Phantoms in the Universe?

The Standard Cosmological Model has introduced in physics two new concepts that didn't exist before:

• Dark matter: It seems to be five times more abundant than ordinary matter, but we don't know what it is, what it's made of. We only know that it appears to be affected by gravity, and so far, its existence has been concluded in two different ways: a) By analyzing the rotational motion of galaxies, which seems to require that there is more mass in them than what we can see. b) By studying the cosmic microwave background radiation, which has served as the basis for adjusting the standard cosmological model.
• Dark energy: We have no idea what it is. Some speak of a fifth fundamental interaction (or force), the quintessence, which would join the four we know: gravitational, electromagnetic, strong, and weak. Others offer different explanations, none of which have received experimental confirmation. The hypothesis of its existence is supported by two observations: a) Analyzing the expansion rate of the universe, after the 1998 discovery that this rate is accelerating. b) By studying the cosmic microwave background radiation, which has served as the basis for adjusting the standard cosmological model.

Arguments against the theory of evolution

Drosophila melanogaster

Despite what I said in the last paragraph of my previous post, there are still well-intentioned people who oppose the theory of evolution (although this is very rare among biologists), and sometimes offer arguments to defend their way of thinking. I will consider some of those arguments here and offer my answers.

Answer: The claim that evolution has not been successfully reproduced artificially is mistaken. We have been doing this for thousands of years through artificial selection, which gave Darwin the idea of ​​natural selection. We have been doing it for decades in the laboratory in a controlled way, as this Wikipedia article explains: Experimental evolution. And this has been done not just with bacteria, which have a very short life cycle, but also with higher animals.

The theory of evolution, is it science?

In three previous posts (this was the latest), I wrote more or less the following words:

The scientific theory of evolution is strongly supported by data from other sciences, such as embryology, comparative anatomy, paleontology, biogeography, and molecular biology (DNA analysis).

Since, despite everything, there are still those who doubt the scientific nature of this theory, in this post I will expand on the previous paragraph, explaining in a little more detail the scientific data that favor evolution.

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.