Octopus News

[elainegrey]

https://www.nytimes.com/2017/04/06/science/octopus-squid-intelligence-rna-editing.html

This is just fascinating, cephalopods (or, at least, the octopus/squid branch of that class) have been discovered to do extensive RNA editing, giving them access to much more complex protein building behaviors than most creature's far less dynamic

To quote the NYTimes: "natural selection seems to have favored RNA editing in coleoids, even though it potentially slows the DNA-based evolution that typically helps organisms acquire beneficial adaptations over time."

The first two extinction events:

* 439 Mya (Million years ago) Ordovician–Silurian Extinction
** "86% of life on Earth was wiped out."
** "Trilobites, brachiopods, and graptolites died off in large numbers but interestingly, this did not lead to any major species changes during the next era."

* 364Mya Late Devonian Extinction
** "75% of species were lost"

The ancestors of cephalopods "became dominant during the Ordovician period," that is 485.4–443.8 Mya -- before that first extinction event. It seems that octopii are pretty adaptable as they are -- physically changing shape, changing skin appearance, incredibly mobile. And now the genetics of the creatures seem to be pretty flexible and mutable as well.

My mind swirls with what ifs and curiosity: Surely we have lost cephalopod diversity with the extinction events. There's no reason to believe the most smart-like-human-smart creature lineages would have survived all extinctions. The cost of those extinction events to a slowly evolving lineage would be much higher than to us vertebrates. (And plants' capacity for diversifying genetics seems much more than animals' capacity) What if there hadn't been extinction events? What would the apex of cephalopod evolution be like then?

Comments

[randomdreams]

I wonder if you can get a good civilization in a short-lived species.

[elainegrey]

I was reflecting on how alien decentralized thinking is to humans -- so used to this precious grey matter in our skull-safe. There was some other article about the decentralized nature of octopus arms -- the central brain doesn't trigger all the motions but triggers other neurons in the arm to set the arm in motion -- the arms aren't centrally coordinated.

Perhaps with such a distributed neural system, the sense of identity would not be the same as ours, where the individual is a single unit.

What would we accept as defining a civilization in such an alien pattern of cognition. We don't often talk about bee's having civilization (intriguing 1849 title at https://www.scientificamerican.com/article/is-the-bee-the-pioneer-of-civilizat/# ) although we have some recognition of the alien (and generally depicted as somewhat repulsive) concept of a hive mind. Those depictions still focus on a centralized identity. (And i recognize boundaries are property of the concept of identity.)

"Civilization" is an emergent property of some critical number and duration of humans. http://americanbeejournal.com/comb-building-wax-deposition-cell-construction-emergent-properties/

I wonder if the function of what we recognize as civilization has an element of the time it makes to manipulate the environment. Bees work in wax which can easily be manipulated in the lifetime of a bee. Branching coral can grow 8 inches in a year - http://coral.org/coral-reefs-101/coral-reef-ecology/how-coral-reefs-grow/ Farming coral would be a challenge....

https://www.jstor.org/stable/1542771?seq=1#page_scan_tab_contents
This is interesting in that the nautilus (which doesn't necessarily have the RNA quirk) is longer lived and survives after reproduction.

So, maybe in all those mass extinctions there was a species that lived past reproduction like the nautilus. And if it lived in colonies it would be more exposed to risk of extinction due to catastrophic event, i'd think, than solitary and distributed creatures. The solitary nature of the remaining octopi may create the evolutionary pressure of reproduce and die.

(Sorry to keep going on....)