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Single-Celled Species' Genome As Complex As Ours?
An anonymous reader writes: "A new paper reports on the sequencing and analysis of the genome of a single-celled species known as Tetrahymena thermophila. This ciliate (like the Paramecium people look at in school) has some 27,000 genes, or nearly as many as humans. And despite existing as a single cell, this spcies encodes fantastic complexity and unusual features. For example, it has a primitive immune system that prevents the invasion of foreign DNA. Also, it is able to cordon off its germ cell lineage much as humans do with sperm and eggs. But Tetrahymena does this by having two nuclei within each cell, with one of the nuclei being held in reserve for sex. Basically, this species uses its genome complexity to function like a single celled chameleon, changing its shape and its properties in response to the changing environment. For example, when a new nutrient shows up in its neighborhood this species can build a kit to suck the nutrient in, degrade it, and turn it into cellular biomass quickly. Thus whereas humans use their genomic complexity in part to create a stable environment for the body, this species simply uses a genomic swiss army kit to make do with whatever environment it encounters."
Hot.
> when a new nutrient shows up in its neighborhood this species can build a kit to suck the nutrient in, degrade it,
I like where this is goin'.
> and turn it into cellular biomass quickly.
Giggity giggity goo!
Tetrahymena are non-pathogenic free-living ciliate protozoa. They are common in fresh-water. Tetrahymena species used as model organisms in biomedical researches are T. thermophila and T. pyriformis.
http://en.wikipedia.org/wiki/Tetrahymena
Wincopy
The number of genes is not necessarily an indicator of sophistication. Also I should point out that as you allude to in your sarcasm, we humans are not the most sophisticated at all biological functions. For instance, the human eye is a much less sophisticated device than the eyes of other creatures such as birds, turtles and even many fish species who see in many more "channels" than we do with greater color discrimination (and they can often fix their retinas when damaged unlike us who suffer when AMD or retinal degenerative diseases hit us).
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Well, the main problem is the public perception that evolution produces "superior" species. This is rooted in a 19th century mentality that held to a notion that there were "upper" and "lower" life forms (which incidentally is a view that predates natural selection by a good many years, and is arguably not confined to the 19th century). When you talk about the views held by the average non-scientist regarding evolution, the most common perception is "survival of the fittest", with the implication that those that survive are somehow better objectively.
In actuallity, survival of the fittest implies fittness for a certain environment only. To borrow someone else's analogy, you can have the best gills in the pond and you'll still die off with the rest if the pond dries up.
The problem is really the human ego; we have an enourmously hard time accepting the idea that humans aren't innately special. We're intelligent, certainly, and we're unique, but then again every species that has a highly specialized survival strategy is unique.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
I feel it's worth pointing out that no where in the Origin of Species does Darwin discuss human/great ape/primate evolution. I'm not even certain he used the word "evolution", but don't quote me on that. Also, no true evolutionary biologist has ever said that humans descended from monkeys. It's that whole common ancestor thing. Lot's of branches, not straight line.
You do realize that the quote didn't say "organism", right? It specified "organ", which is a major difference in biology. Organs have pretty much zero to do with gene count, and in any case single celled organisms don't really have organs in the normal sense of the word.
What Darwin was saying was essentially that if an organ were encountered that could not have developed incrementally, then that would disprove his theory. People have tried to show that the eye meets this criteria, but we now know that light sensing organs can develop incrementally. Wings have also been brought up as a potential arguement, but are counteracted by examples of wing-like structures that serve some intermediate purpose other than flight.
Plus, gene count does increase incrementally, so even if Darwin had used the word organism, your answer would still be "no". Gene count is really pretty irrelevant as a measure of complexity, and in any case is easy to increase slowly over time with mutation.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
A creationist-friendly way to segue into evolution (I've seen this done, it works in most cases):
1) Start with an explanation of what science is. At its core, science is the ongoing effort to understand our world and the universe around it, how it works, and how it came to be. Specifically, science is intended to look at the world impartially and judge it only on proveable, repeatable observations. Science is the practice of observing facts and forming opinions based solely on those facts.
2) Define a scientific theory. It's not "just a guess". A true theory is supported by all the available facts, and can be used to predict further observations. When a theory is proven wrong, it is either modified (as evolution has been many times) or thrown out entirely.
3) Explain the basics of evolution. Point out that it describes a system of nature, and not just an order of progression. The theory of evolution is not the idea that man evolved from monkeys. The idea comes from the theory, but is not an integral part of it. Evolution at its most basic level is simply stated as "life changes".
I've put it this way before: Would you agree that every generation of humanity is somehow different than the last? That with each generation, some individuals never reproduce and some are far more successful (have more kids) than others? Does that not change the gene pool for the entire species? Every generation, the gene pool changes a little bit. When those changes are cumulative, that's evolution.
4) If the subject comes up, address the fact that evolution has never been meant as a direct challenge to any faith or belief. It is simply the best model for explaining the scientific observations available. It can be contradicted tomorrow, should sufficient observations be made.
120 characters for a sig? That's bloody useless.
My criteria for "better" is the ability to set criteria for "better." Therefore I'm better than a bacteria. But maybe the bacteria have better criteria.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Come on, it's called "Intelligent" design, not "Frickin' Genius" design. The guy had like six days in which to do it all, of course he had to cut corners. What, do you think he's omniscient and omnipotent or something?
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton