# The Greatest Show from Darwin 13-randomness

-13- The influence of randomness

Anyway, most of the questions that arise concern the same thing. And in the experience with artificial breeding of E. coli, and in the relocation of Podarcis sicula lizards from island to island, and the evolution of the eye, turtle, and many others, everything rests on the pace of evolutionary transformations.

What is the actual evolutionary step? Are complex mutations possible in one generation, or did evolution take less noticeable steps somehow agreeing with natural selection?

Finally, why do some species evolve faster than others? Moreover, the difference in speed differs so radically that all sorts of unscientific doubts creep up involuntarily. Indeed, if the mechanism of evolution is the same for everyone and this mechanism is based on random mutation, then why is the randomness of the process so much different from others in some examples?

How wonderful that some scientists undertake to calculate the speed of evolution. So, for example, the evolution of the eye from a spot of photoreceptor cells was laid in less than 364,000 years, explaining that this is a pessimistic calculation in which one generation averaged equated to one year. A total of 364,000 generations, plus or minus, although rather a minus, since this is a pessimistic calculation.

Let me remind you: that "in general, several thousand genes are involved in the development of the eye." Roughly it turns out that a hundred generations were put on one successful mutation. This should give us hope and confidence in the future.

Probably, it is not worth reminding about the very well-known bacterium Escherichia coli in scientific circles, which took some 45,000 generations for two mutations. And this is under ideal Darwinian conditions. At a comparable speed, under the same conditions carefully created in the laboratory by the bacteriologist Richard Lenski and his colleagues, we will have to wait somewhere 350 million generations for some decent vision. And we can be completely calm in the fact that neither our children nor grandchildren will meet somewhere in a dirty alley face to face with some bacterium.

Nature under normal conditions, far from ideal, it took, according to calculations, a hundred generations for one successful mutation. Not twenty-two and a half thousand, like the bacteriologist Richard Lenski in the laboratory, and two orders of magnitude faster.

How realistic are such calculations? Maybe someone is tempted to count mutations in a discrete format: did a bad or a good one happen? In principle, it is true, since mutations can be either useful or harmful. However, the probability of a useful one is far from discrete.

So, if you take a dice, then the probability of any of the faces falling out is one in six. If you have a deck with thirty-two cards in your hands, then the card you have made will be on top of the deck with a probability of one/32. If you want to pohimichit, then the probability of choosing the right chemical element will be one hundred and eighteenth (except for those elements that will be unavailable).

Those who have tried to play dice know that a six may not fall out at all during the whole game. In reality, this probability rule works only when the number of attempts is close to infinity.

What, then, is the probability of a useful combination at the cellular level or in DNA? I can't even guess. I will focus only on one point. If we are talking about improving something that is available, then the probability can be calculated somehow. But if something new is created randomly, then the probability does not lend itself to any analysis at all.

Using the example of the same dice, what is the probability of the number eight or ten falling out if there are only six faces? I'm not saying that the probability of such an event is small. I'm just saying that in the real world, the probability of such an event defies any analysis.

Let's return to the book "The Greatest Show on Earth: Evidence of Evolution":

"Many of the problems that we encounter in the evolutionary argument arise only because animals are so imprudent that they evolve at different speeds, and even sometimes they can be so imprudent that they do not evolve at all."

The assumption that Dockins will immediately dispel all doubts remains only an assumption. It turns out that for him it is the same incomprehensible mystery of nature: "If there was a law of nature prescribing that the number of evolutionary changes should always be necessarily proportional to the elapsed time, the degree of similarity would accurately reflect the closeness of kinship relations.

In the real world, however, we must resist evolutionary sprinters, such as birds who left their reptilian roots standing in Mesozoic dust, and whose uniqueness in our perception was helped by the coincidence that all their neighbors on the evolutionary tree were killed by an astronomical catastrophe.

At the other extreme, we should not succumb to "living fossils" such as Lingula, which, in extreme cases, have changed so little that they could almost interbreed with their distant ancestors if only a matchmaking time machine could provide them with a date. Lingula is not the only known example of a living fossil. Others include Limulus, horseshoe crabs, and Coelacanths..."

Horseshoe crabs, coelacanths, Lingula, Limulus could interbreed with their ancestors who lived millions of years ago. How is this possible? And this despite the fact that our ancestors did not even look like monkeys at that time. To what do we owe the advancing pace of our evolution? Or what has slowed down the progress of horseshoe crabs and the company so much? Isn't it interesting to figure this out?

Good. What is evolution? According to Darwin's theory, evolution is a random mutation plus natural selection. It is more correct to put a minus sign here, since natural selection weeds out unworthy mutations. But this is, by the way, so as not to forget about simple mathematical rules.

So, is the mutation rate unpredictable?

Every graduate of a technical institute is familiar with probability theory. The foundations of this science were laid back in the Middle Ages, although they did not immediately acquire a strictly mathematical justification. But the research of Christian Huygens, published in 1657, and independently of him by Pascal and Fermat, published in 1679, introduced the basic concepts of the theory and discovered the first probabilistic patterns.

Random variables and the probability of occurrence of some event (even mutations) are the basic concepts of probability theory. According to probability theory, if we take a small sample or a short period of time, which is the same for our case, then the probability of a random mutation is little predictable. Within the framework of the history of the planet, we have an almost infinite period of time in megalions of years. In such a time range, any randomness is perfectly predicted by mathematical methods.

The number of mutations over a long period of time can be averaged equally distributed over the entire time scale. And the mutations themselves should quite predictably occur at approximately the same time intervals.

It is known that some external factors, such as radiation, can significantly affect the rate of occurrence of mutations. The cause may be the release of radioactive substances from accidents at nuclear power plants or from nuclear bombing. We will not be so scrupulous that we will take into account the last century in the great evolutionary process. We have enough of the previous hundreds of millions of years, which purely randomly led the planet to accidents of nuclear power plants, nuclear bombing and other "achievements" of human civilization.

One term of the evolutionary process has been sorted out. For a long period of time, it can be considered unchanged and to a greater extent a constant value for any living organisms.

As for the second term (or, as we noticed, the subtractor), it's even easier with it. Natural selection is the pressure of predators and the lack of food resources. This mechanism is designed to weed out harmful mutations and encourage beneficial ones.

Natural selection cannot increase the speed of evolution in any way. Except to slow down. In the history of the Earth there were periods of global cooling and other cataclysms that significantly complicated the life of its then inhabitants. Under such conditions, natural selection could inadvertently destroy those whose mutations were very useful. Fortunately, this excessive pressure was episodic, of course, if you look at the scale of the life of the planet.

In any case, natural selection does not condescend to anyone and exerts the same pressure on all living beings. Both random mutations and natural selection within the framework of Darwin's theory should set approximately the same speed for any branches of the evolutionary tree.

Each leaf of this tree stretches towards the sun, the branches lengthen and the tree itself grows. The lack of sun or moisture caused by drought or other natural cataclysm equally affects all branches and the entire tree as a whole.

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