cube, no matter how many times you try to squash them. *
Mammals are somewhat better off, but some still have to sprint through their lives before their time is up. The lowly mouse lives only 18 months and a shrew lives for only about a year. Their metabolic rate is too high to allow them to live much longer. On the other hand, bowhead whales, the longest living mammal on earth, can live over 200 years.
Amazingly, some animals grow extremely old, because they have what is called ‘negligible senescence’. Senescence is the condition or process of deterioration with age, which means that once an animal grows old enough, it stop growing old. An example of negligible senescence is the Greenland shark. Covered with battle scars, it can live up to 500 years. Similarly, the 500 year old Ming clam could have gone on living its incredibly long life, were it not for a bunch of marine biologists who fished him out of the ocean and froze him on board to take him to the lab. Of course he instantly died.
In the plant kingdom life spans begin to increase dramatically. The Pando tree, one of the oldest organisms on Earth, is 14,000 years old. It is really a colony of clones of an original tree, but all of the trees are connected through an underground network of roots. In this way, aspens continue to live long after a single tree may fall or die.
There is another organism that deserves our respect for having lived so long. It is a type of mushroom called the ‘Humongous Fungus’. It occupies some 2,000 acres of soil in Oregon's Blue Mountains and is the world's largest known organism. Based on its current growth rate, it is estimated to be 2,400 years old but could be as ancient as 8,650 years.
Scientists found a patch of sea grass off the coast of Spain, the Posidonia oceanica, which is about 200,000 years old. This makes it the oldest living thing on Earth. It was already alive when the first modern humans roamed the African Savannahs.
Another strategy to extend one’s life span is ‘dormancy’. On a daily, more modest scale, gardeners witness this process when they buy seeds at the local garden store. Aren’t those seeds of plants sleeping in their little paper bags until they germinate? But some organisms manage to stay dormant for a few millennia. Scientists revived tiny Siberian Nematode worms that had been frozen in permafrost for 42,000 years. Once unfrozen, they started moving and eating.
Another clever way to increase your life span is to do what the Turritopsis dohrnii does. When injured or starving, this pea-size jellyfish reverts back to a previous stage of its development, in a rare process called ‘trans differentiation’. The born-again polyp colony releases medusae that are genetically identical to the injured adult. It is a bit like a butterfly turning back into a caterpillar, or a frog becoming a tadpole again.
There is something refreshing to realize that a year is not all that significant for most other species on earth. A minute for the mayfly, a century for the Greenland shark, a millennium for the Pando tree. It is all relative. Still, today, the first day of a brand new year, reminds me how lucky I am to be alive. That is why I wish you all a HAPPY NEW YEAR!
* There are exceptions to the rule, of course. A queen termite can live up to 50 years, long enough to produce an army of hundreds of thousands of termites that can devour an entire house.
6 comments:
‘negligible senescence’. It also applies to the human species, to wit, some members of Congress.
Brilliant.Thanks Madeleine. And have a very happy One! ❣
Your year end "negligible senescence' piece puts some perspective on things. My 50 foot pine tree went down on New Years night in torrential rain and wind. It could have taken my house and me with it. I have only gratitude that I am here to mourn the loss of an old friend.
Daniel: You are so right: Senescent cells (read: members of Congress) don’t die off when they should. They instead remain and continue to release poisons that can propagate. Like the one moldy piece of fruit that corrupts the entire bowl, a relatively small number of senescent cells (MOC's) can persist and spread poison that can damage neighboring cells (MOC's).
Unknown: your pine tree truly gave you a reason to celebrate the New Year. It went down majestically, without causing any undue harm. I hope it was a white pine. They are the noblest of pines.
Happy New Year to you, Csaba. boldog új évet? Not sure, on the way to negligible senescence, I forgot my Hungarian.
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