Tree of Life.

Thread Starter

BR-549

Joined Sep 22, 2013
4,928
Not long after we started using DNA, it was suggested that we ought to redo the tree of life based on genetics. This was great, because it shows accurately how life forms are related. But it also revealed some humongous gaps in our understanding of life on this planet.

We were all taught basic biology, the different kinds of bacteria and viruses, plant and animal, etc.

Take a look at this fella.



It's called a bacteriophage. This is not an artist's rendition. It's a electron microscope image.

He is standing on the skin of a bacteria. He has a drill projection that comes out of that center column that punches thru the skin. That's quite a structure for such a small creature.

Imagine explaining it's function. I like to see a movie of it drilling.

This creature either grew from something smaller, OR was assembled by something larger. Our modern science calls this replication. I wonder.

Anyhow, this is the article. Don't be concerned with the un-familiar terms and the weeds. Read on and you'll get the point.

http://www.theatlantic.com/science/archive/2016/04/the-tree-of-life-just-got-a-lot-weirder/477729/
 

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Thread Starter

BR-549

Joined Sep 22, 2013
4,928
It has been said that DNA is a print, a schematic for to build the structures necessary for metabolism, growth, and reproduction of a cell/organism.

But the DNA of very small and simple bacteria and viruses have large and complicated DNA strands.

What else could all the DNA code be doing? The last I read about it, it seemed a small strand was able to produce a huge variety of proteins and other cell components. So easy it even seems secondary.

What if it turns out that DNA is also the cells' active operating system, taking care of sec. to sec. operations and processes?

How can such an evolved and sophisticated system be found in the most primitive and right on the edge of the definition of life, come to be?

Why doesn't the simple organisms have simple DNA?

Another mystery.
 

Marley

Joined Apr 4, 2016
502
Don't underestimate bacteria. They have been around for a very long time. They are far from "simple". Why do they need all that DNA?
A lot of it probably serves no purpose. It is "switched off". But it probably had a use in the evolutionary past. In fact, it my be of use in the future when the descendants of the bacteria encounter new conditions or threats.
 

Thread Starter

BR-549

Joined Sep 22, 2013
4,928
I had to take a few courses in order for a lab contract. It was nothing heavy, but it was an eye opener.

According to the Atlantic article, there could be over 50% of the zeomass of life, that can not be maintained or studied in the lab.

If that's anywhere near true, we have missed an awful lot of processes, cycles and energy flows.

" All the creatures we’re familiar with—the animals, plants, and fungi—are crowded on one thin branch. The rest are largely filled with bacteria.

And around half of these bacterial branches belong to a supergroup, which was discovered very recently and still lacks a formal name. Informally, it’s known as the Candidate Phyla Radiation. Within its lineages, evolution has gone to town, producing countless species that we’re almost completely ignorant about. With a single exception, they’ve never been isolated or grown in a lab. In fact, this supergroup and “other lineages that lack isolated representatives clearly comprise the majority of life’s current diversity,” wrote Hug and Banfield.

“This is humbling,” says Jonathan Eisen from the University of California, Davis, “because holy **#$@#!, we know virtually nothing right now about the biology of most of the tree of life.”
 

wayneh

Joined Sep 9, 2010
17,496
Take a look at this fella.



It's called a bacteriophage. This is not an artist's rendition. It's a electron microscope image.
The images weren't nearly so good back then, but that's the kind of thing that drew me into majoring in biochemistry in college.
 
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