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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."
The funny thing about Origin of Species is that everyone immediately was pissed that Darwin had the nerve to say that we are descendents of monkeys.
Then a few years later, people were amazed that a simple worm has 20,000 genes. <sarcasm> How could it be that such a simple lowly creature has so many genes? Isn't more better? How could humans be beat? Blasphemy! </sarcasm>
And now it's 'news' that a single cell's genome has as many genes as a human's! When will we learn that the number of genes doesn't mean 'more advanced' or 'better off'? If this single celled organism's environment caused it to evolve more genes but physically change (seemingly) very little, why are we surprised?
My work here is dung.
It sounds like kind of the X-Men of single celled organisms.
A most of you are aware, there is a lot of "junk" DNA mixed with genes. We're begining to learn that a lot of the "junk" is another form of coded instruction. Or to force fit an analogy for the Slashdot crowd, genes code for hardware, "junk" DNA codes for software. So equating the number of genes with the complextity of an organism is only part of the picture. Not as bad as equating the number of chromosomes with complexity (corn has more than humans, I believe). But still overly simplified.
The world is made by those who show up for the job.
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.
How much got screwed up by the Bible Genesis 1:27 "God created man in his own image."
Thanks to that phrase, people think humans are superior to all other forms of life. Everything else was put there for us to exploit. We don't have to live in any sort of harmony, it's all just for the consumption of us superior beings.
Don't get me wrong, I eat cows, pigs, and all that with the best of them. But I do that because I'm an omnivore, not because I'm superior to a fish.
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.
It's always seemed to me that there *is* an objective criterion for superiority in a species. Since we're judging superiority as fitness or the ability for a certain pattern (the genome) to continue propagating, then the superior species would be that one most able to overcome a greater variety of possible roadblocks to it's survival. To use your analogy, an amphibious fish, with watertight skin that can also breath air, would be objectively better by these criteria because it doesn't need the pond. It can live on land if need be.
In short, adaptability is what makes a species "superior". This is what has made homo sapiens the dominant large animal species on the planet - our intelligence has allowed us to adapt to damn near every (land) niche on the planet. Rats are a highly fit species for this same reason, as are cockroaches, and many fungi and microorganisms. All of these species are well-rounded and adaptable. (And by this criteria, this new species featured in TFA is likewise highly advanced). The one thing that I can see possibly giving mankind an edge up out of that group is our ability to radically change and even create environments around us, most notably including the ability to leave this planet of our own volition. (While some spores can survive in space, they couldn't just pack up and leave when the sun goes Red Giant on us all. We might be able to).
And since highly adaptable species are more fit to survive over longer periods of time, then evolutionary pressure *will* tend to select for them. And in that sense there is a sort of teleology to evolution: over time, as environments change back and forth and around to a variety of different extremes, the most flexible, adaptable, and generally well-rounded species will tend to outlive the rest. To survive in particular niches against competition from species specialized to those niches, they will have to become more capable in many areas as well; not simply jacks of all trades, but also aces of many.
You're certainly right that the old concepts of some sort of linear progression culminating in mankind are inaccurate. But that doesn't mean you have to deny any sort of progression, or any sort of objective criteria for discerning superiority or fitness between species.
-Forrest Cameranesi, Geek of all Trades
"I am Sam. Sam I am. I do not like trolls, flames, or spam."
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.
All current life on Earth has been around for the exact same amount of time, i.e., since the first "cell", whatever it was. The lineage has certainly split and evolved divergently over the eons since then, but really, even "primative" organisms, if they are in existence today, have been around for the same amount of time as we humans have. In a sense, therefore, it should not be so surprising to find organisms with as much complexity as humans! It certainly is interesting to see how many commonalities there are amongst species that diverged so long ago -- clearly some convergent evolution also occured along the way -- amazing how nature finds similar solutions to common biological problems.
The objective criteria you mention must take the organism's habitat into account. You know this, I know this, but the problem is that many other people don't know this. The phrase "survival of the fittest" without the qualifier is what most people understand evolution to be, as if there were some measure of fittness that wasn't relative and subjective. This in turn leads to all sorts of misunderstandings about how evolution works, the most disturbing of which can be seen in 19th century social darwinism.
Plus, it's worth noting that not all evolutionary progress pays off. To get back to your own counterpoint about amphibious fish surviving when the pond dries up, those same fish would be a less successful species right up until the point where the water based life dies. They'd probably be a marginal species that outlives the specialists by a stroke of luck.
