Posted on 09/22/2018 9:37:26 AM PDT by ETL
Did the octopus evolve its unique intelligence by playing fast and free with the genetic code? Elizabeth Finkel investigates
-BIG snip-
Some 400 million years ago, cephalopods – creatures named for the fact that their heads are joined to their feet – ruled the oceans. They feasted on shrimp and starfish, grew to enormous sizes like the six-metre long Nautiloid, Cameroceras, and used their spiral-shaped shells for protection and flotation.
Then the age of fishes dawned, dethroning cephalopods as the top predators. Most of the spiral-shelled species became extinct; modern nautilus was one of the few exceptions.
But one group shed or internalised their shells. Thus unencumbered, they were free to explore new ways to compete with the smarter, fleeter fish. They gave rise to the octopus, squid and cuttlefish – a group known as the coleoids.
Their innovations were dazzling. They split their molluscan foot, creating eight highly dexterous arms, each with hundreds of suckers as agile as opposable thumbs. To illustrate this dexterity, Mather relates the story of a colleague who found his octopus pulling out its stitches after surgery.
But those limber bodies were a tasty treat to fish predators, so the octopus evolved ‘thinking skin’ that could melt into the background in a fifth of a second. These quick-change artists not only use a palette of skin pigments to paint with, they also have a repertoire of smooth to spiky skin textures, as well as body and arm contortions to complete their performance – perhaps an imitation of a patch of algae, as they stealthily perambulate on two of their eight arms.
“It’s not orchestrated by simple reflexes,” says Roger Hanlon, who researches camouflage behaviour at the Marine Biological Laboratory in Woods Hole, Massachusetts. “It’s a context-specific, fast computation of decisions carried out in multiple levels of the brain.” And it depends critically on a pair of camera eyes with keen capabilities.
It takes serious computing power to control eight arms, hundreds of suckers, ‘thinking skin’ and camera eyes. Hence the oversized brain of the octopus. With its 500 million neurons, that’s two and a half times that of a rat. But their brain anatomy is very different.
A mammalian brain is a centralised processor that sends and receives signals via the spinal cord. But for the octopus, only 10% of its brain is centralised in a highly folded, 30-lobed donut-shaped structure arranged around its oesophagus (really). Two optic lobes account for another 30%, and 60% lies in the arms. “It’s a weird way to construct a complex brain,” says Hanlon. “Everything about this animal is goofy and weird.”
Take the arms: they’re considered to have their own ‘mini-brain’ not just because they are so packed with neurons but because they also have independent processing power. For instance, an octopus escaping a predator can detach an arm that will happily continue crawling around for up to 10 minutes.
Indeed, until an experiment by Kuba and colleagues in 2011, some suspected the arms’ movements were independent of their central brain. They aren’t. Rather it appears that the brain gives a high-level command that a staff of eight arms execute autonomously.
“The arm has some fascinating reflexes, but it doesn’t learn,” says Kuba, who studied these reflexes between 2009 and 2013 as part of a European Union project to design bio-inspired robots.
And then there’s their ‘thinking’ skin. Again the brain, primarily the optic lobes, controls the processing power here. The evidence comes from a 1988 study by Hanlon and John Messenger from the University of Sheffield. They showed that blinded newly hatched cuttlefish could no longer match their surroundings.
They were still able to change colour and body patterns but in a seemingly random fashion. Anatomical evidence also shows that nerves in the lower brain connect directly to muscles surrounding the pigment sacs or chromatophores.
Like an artist spreading pigment on a pallet, activating the muscles pulls the sacs apart spreading the chromatophore pigments into thin discs of colour. But the octopus is not composing a picture. Hanlon’s experiments with cuttlefish show they are deploying one of three pre-existing patterns – uniform, mottled or disruptive – to achieve camouflage on diverse backgrounds.
As far as detailed brain circuitry goes, researchers have made little progress since the 1970s when legendary British neuroscientist J.Z Young worked out the gross anatomy of the distributed coleoid brain. Escaping Britain’s dismal winter for the Stazione Zoologica in balmy Naples, Young’s research was part of an American Air Force funded project to search for the theoretical memory circuit, the ‘engram’.
“They were ahead of their time,” says Hanlon, who experienced a stint with Young in Naples. Nevertheless they were limited by the paucity of brain-recording techniques that were suited to the octopus.
It’s a problem that has continued to hold back the understanding of how their brain circuits work. “Is it the same as the way mammals process information? We don’t know,” says Ragsdale.
-BIG snip-
Did you go to the link? It was a very long article.
Take a planet with no life, give it 400 million years, and you will still have a planet with no life.
It lives on a diet of calamari.
They do say you are what you eat
Does Joey Hairplug have blue hands because his ticker is running at 50% volume or is most of his blood pooling somewhere else?
So how long ago did He create the Earth?
My apology....did not read the article...did read it after you pointed it out...I ignorantly assumed you had snipped out gist of the article. Maybe title should be..
WHY IS OCTOPUS SO SMART....NEW STUDIES INDICATE DYNAMIC COMPLEX GENETIC/PROTEIN/STRUCTURE BRAIN FUNCTIONALITES.
Still...repeating an unobserved history does not shed any light as to how or why. Regards.
It was a really long article. I didn't know which part or parts to excerpt.
Lol! Sorry! Posted that to the wrong thread.
I’m sorry. That’s not allowed.
It (post 30) was meant for this thread...
They Made It! Japan’s Two Hopping Rovers Successfully Land on Asteroid Ryugu
https://www.freerepublic.com/focus/chat/3689757/posts
I think that Bishop Ussher placed it at 4004 BC. Of course, he couldn’t prove it.
Smoked octopus.....yummmmm.
“In the beginning, God created the heavens and the Earth...” You have knowledge of when the beginning was? Please share.
You are right. “In the beginning God created the heavens and earth.” Genesis, chapter 1, verse 1. But wait, there’s more! (Surely, though, you are so wise you already know this.) The first chapter of Genesis in the Bible describes the first seven days of earth’s creation. On the sixth day, God created man. We know him as Adam.
Later in the Bible, you can read the genealogy of Jesus, back to Adam. Jesus lived in the form of man and walked our earth just over 2,100 years ago. He still lives today, but that is for another discussion.
Thus, since we know the genealogy of Jesus, back to the beginning of time and earth as we know it, we also know that the earth is not 400,000 million years old. Thousands of years, yes. Millions, no.
Hope this helps. God bless you and your family.
Open the thread and see my reply to gundog. That should help with the answer you seek. God bless you and your family.
Are you mocking the idea of when God created, or if God created?
But can it disguise itself as a plate of calamari?
You imply that I’m mocking one or the other. In the first case, the when of things would seem to hinge on the calendar used. Solar? Biblical lunar calendar? Do I buy the 4004 BC date? No. Is that mocking anything? I don’t believe so. As to the if of it, let’s just say that here it is, and not quarrel about how it got here.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.