Viruses May be the Precursors of All Life

steveha writes "The cover story for this month's Discover magazine tells of a recently discovered gigantic virus, Mimivirus, that has blurred the lines between viruses and bacteria, and spurred speculation that viruses could be the reason life evolved past single-celled organisms." From the article: "This is striking news, especially at a moment when the basic facts of origins and evolution seem to have fallen under a shroud. In the discussions of intelligent design, one hears a yearning for an old-fashioned creation story, in which some singular, inchoate entity stepped in to give rise to complex life-forms--humans in particular. "

Re:Virii need cells

[Miraba]

If you RTFA, you'd see this:

Mimi's outsize complement of genes--so large that the virus is tantalizingly close to being an independent organism--suggest to many scientists that Mimivirus underwent reductive evolution early on and shed some of its genome, including the genes necessary to replicate on its own.

In other words, Mimi suggests the possibility that virii are descended from cells.

Re:The solution to the chicken & egg problem..

[dcapel]

Except for the fact that Unix long predated Windows, it just constantly screws itself over in various ways.

Re:Here we go again...back 2 school

[micromuncher]

While I find the idea that life originated from some primordial soup mix to be distasteful at best and downright inconceivable at worst...

Doesn't everyone in biochem201 do Miller's experiment?

http://www.chem.duke.edu/~jds/cruise_chem/Exobiolo gy/miller.html/ [duke.edu]

The unfortunate thing about the skeptics is that they seldom want to take into account 1) time, and 2) chaos.

Re:Well

[steveha]

Nice of the poster to inject a controvertial personal view in the end of his submission for all of us to flame about.

Hi, I'm steveha. The poster.

For the record, here is the story submission exactly as I submitted it:

The cover story [discover.com] for this month's Discover [discover.com] magazine tells of a recently discovered gigantic virus, Mimivirus, that has blurred the lines between viruses and bacteria, and spurred speculation that viruses could be the reason life evolved past single-celled organisms.

Please note that I didn't put any personal views there.

Please also note that Zonk did not put words in my mouth. He put my summary in double-quotes, and then after the double-quotes he put some additional stuff from the article. He edited my link references but did not edit my words at all.

steveha

Re:Submitter misplaced the focus...

[steveha]

it's too bad the focus of the submitter was on the Intelligent Design snippet

Hi, I'm steveha. The submitter.

Please read this:

http://slashdot.org/comments.pl?sid=178821&cid=148 22486 [slashdot.org]

steveha

Viruses without hosts?

[JourneyExpertApe]

Don't all extant viruses require hosts to replicate? How could viruses be the precursors to prokaryotes? If they existed before cells, wouldn't they, by definition, not be viruses?

Disclaimer: IANAMicrobiologist

Good that you ask

[leehwtsohg]

What is referred to as "the theory of evolution" consists of several parts. First of all, common descent - i.e. that the different species that live on earth (or lived on earth in the past) have common ancestors. They did not appear independently, but instead descended and changed from that common ancestor. The theory does not specify if there was just one common ancestor, or several ancestors (i.e. that life might have originated several times). Currently evidence points at one common ancestor, with no good understanding of where to put viruses.
This theory had already many opportunities for being disproved. For example, if it had turned out that the DNA of one species has no resemblence to very close species - so for example, if the DNA of a marsupial rat was closer to that of a regular rat then it is to a kangaroo. Or if the genetic code of species would be a patchwork of pieces assembled from other species, taken almost without change, and not according to a pattern of common descent. It is amazing that the DNA, totally unknown at the time of Darwin, shows almost exactly the same pattern of descent as can be inferred by looking carefully at the animals - i.e from taxonomy - even when one looks at parts of DNA that seem to have no function.
Fossil evidence provides another opportunity for the theory of common descent to be chalenged: if we discovered a bird in 2 billion year old rocks, it would be a serious problem for the theory of common descent.

Another part of the theory of evolution is how changes from one species to another happen. The idea of evolution by natural selection and random changes. Part of that theory is a mathematical theory, and can not be disproven. Just like you can not disprove that 7 is a prime number - if you accept certain axioms, then it follows from them. What is disprovable is whether the theory applies to the world - to the way species changed in the past. That, again can be disproved. Darwin provided one example - he said that if one would find even a single instance in which a feature of one species evolved for the sole benefit of anoter species, then his theory would be proven wrong. Thus, artificially selected species have many features that are only good for humans - increased fat content, wiered shapes and so on, which make the species they are in much less viable. If you found something like that in species that were supposed to have been naturally selected, it again would provide a serious chalange to the theory of evolution.
Another possible way of disproving the theory is if you found within the DNA of humans a single gene of a length of say 1000 bases (letters) (out of the 10^9 that we have) that does not appear to be similar to a sequence in any organism on earth. (Though it would be already an increadible challange if it did not appear in any closely related ape).
Or imagine the following experiment: take bacteria, and delete the gene for digesting a certain sugar. Grow them with that sugar for some time. If the gene suddenly appeared back, it would be a serious challenge to the idea that things change through random mutations.

Hey - that was almost on topic!