This is where genetic diversity matters - you never know what sort of arraingment is going to work best in the future. Often the generalists outlive the specialists, and humans are definately in the specialist category (we're completely dependant on man-made tools to survive).
As for us humans, I would argue that our environment is a technological one, and that we only consider ourselves highly evolved because we're basing our criteria on ourselves. In other words, our survival strategy is toolmaking, so we're biased in favour of that strategy over any other. I don't think it's possible to look at what we've evolved for objectively, anymore than an individual can judge themselves impartially. And it's way to easy to get into circular reasoning.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
Yes, but most biological systems come at a price. To continue with the gills analogy, a fish with even better gills than the versatile fish could cause extiniction of the more adaptable fish. Adaptability is important, but in the short run may make no difference to other organisms that use their biological resources more directly to the current environment, its a balance of both.
To talk a bit more about humanity's being special, its in large part in the brain. I would wager that almost every other bioligical system we have is bested by others in the animal kingdom. The brain turned adaptability from hardware to software. With a brain that can reason, the long process of evoultionary selection is not so necessary for short term environmental changes. Some of the environmental changes can be compensated for be behavioral (software) changes. This gives our species orders of magnitude greater adaptability.
- The majority of the sensors on it are completely overwhelmed in moderate light conditions, and are only useful at dusk.
- The resolution is very poor in the receptors that work in colour, and the high-resolution ones don't work at high light levels.
- The connection to the is seriously underspec'd (by a couple of orders of magnitude. Someone put a decimal point in the wrong place on the Intelligent Designs, perhaps?).
- The compression used to make up for the previous deficiency has serious bugs. These include the inability to properly transmit certain shapes, and the lack of absolute colour information. I wonder if our Intelligent Designer also worked on NTSC...
- As a previous poster mentioned, the connector for the uplink is badly wired and obscures the sensor.
- Very poor design tolerances. Only about 20% seem to be manufactured without any kind of defect.
If you've looked at the human brain recently, you will note that a volume similar to that of the eyes is dedicated to bug-fixes and work-arounds for poor design of the eyes themselves.If the human eye is the best our Intelligent Designer can come up with, perhaps someone could point me in the direction of his Intelligent Bug-Tracking System.
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Great post. Other defects in the human body:
- Why are our (male's) balls so badly protected? Why aren't they inside our body?
- Why are our brains so prone to chemical imbalances causing depressions and such?
- Why are girls able to get pregnant before their body can succesfully go through pregnancy and have an healthy child?
The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
There is nothing in your post that a Creationist would disagree with. Define evolution as a "change in allele frequencies in a population over time" and you will find Creationists nod in agreement. Tell the creationist that natural selection plays a strong role in determining who survives, and thus the frequency of various alleles - again, you will have agreement. Commit the fallacy of equivocation, by changing the definition of evolution from above to 'all living things share a common ancestor' - and there you will get disagreement.
Creationists don't deny evolution when properly defined. They reject the Darwinist beliefs that all things share a common ancestor. When you define evolution in more than one way; demonstrate one definition as being true, then throw in another idea which goes by the same name (evolution), you are guilty of equivocation.
Many people are surprised that Creationists believe in evolution when defined as a "change in allele frequencies in a population over time". I've seen even greater surprise when I tell them that Creationists believe that natural selection takes place. This is *not* the area that they dispute. You would do well to define your own theory properly (not equivocate), and to understand that which you want to criticise.
-Why do the air and food passages cross in our throat? Making them totally separate from each other would prevent us from choking.
-Why is the biggest and most important nerve in the body intertwined with the bones in the spine? It should follow a separate and more protected path inside the body.
-Why do we have a single bone, the femur, in the thigh, but two separate bones in the ankle? These bones aren't redundant, breaking any one of the two makes one unable to walk, yet each of them is weaker and easier to break than the femur. Having one strong bone in the ankle would be a better design.
1. So why weren't the sperm engineered to resist heat?
2. How do you think anti-depressants work? Magic?
3. There are also many cases of the opposite. Which doesn't say much about the "intelligent design" process.
Anyway, this arguments are silly. The bottom line is - anyone will have a hard time proving (or even defending) that we were intelligently designed. At least, if you're trying to prove it to someone who is him/herself intelligent enough to think about what's being said.
The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F