Humans Descended From Cells Without Nuclei Or Walls [evo, con't]

Unisci ^ | 13 Nov 01 | Ellen O'Brien

[RightWhale]

By Ellen O'Brien Humans Descended From Cells Without Nuclei Or Walls

Research on components of the brain's electrical signaling system has answered a basic question about our human evolution, confirming scientific belief that we two-legged, computer-using creatures are descended from prokaryotes -- cellular organisms so primitive and simple that they exist without nuclei or cell walls.

The study, led by Zhe Lu, MD, PhD, an Associate Professor in the Department of Physiology at the University of Pennsylvania School of Medicine were recently published in the journal Nature.

The research by Lu and his colleagues focused on the structure and function of molecules called potassium channels, which are essential to how the brain works. When potassium channels open and close, they control the flow of potassium ions across cell membranes. The current contributes to the electrical signals in nerve, muscle and endocrine cells.

Scientists who study the brain's electrical signals have relied on a blue-print developed from functional studies of eukaryotic (neuronal) potassium channels and structural studies of prokaryotic (bacterial) potassium channels, based on the assumption that the two channels are essentially the same. However this assumption has recently been challenged.

Lu and his collaborators devised a project in which the pore of a prokaryote's potassium channel (the interior core of the channel) was substituted for the pore of a potassium channel in a euokaryote. The scientists found that the eukarotic channel continued to function essentially as it had previous to the substitution.

"This has very profound implications for evolution," Lu said. "It appears the potassium channels in advanced brains and hearts of mammals have evolved from something like this bacterial channel. So what we learn from the more easily studied bacterial channels can be directly applied to our understanding of potassium channels in human brains."

In the study, Lu worked with Penn colleagues Angela Klem, research specialist, and Yajamana Ramu, PhD. The work was funded by the National Institutes of Health. -

[RightWhale]

they exist without nuclei or cell walls

Do prokaryotes lack cell walls?

[Junior]

Bump for later inclusion in the Ultimate Resource ...

[Dimensio]

Research on components of the brain's electrical signaling system has answered a basic question about our human evolution, confirming scientific belief that we two-legged, computer-using creatures are descended from prokaryotes -- cellular organisms so primitive and simple that they exist without nuclei or cell walls.

I'm not sure that I like the word "confirming" here, it implies a certainty that is incompatable with science. Perhaps its intended meaning isn't as such, but I'd be more comfortable with the word "affirming" or "reaffirming".

Perhaps I'm just too touchy, but "confirming" to me means that it is established as absolute truth, but nothing in science is established as absolute truth.

[Senator_Blutarski]

Research on components of the brain's electrical signaling system has answered a basic question about our human evolution, confirming scientific belief that we two-legged, computer-using creatures are descended from prokaryotes -- cellular organisms so primitive and simple that they exist without nuclei or cell walls.

Actually, I think this refers to members of the Democratic Party.

FReepers are the direct work of the hand of God.

[rogers21774]

I like to think we descended from Heavan.

[Dimensio]

I like to think we descended from Heavan.

Hrmm, well, I have been likened to a fallen angel.

[lavaroise]

This has very profound implications for evolution," Lu said. "It appears the potassium channels in advanced brains and hearts of mammals have evolved from something like this bacterial channel.

It is not because the Sun is working like a fusion power plant that the fusion power plant evolved from the sun. These people are mixing science and biological functions with speculation on evolution. It's political non-sense.

[Fiddlstix]

Hrmm, well, I have been likened to a fallen angel.

ROFL
Well then, that makes two of us.

[Gumlegs]

Do prokaryotes lack cell walls?

My aunt kept her prokaryotes in a cage in the living room.

[911]

Check out this page from the MIT Biology Hypertextbook.

Prokaryotes have a cell wall composed of peptidoglycan, a single large polymer of amino acids and sugar. Many types of eukaryotic cells also have cell walls, but none made of peptidoglycan.

[lavaroise]

Do not smash prokaryotes, you might hurt the evolution of new beings.

[RightWhale]

That must be what they mean. Obviously a cell would have a boundary, and it might be called a wall no matter what the composition might be. Sagan's Origin of Life buddies were always trying to find a chemical process that would create that first cell boundary of the first cell.

[Gumlegs]

My good man, this prokaryote has joined the ranks of the no longer living. It has expired. It has gone. It is an ex-prokaryote!

[911]

That must be what they mean.

Or they could just be wrong. They equate "no cell wall" with "primitive", when in fact the opposite is true. All cells have cell membranes, but cell walls are present in bacteria (prokaryotes), fungi, and plants, and not in animals.

[RightWhale]

cell walls are present in bacteria (prokaryotes), fungi, and plants, and not in animals.

That is what I recall from Bio 101 many years ago. Much has changed in biology since then, such as the kingdoms, so I thought they might be using the terms in a different way.

[lavaroise]

My good man, this prokaryote has joined the ranks of the no longer living. It has expired. It has gone. It is an ex-prokaryote!

LOL! Next time tell that to a Democrat who hates you. As in "Don't hurt freepers, they are creatures in evolution. "

[RightWhale]

Thanks for the response. Yours is the kind of post that makes FR a keeper.

[Phaedrus]

Research on components of the brain's electrical signaling system has answered a basic question about our human evolution, confirming scientific belief that we two-legged, computer-using creatures are descended from prokaryotes -- cellular organisms so primitive and simple that they exist without nuclei or cell walls.

Utter nonsense - a bald assertion without foundation, and wrong.