Archive: Titan’s Young Atmosphere, More
These articles from January 2002 still hold interest for us all. They include an exclusive insider report from JPL about problems believing Saturn’s moon Titan is billions of years old. They end with news about ion channels in cells that keep us alive.
Note: Some links may no longer work.
Why Does Titan Still Have an Atmosphere? 01/17/2002
Exclusive The world’s leading planetary scientists, gathered for a quarterly planning session at the Jet Propulsion Laboratory for the Cassini Mission to Saturn and Titan, discuss many topics. This reporter was conversing over lunch with a leading atmospheric scientist about the nature of Titan, target of the Huygens Probe riding along Cassini, which (hopefully) will make a soft landing on the surface in January 2005. [Note: it succeeded spectacularly.]
This individual, a key instigator and principal investigator of Galileo’s probe that parachuted into Jupiter’s atmosphere in 1995, explained that the evolution of Titan’s atmosphere is a problem; it should be long gone by now. Methane in Titan’s thick atmosphere provides enough greenhouse effect to sustain the nitrogen and other ingredients which rain down ethane, acetylene and other hydrocarbons onto the surface continually, forming a fluffy snow possibly a hundred meters thick or more. But unlike earth, Titan has no cycle to recirculate these ingredients, so why is the process continuing today?
Furthermore, solar radiation is eroding the methane space blanket. When enough methane has been depleted, the atmosphere will collapse, because the temperature will fall enough to condense out the nitrogen, carrying it and all the other ingredients down to the surface. Dr. Atreya put 100 million years as an upper limit on the sustainability of Titan’s atmosphere – only about one fiftieth of the assumed age of the solar system. He had no explanation for why Titan has such a dense atmosphere today, other than perhaps it formed recently by some unknown mechanism, and we are lucky to see it. When the reporter remarked that such an answer sounded like the same one the ring scientists give for why we see Saturn’s rings (which are also very short lived), he agreed, with a grin of chagrin.
100 million years is the upper limit; it could be far less. Whenever you are told the earth and universe are billions of years old, don’t just swallow it: ask questions. That “the earth is 4.5 billion years old” is one of those truisms that everybody knows because the Discovery Channel says so, but what is the evidence? Here is another case of a phenomenon that doesn’t fit. It’s not that scientists can’t find a way to fit anomalies into the timeline; the important lesson is that the timeline does not come from the data, but from the assumptions. Be bold and question the assumptions. Continue clicking the Dating Methods chain links for other examples of anomalies that cause difficulties for the evolutionary time scale.
Darwinists Question Bateman’s Principle of Sexual Selection 01/17/2002
A news feature in the Jan 17 Nature, “Sexual Stereotypes,” discusses the rethinking of ideas about behavioral biology and sex. In 1948, Angus John Bateman formalized a hunch of Darwin’s that evolution progresses by producing males that are aggressive and profligate while producing females that are coy and choosy. Bateman studied fruit flies and concluded that promiscuity is more advantageous for males than females.
Bateman’s principle was extended to the entire animal kingdom, even humans, and became accepted as a truism. Since the 1970s, however, dissenting voices have arisen. Now, even if agreeing with the principle in part, scientists see the idea as simplistic: “Today, behavioural biologists are finding evidence that the world of sex is more complicated than Bateman thought. It’s not that his principle is invalid, they say, but rather that it has been used to extend dated preconceptions about human sexual behaviour to the entire animal kingdom, sometimes to the detriment of scientific knowledge. … another example, perhaps, of the truth being obscured by nineteenth-century sexual stereotypes.”
Our Baloney Detector is beeping on analogy, extrapolation, personification, and glittering generalities. How many other Darwinian ideas could be described as simplistic, projections of human stereotypes on the animal kingdom, and detrimental to scientific knowledge? Even today, Darwinian “truisms” have provided a pseudo-scientific rationalization for all kinds of immoral human sexual practices (see the PBS Evolution TV series episode five, Why Sex? for a recent example).
Science cannot provide justification for promiscuity. Which animal model should man follow, the birds that mate for life or the bonobos that have group sex? Any sexual fantasy can find a counterpart in nature that either supports it or argues against it. Science can only observe, not command; it has nothing to say to our human moral and ethical requirements. We are persons made in the image of God, not of fruit flies. What God designs or allows for animals is His prerogative, but for humans, He commanded, Thou shalt not commit adultery. Consider whether that command is trustworthy before rationalizing your life choices on a Darwinian principle that tomorrow may be dismissed as a myth.
Wonders of the Salt Gate 01/17/2002
A paper in Nature 1/17/01 describes for the first time a detailed description of one of the cell’s chloride channels, complex pores in the cell membrane that allow negative ions like Cl– from table salt to pass through, but restrict others. (For a good layman’s summary and illustration, see this news release on the Howard Hughes Medical Institute website.) Thomas Jentsch describes this as another “spectacular breakthrough” by Roderick MacKinnon’s team. He opens with an explanation: “Ion channels are proteins with a seemingly simple task – to allow the passive flow of ions across biological membranes. But this process requires more sophistication than one would imagine. ”
The full text of the paper reveals these channels to be “amazingly different” than cation channels (those that allow positively charged ions), and are shown to be exquisite protein complexes with gates composed of negatively-charged tips (that would normally repulse chloride ions) that apparently swing out of the way to let the desired molecules in. The authors explain the importance of these chloride channels:
Potassium, sodium, calcium and chloride ions are used ingeniously by living systems in the performance of fundamental cellular tasks. Through the action of ion pumps, a large fraction of a cell’s metabolic energy is spent establishing transmembrane ion gradients. These gradients, through the action of ion channels, are used to produce electrical signals, activate signal transduction pathways, regulate cell volume, and mediate fluid and electrolyte transport. To carry out these tasks, an ion channel has to be selective, that is, permit only certain ionic species to flow through its pore.
