One recent writer , whose FunTrivia handle is “Marcsana,” took the time to write quite a long critique of that first quiz. I decided to explore some of that critique here. As it’s long, we’ll go question by question.
A popular argument by creationists is that evolution could never have occurred because it is so unlikely. As one example, they have stated,' There are n! (n-factorial: n x n-1 x n-2 x...x 1) ways of an enzyme or DNA strand of n parts forming prebiotically. Since the smallest proteins have at least 100 amino acids, the chance of forming a particular enzyme prebiotically is at most 1divided by 100!, which is small enough to be disregarded.' What is wrong with this argument?
- Complex molecules don't form by chance alone
- Larger proteins have fewer amino acids
- The math is incorrect
- Enzymes can only be formed in living things
The correct answer is Complex molecules don't form by chance alone.
While this argument correctly demonstrates that no given protein could have come into existence all at once by pure chance, such a demonstration is irrelevant to current origin-of-life research. As Iris Fry points out, 'origin-of-life theories rely on various organizing principles, including selection mechanisms and catalysis, that are supposed to have limited and constrained the wide scope of possible prebiotic possibilities, thus constructing the scaffolding out of which the living arch eventually emerged'
The critique from Marcsana:
5. You have the following explanatory material: [repeats Fry quote above.] Actually, such a demonstration IS relevant to current origin-of-life research. Complex molecules, proteins, or anything else can't just evolve because it is mathematically impossible. Iris Fry says that origin-of-life theories rely on various organizing principles including selection mechanisms and catalysts...but never mentions one. Why? Because no known mechanisms or catalysts exist. And natural selection can only go so far. This has been observed operating with existing information in a species. Never has it been observed changing a species into another one.
I’ll deal with the “we have never observed one species changing into another” argument in another post, as it isn’t specifically related to the main question- can complex molecules evolve? It seems Marcsana says no- it’s mathematically impossible, and no known mechanisms or catalysts exist that can facilitate what Fry claims, that such organizing principles allowed the evolution of complex molecules from simpler ones. Unfortunately, Marcsana gave no references, scientific or otherwise, to support his claim. Therefore, it’s difficult to understand what is meant by “no known mechanisms or catalysts exist.”
Let’s look at the potential for evolution of complex molecules. For a moment, let’s suppose “no known mechanisms or catalysts exist” (although they do, and we’ll discuss that later.)
The chief mistake that creationists make is thinking that, just because one event has a tiny probability, that event could never occur. The problem with this line of thinking is that, rather obviously, the probability of an event occurring rises dramatically when you have more opportunities for that event to occur. To put this in plainer English- if I buy one lottery ticket and have to guess 6 random numbers to win a prize, I am very unlikely to ever win. But I cannot therefore state that the probability of winning the lottery is so infinitesimally tiny that no one will ever win. There are millions of people attempting to win and guessing at the numbers, and thus millions of trials. And, as we know, someone usually does win the lottery.
The same is true of forming molecules. Even if the chances of forming a particular molecule are very tiny in one trial, if there are billions upon billions of trials, the chances of that molecule being formed are very great.
There is an elegant explanation of this in “Lies, Damned Lies, Statistics,and Probability of Abiogenesis Calculations”
To quote this fine article briefly:
Okay, you are looking at that number again, 1 chance in 4.29 x 1040, that's a big number, and although a billion starting molecules is a lot of molecules, could we ever get enough molecules to randomly assemble our first replicator in under half a billion years?
Yes, one kilogram of the amino acid arginine has 2.85 x 1024 molecules in it (that's well over a billion billion); a tonne of arginine has 2.85 x 1027 molecules. If you took a semi-trailer load of each amino acid and dumped it into a medium size lake, you would have enough molecules to generate our particular replicator in a few tens of years, given that you can make 55 amino acid long proteins in 1 to 2 weeks [14,16].
So how does this shape up with the prebiotic Earth? On the early Earth it is likely that the ocean had a volume of 1 x 1024 litres. Given an amino acid concentration of 1 x 10-6 M (a moderately dilute soup, see Chyba and Sagan 1992 ), then there are roughly 1 x 1050 potential starting chains, so that a fair number of efficient peptide ligases (about 1 x 1031) could be produced in a under a year, let alone a million years. The synthesis of primitive self-replicators could happen relatively rapidly, even given a probability of 1 chance in 4.29 x 1040 (and remember, our replicator could be synthesized on the very first trial).
Now let’s get back to the claim that “no known mechanisms or catalysts exist.” Not so. In fact, the scientific literature on this subject is overwhelmingly large and complex. There are two major theories for the mechanism of origin of complex organic molecules, and hundreds of experiments have been done and articles published on each one. One, often known as “genes first,” or “the RNA world,” deals with RNA, which can both store information and act as a catalyst for self-replication. As replicated molecules would have some mutations, selection would operate upon them. The second, known as “metabolism first,” or “the iron-sulfur world,” deals with the creation of organic materials in deep-sea hydrothermal vents. Let’s look at that hypothesis more closely.
In the ocean even today, deep-sea vents are areas of extreme chemical activity. In one type of vent, water warmed beneath the earth bubbles up through tiny chambers of iron sulfide. Each tiny chamber acts as a chemical reactor, as the iron sulfide surface provides a substrate for molecules to grow. One molecule that forms easily in such chambers is acetate, a vital molecule in many organic reactions. Living bacteria have an acetate-production mechanism almost identical to that which produces acetate in these vents. These tiny chambers also functioned much like cell walls, allowing chemical structures to be protected while they formed.
The chemistry of these reactions is quite complex, but here are some sources:
Jump-Starting a Cellular World: Investigating the Origin of Life, from Soup to Networks
The emergence of life from iron monosulphide bubbles at a submarine hydrothermal
redox and pH front
From geochemistry to biochemistry:
Chemiosmotic coupling and transition element clusters in the onset of life and photosynthesis
And this is only a tiny slice of the immense body of research surrounding just one of the mechanisms by which organic molecules evolved.
So, in closing, it is mathematically and scientifically possible for complex molecules to evolve, and several mechanisms have been shown to produce the proper conditions for such evolution to occur.