Saturday, August 27, 2016

Demons of the Deep

It is curious how so many life forms that grow in gradual and deliberate increments, live to such lengths. The tortoise with its fabled torpid movement, the century year old sea turtles, or the ancient Sequoia Redwoods. As with all trees that grow slower, they live longer, so there must be something to a slow growth rate. I suppose slow and steady does win the race.

My main question with this article however, is how do they really know the age of these sharks. The article seemed not to be speaking of any particular shark specimen they had found but rather, the species in general, as being the longest living vertebrae. It also seems an odd range of years to put the lifespan of the species at an exact 272 years. The article writes of the age-telling technique of measuring radioactive levels of carbon-14 in the eyes of the sharking (sounding like a complex and therefor accurate science), yet the range of possible age for the largest of the sharks collected in a 2010 study was between 272 and 512. That sounds laughably inaccurate, literally a range of 240 years. If I read this wrong I'd like to know but it seems to me they need to arrive at a more accurate technique.

This article, again brings me back to the unit on DNA (arguably the most interesting unit). I remember delving into the subject a little on my own when the question of aging came up and reading up on telomeres and just what they were. From what I remember, (and here's to hoping I don't butcher it) telomeres are structures at the end of our chromosomes that are like little protective caps. Each and every time our chromosomes replicate a little bit of those caps are worn off until our cells can no longer replicate like they used to. This means we can no longer heal and replace cells like our younger selves. Since every five years or so every last cell and atom of our body is replaced, replication is a constant and necessary process of life and without it we wither and lose functionality. This wearing-down of our telomeres is called senescence, but some creatures out there seem to exhibit no signs of senescence.The Immortal Jellyfish, the Rougheye Rockfish,. and even Crocodiles. A two century year old shark may sound intense but even more startling is the fact that crocodiles seem to have the potential to live for eternity. They show no signs of aging like other animals do and a seven year old Croc is as agile and fit as a 70 year old Croc. This is known as negligible senescence. Father Time cannot slay these ancient water demons, and they haven't changed one bit since the time of the Dinosaurs because they simply don't need too...they are already perfect, immortal, killing machines. Why you ask do we not see thousand year old Crocs? Because though time does not seem a factor in their demise, other Crocs can kill them, along with disease and starvation. Whats more terrifying is that with age, they keep growing. They grow bigger and stronger with each passing year and have the potential to live to pre-historic proportions. The only reason they don't is because to sustain their massive size, they need an equal supply of food. We see no "super-Crocs" because they simply cannot find sufficient food to match their necessary diet. Equivalent exchange.  Mother Nature, is the great equalizer.

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