Slimey Story Link

Scientists link our origins to slime
By PENNY FANNIN
SCIENCE REPORTER
Monday 6 March 2000

The discovery of a single-celled brown alga that lives in ponds has revealed a missing link in the evolution of life.

The alga's mitochondria (the energy-producing part of the cell) has been observed by Australian scientists dividing in a way previously only seen in bacteria (also a single cell).

Dr Peter Beech, of Deakin University's school of biological and chemical sciences, said mitochondria were vital in evolution, generating most of a cell's energy.

Cells are the structural units of most living organisms. They may exist as independent units or they may form tissues as in all plants and animals. It is generally accepted that mitochondria evolved from a bacteria that merged with a cell about a billion years ago. But, until now, scientists have been unable to find evidence that shows mitochondria divide in the same way as bacteria.

Then, Dr Beech, with colleagues from the University of Melbourne, discovered that the brown alga still used the bacterial system of mitochondrial division. The finding was published in the journal Science last month and Dr Beech has since found evidence of bacterial-like mitochondrial division in another primitive organism - a slime mould.

The importance of mitochondria to plants, animals and fungi cannot be overestimated. Without mitochondria, these organisms could not survive, Dr Beech said.

"This lasting endosymbiosis (the combining of the cell and the bacteria) allowed early cells to go on to become the animals and plants of today so, in a sense, our energy generation comes from ancient bacteria that have co-evolved with us."

Dr Beech said it appeared mitochondrial-containing cells had followed two branches of evolution. Where mitochondria had retained the bacterial form of division, the organisms had remained primitive. But in modern cells, such as those found in humans, more complex mitochondrial division had evolved. And were it not for this more complex form of division we could still all be slime moulds.

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Comment:
Yes, I see it clearly now. It appears mitochondrial-containing cells had followed two branches of evolution!

That's it! Where mitochondria had retained the bacterial form of division, the organisms had remained primitive. Here that - primitive!

But in modern cells, such as those found in humans, more complex mitochondrial division had evolved. Blast it! Obviously far too much evolvement for some. That explains why more complex form of division still makes some be like slime moulds...hehehe...

Yup! Clear as a bell. It rings true to forum evolution, which can be traced right back to the origin of life - the humble mould.

Regards from Down Under bringing to you the latest contumacious cell of contention...

-- Pieter (zaadz@icisp.net.au), March 06, 2000

Answers

Pieter,

I think I have several living relataive that are still in the mitochondria stage :^)

Did it finally cool off down there?

-- Jim Cooke (JJCooke@yahoo.com), March 06, 2000.

Jeez - that's supposed to be "relatives" - I may not be far from the mitochondria myself....

-- Jim Cooke (JJCooke@yahoo.com), March 06, 2000.

G'Day Jim,
Yup, gentle weather and warming up to hot later this week. Lots of water everywhere in the north but buggerall down here in deepest purgatory. I'm told Cairns and surrounds got 58 inches of rain during the past month or so....none here though.

tut tut, sorry about the omission in the above article that it really was posted in appreciation of this forum's stirling performance at my cerebral devolution. Hmmm, that doesn't sound quite right...now, where's my banana.

Regards,

-- Pieter (zaadz@icisp.net.au), March 06, 2000.