The precise placement of charged ends of amino acids along the pore attracts the chloride ions down the channel, without being so attractive that the ions would bind to them and get stuck. Failure of these channels is implicated in some serious muscle and kidney diseases.
Some animals have such a multitude of these effective ion pumps, they can generate a powerful electric shock. Says Jentsch: “On the basis of elegant biophysical studies by Miller and White, who showed that the electric ray Torpedo contains large amounts of a peculiar anion channel, the first voltage-gated Cl– channel was cloned by my group in 1990. We named it ClC-0, as we assumed that it would found a family of Cl– channels. This turned out to be true: CLC channels are found in all kingdoms of life, with humans alone having nine different CLC genes.”
The electric ray can generate 200 volts. On another related front, EurekAlert reported the next day that the UMass scientists have found microbes on the bottom of the sea that generate electricity, and the Navy is interested in harvesting these microorganisms to create living batteries. See the original paper in the Jan 18 Science.
Speaking of protein families, two creationists writing in the TJ Technical Journal 2001 #3 (posted on AIG 16-Jan-02) illustrate how they make a powerful case for design and argue against a naturalistic origin.
Update 03/04/2002: Scientific American posted an interview with MacKinnon about how his team made its discovery, and how the potassium channel works. In passing, he comments, “…the cavity and these helices were just a marvelous arrangement that Mother Nature used to solve this problem, you know, as if a very brilliant engineer did it all. I think that was very satisfying to see.”
Update 12/30/2002: In a new paper in the 12/27/02 issue of Cell, MacKinnon describes how another type of potassium channel acts as a sensitive biological rectifier.
All the statements we made about the wonders of the Water Gate on Dec. 20 apply here, and then some. The cell membrane is covered with these specialized pores that have “selectivity filters” and gates to attract and conduct desired molecules in, but keep unwanted invaders out. All life has them, they are all extremely complex, and without them life could not exist.
Compare the above empirical facts with the stories evolutionists tell about the origin of a living cell. They usually describe some lipid membrane spontaneously assembling through electrostatic or hydrophilic attraction into a seamless bag. Inside are a few RNA nucleotides, amino acids, sugars, and other “building blocks of life” (hopefully without nasty oxygen or killer tar molecules doing their worst). But if the membrane is sealed, without the ability to perform active transport of needed ingredients to the inside or remove unwanted toxins to the outside, the primitive cell becomes a death trap. The molecules inside are all that evolution has to work on, like those old jokes about being trapped in a locked room with Hitler, Stalin, a lawyer and only two bullets. The situation is not going to improve. Even if by some inconceivable magical miracle something wonderful happened inside this infinitesimal subset of primordial soup, it would still be a death trap. Unless the protocell could divide into two identical copies, natural selection, that magic wand of Darwinism, would be powerless.
On the other hand, if the membrane were leaky, osmosis would dictate mindlessly that the leakage would go from higher concentration to lower concentration, the opposite of what a living cell needs. For instance, a cell needs to be able to import precious water when the environment around it is drying up, but osmosis would guarantee the reverse, desiccating the poor cell. For these reasons, the simplistic evolutionary models of primitive membrane formation by spontaneous attraction of molecules are unrealistic. The observations show that all living things, even the most primitive, already have entire families of these sophisticated gates to control what goes in and out of the cell. There are no simple-to-complex intermediates known, and it is unlikely any could even be conceived that would give rise to working active transport without a host of genes and proteins controlling the construction and operation of these highly specialized and effective mechanisms.
MacKinnon’s paper only mentions evolution twice. For example, “Thus, it would appear that evolution of the channel has resulted in partial charges to stabilize a Cl– ion and still permit rapid ionic diffusion rates.” Yet he fails to provide any plausible story how this could have happened by mindless processes; he basically just admits that it is an elegant arrangement.
So how would the Intelligent Design (ID) approach explain it? Evolutionists sometimes complain that ID or creationism simply gives up and says “God did it,” but that is a caricature. It is sufficient for science to describe the phenomenon including its information content (including the DNA software and protein construction toolkit) without specifying “who done it” (to use Eugenie Scott’s favorite vulgarism). Strictly speaking, empirical science cannot address the Who question, and for the purposes of a scientific paper like this, it is not necessary to concoct a story of how it evolved, nor stuff the facts into a naturalistic tale of origins. Science did not “grind to a halt” just because these authors omitted an explanation for the origin of chloride channels. On the contrary, it is the belief that there is design (information adapted to function) in the world that has propelled science forward, and continues to do so today. That is why Intelligent Design is good for science. Scientists do well when just uncovering amazing examples of intelligent design like this one. Evolutionary storytelling is forced, incredible, superfluous.