evolution of consciousness (Introduction)

by George Jelliss ⌂ @, St Leonards on Sea, Saturday, July 29, 2017, 17:19 (208 days ago)

Came across this and thought of you:

https://www.theatlantic.com/science/archive/2016/06/how-consciousness-evolved/485558/

All sounds quite plausible to me.

--
GPJ

evolution of consciousness

by David Turell @, Sunday, July 30, 2017, 02:02 (208 days ago) @ George Jelliss

George: Came across this and thought of you:

https://www.theatlantic.com/science/archive/2016/06/how-consciousness-evolved/485558/

All sounds quite plausible to me.

We all appreciate your thinking of us and providing this very well done explanation of the evolution of the human brain. I don't think he hasn't given us a good explanation of consciousness, but has afforded a good description as to how we arrived at the state of being conscious and responsive. Well worth reading.

evolution of consciousness

by dhw, Sunday, July 30, 2017, 11:03 (208 days ago) @ David Turell

George: Came across this and thought of you:

https://www.theatlantic.com/science/archive/2016/06/how-consciousness-evolved/485558/

All sounds quite plausible to me.

DAVID: We all appreciate your thinking of us and providing this very well done explanation of the evolution of the human brain. I don't think he hasn't given us a good explanation of consciousness, but has afforded a good description as to how we arrived at the state of being conscious and responsive. Well worth reading.

I add my delight at hearing from you again, George, and for a change I agree with David. Good history, but absolutely no explanation of consciousness. The essence of the whole thing seems to me to lie in this section. A talking crocodile might say:

I’ve got something intangible inside me. It’s not an eyeball or a head or an arm. It exists without substance. It’s my mental possession of things. It moves around from one set of items to another. When that mysterious process in me grasps hold of something, it allows me to understand, to remember, and to respond.”

The crocodile would be wrong, of course. Covert attention isn’t intangible. It has a physical basis, but that physical basis lies in the microscopic details of neurons, synapses, and signals. The brain has no need to know those details. The attention schema is therefore strategically vague. It depicts covert attention in a physically incoherent way, as a non-physical essence. And this, according to the theory, is the origin of consciousness. We say we have consciousness because deep in the brain, something quite primitive is computing that semi-magical self-description.

There is no theory of the origin of consciousness here. Merely the author’s contention that the crocodile is wrong, and it’s all due to neurons, synapses and signals, which is the standard materialist explanation. He may be right, but nobody in the world knows how it works or how it originated.

evolution: development of neurons

by David Turell @, Tuesday, February 20, 2018, 22:25 (2 days ago) @ dhw

They are such complex cells, did they evolve or were they designed:

https://darwins-god.blogspot.com/2018/02/this-didnt-evolve-few-mutations-at-time.html

"Nerve cells have a long tail which carries an electronic impulse. The tail can be several feet long and its signal might stimulate a muscle to action, control a gland, or report a sensation to the brain.

"Early researchers considered that perhaps the electronic impulse traveled along the nerve cell tail like electricity in a wire. But they soon realized that the signal in nerve cells is too weak to travel very far. The nerve cell would need to boost the signal along the way for it to travel along the tail.

"After years of research it was discovered that the signal is boosted by membrane proteins. First, there is a membrane protein that simultaneously pumps two potassium ions into the cell and three sodium ions out of the cell. This sets up a chemical gradient across the membrane. There is more potassium inside the cell than outside, and there is more sodium outside than inside. Also, there are more negatively charged ions inside the cell so there is a voltage drop (50-100 millivolt) across the membrane.

"In addition to the sodium-potassium pump, there are also sodium channels and potassium channels. These membrane proteins allow sodium and potassium, respectively, to pass through the membrane. They are normally closed, but when the decaying electronic impulse travels along the nerve cell tail, it causes the sodium channels to quickly open. Sodium ions outside the cell then come streaming into the cell down the electro-chemical gradient. As a result, the voltage drop is reversed and the decaying electronic impulse, which caused the sodium channels to open, is boosted as it continues on its way along the nerve cell tail.

"When the voltage goes from negative to positive inside the cell, the sodium channels slowly close and the potassium channels open. Hence the sodium channels are open only momentarily, and now with the potassium channels open, the potassium ions concentrated inside the cell come streaming out down their electro-chemical gradient. As a result the original voltage drop is reestablished.

"This process repeats itself as the electronic impulse travels along the tail of the nerve cell, until the impulse finally reaches the end of the nerve cell. Although we’ve left out many details, it should be obvious that the process depends on the intricate workings of the three membrane proteins. The sodium-potassium pump helps set up the electro-chemical gradient, the electronic impulse is strong enough to activate the sodium channel, and then the sodium and potassium channels open and close with precise timing.

"How, for example, are the channels designed to be ion-selective? Sodium is about 40% smaller than potassium so the sodium channel can exclude potassium if it is just big enough for sodium. Random mutations must have struck on an amino acid sequence that would fold up just right to provide the right channel size.

"The potassium channel, on the other hand is large enough for both potassium, and sodium, yet it is highly efficient. It somehow excludes sodium almost perfectly (the potassium to sodium ratio is about 10000), yet allows potassium to pass through almost as if there were nothing in the way."

"Nerve cells are constantly firing off in your body. They control your eyes as you read these words, and they send back the images you see on this page to your brain. They, along with chemical signals, control a multitude of processes in our bodies, and there is no scientific reason to think they gradually evolved, one mutation at time.

"Indeed, that idea contradicts everything we know from the science. And yet this is what evolutionists believe. Let me repeat that: evolutionists believe nerve cells and their action potential designs evolved one mutation at time. Indeed, evolutionists believe this is a proven fact, beyond all reasonable doubt."


Comment: Hunter then goes on to dissect an evolution-science paper about how neurons evolved and demonstrates how it is filled with wishful thinking., not fact A neuron appears in evolution from no predecessors and had to be designed to be this complex.

RSS Feed of thread
powered by my little forum