What is the theory of evolution?

Tree of Life

The theory of evolution, in its current form, asserts that the transformation of species (the evolution of life) depends on five factors:

1.      Spontaneous variations in the genome (mutations, genetic recombination, and other events that modify the genome).

2.      Spontaneous variations in the environment. This factor is often overlooked, as the environment is usually quite stable, although sudden changes sometimes occur that can have huge consequences.

3.      Inheritance, through which the variations that occur as a result of the first factor are passed on to offspring and are subject to the action of natural selection.

4.      Natural selection, which means that those individuals whose genome is best adapted to the environment will leave more offspring (at least statistically).

5.      The basic laws of the universe, which are currently represented by quantum theory and the theory of relativity.

Are we speciesist?

In chapter 6 of his book ¿Qué es la Antropología? (What is Antropology, 2020), Francisco de Paula Rodríguez Valls writes:

Human beings would be speciesist if they acted according to the logic of survival by using the power of his faculties in his own benefit. All the other species would do that, of course... Human beings are the only species that may not be speciesist by taking care of the entire planet. By putting their power at the service of the entire kingdom of life.

According to the Merriam-Webster dictionary, speciesism is prejudice or discrimination based on species, especially against animals. It can also refer to the assumption that humans are superior to other species.

This is a recently coined word, one of those neologisms associated with the ideology of political correctness, which insists that we shouldn’t upset anyone, neither with our actions, nor with our words, nor with our thoughts. Starting from a laudable anti-racist stance, they extended it to increasingly exaggerated and absurd situations (there are many examples), and in particular to all other animal species, based on the ideological premise that no species is superior to any other, which, as I have explained several times in this blog, is highly debatable.

Evolutionary convergence

Stephen Jay Gould

One of the most spectacular controversies to have arisen in biology at the end of the 20th century was that between two famous biologists: the American Stephen Jay Gould and the British Simon Conway Morris. The controversy began with the former's book, published in 1989, Wonderful Life: The Burgess Shale and the Nature of History, to which Conway Morris responded in 1997 with another book, The Crucible of Creation. As the subtitle of Gould's book indicates, both biologists based their work on the discoveries of the Cambrian fauna of the Burgess Shale (Canada), which I referred to in another post, and which was discovered and studied precisely by Conway Morris.

In his study, Stephen Jay Gould focuses in particular on the surprising and abrupt diversification that took place 550 million years ago and left its mark on the Burgess Shale fauna to argue that evolution is dominated by the effects of chance, so that, if we rewound the history of life and repeated the evolutionary process, the results would not resemble anything we have now. As a corollary, if there is animal life on other worlds, around other stars, it won’t resemble anything on Earth. And if there is intelligent life outside Earth, their physical appearance will not resemble ours.

Water and the origin of life

All living beings, from microbes to humans, live in water or contain water. All chemical reactions that take place inside cells are carried out in water.

Liquid water is an extraordinary compound, with strange properties. It has one of the highest specific heats of all substances. This means that when heat is added to or removed from a body of water, the temperature varies more slowly than in any other liquid. This is important for living beings, as water acts as an environmental stabilizer. Also, it is the non-metallic liquid with the highest thermal conductivity, so local temperature variations are balanced very quickly.

Most liquids contract when they solidify, but water is an exception. It has its maximum density at a temperature of 4°C. The density of ice is lower, 0.92 times lower, so ice floats on water. So, when the temperature drops, water freezes from top to bottom, while other liquids solidify from bottom to top. This also has important biological consequences. In polar seas and in fresh waters of cold regions, when the temperature drops below the freezing point, the surface layer of ice insulates the water below from the cold, so that it never freezes and the beings that live there can remain alive and active, despite the harsh environmental conditions.

The chemical composition of life in other worlds

Is it a coincidence that life on Earth is based on carbon? Is this the only element capable of becoming the basis for life? Could there exist, somewhere in the Universe, a type of life different from ours, whose chemical composition is not based on carbon? On what atom or group of atoms could a chemistry of comparable complexity to organic chemistry be built, in theory?

There are 91 different chemical elements on Earth. Others have been generated artificially in the laboratory, and it is suspected that they can be produced in small quantities inside a giant star that becomes a supernova, but their life is short, because they are very radioactive and disintegrate quickly, transforming into more stable elements. Therefore, the search can be reduced to the 91 natural elements. We will select from these those that meet the following two conditions, essential to be able to be the chemical basis of life:

1. They must be capable of establishing more than two covalent bonds with other atoms.
2. They must be stable. That is, they must have at least one non-radioactive isotope.

Rational and scientific inklings about God’s existence

In the previous post I mentioned that science does not provide proof of the existence of God, but it does give inklings. In a book I wrote, which was published in Spanish in 2013 with the title ¿Es compatible Dios con la ciencia? Evolución y Cosmología (Is God Compatible with Science? Evolution and Cosmology) I described a list of those inklings. Here I will summarize a few of them. The first three are scientific, the others are not.

1.      The universe is a physical object. During the 19th century, atheist philosophers denied that the universe is a concept applicable to a concrete object that exists outside our mind. The universe is usually defined as the set of everything that exists. According to those philosophers, such a set does not exist, since the concept of the universe is an invention of the human mind, which does not correspond to any physical object. Therefore, it would not be necessary to look for its origin (its cause) outside our mind. This argument was disproved in the 20th century: Einstein’s theory of general relativity leads to a cosmological equation that applies to the universe, which implies that the cosmos has real existence, that it is a physical object.

Scientific proofs of God’s existence?

Two French engineers, Michel-Yves Bolloré and Olivier Bonnassies, have published a best-seller entitled Dieu - la science - les preuves: L'aube d'une revolution (God - Science - The Proofs: The Dawn of a Revolution), where they claim that science has proven the existence of God. The book is interesting, because it contains many anecdotes and quotes from scientists, and some little-known facts. However, I do not agree with their approach, which is apparent in the title of the book.

Can science prove the existence of God? As I have said in this blog more than once, the answer to this question must be negative. The object of science is the study of the material world. But God is not in the material world, He is not part of it. Therefore, he cannot be an object of study by science. This means that science will never succeed in proving the existence of God, nor will it succeed in proving his nonexistence.

As I explained in another post, perhaps Pope Pius XII was tempted to think that science had proved creation, although it is suspected that Georges Lemaître, discoverer of the Hubble-Lemaître law and the Big Bang theory, dissuaded him, for the Pope, in a speech shortly after their interview, said this: science, while progressing by leaps and bounds, will never be able to answer the ultimate questions, such as the origin of everything.