Dark benediction

Walter M. Miller Jr.

Walter M. Miller Jr. was an American author of science fiction, known for a single book that has become a classic: A Canticle for Leibowitz, possibly one of the best science fiction novels of all time, at least among those in the apocalyptic sub-genre, which describes what might happen after a total nuclear war.

The novel is divided into three parts: In the first, Fiat Homo, the world is just beginning to recover from the disaster. As in the centuries following the fall of the Western Roman Empire, the Catholic Church takes the responsibility for saving what little remains of classical culture (ours) through the monks of an order founded by one man, Leibowitz, who before the nuclear conflagration was an electrical engineer. In the second part, Fiat Lux, several centuries have gone by, a new civilization has emerged and the world is entering a new Renaissance. In the third, Fiat Voluntas Tua, this civilization has reached its peak, materialism comes back, and history threatens to repeat itself. But this time Miller leaves a possible escape open: the colonization of the galaxy.

The phenomenon of man

Pierre Teilhard de Chardin

We know from experience that man has a mind and consciousness. It is also evident that animals seem to have more mental activities the closer they are to us. Thus, mammals have more minds that reptiles, reptiles more than fish, fish more than invertebrates (possibly excluding cephalopods). All animals except sponges have a nervous system, although some have very little: the nematode Caenorhabditis elegans has only 300 neurons. Plants do not have a nervous system, but they have some sensitivity and are able to move slowly. And when Antonie van Leeuwenhoek discovered microorganisms in the seventeenth century, no one doubted that these tiny creatures were alive. True, biologists have not yet agreed on whether viruses, even more tiny beings, are alive or not. I have written about this in another post in this blog.

How insect societies arose

Solitary bee (Megachile) and social bee (Apis)

Among the insect order Hymenoptera there are many species that live independently, but there are also many others who live together in societies. Social life has evolved several times, both among ants (all of which are social) and between bees and wasps, many of which live alone. This fact should be explained: why is social life so prevalent among these insects, and how could it have evolved? In other words, did it provide any evolutionary advantage? In which way?

In insect societies, most individuals renounce reproduction and dedicate their lives to care for the queen (the only member of the society who lays eggs) and for their brothers and sisters, while they are larvae. Normally there are at least two separate castes: those who are sexually active (male and female) and those who are not (usually asexual females). The differences between active and neutral females come from the type of food they receive during their larval stage.

Malthus’s mistake

Thomas Robert Malthus

Since the end of the eighteenth century, apocalyptic warnings as regards the unstoppable increase of the world population have followed one another. In 1798, Thomas Robert Malthus published An essay on the principle of population, as it affects the future improvement of society, with remarks on the speculations of Mr. Godwin, M. Condorcet, and other writers. This essay includes the famous quotation:

Assuming then my postulata as granted, I say, that the power of population is indefinitely greater than the power in the earth to produce subsistence for man.

Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will shew the immensity of the first power in comparison of the second.

Logical fallacies

Stephen Hawking

In the previous article I mentioned that advocates of materialistic scientism often fall in logical fallacies, but usually do not notice, probably because their knowledge of philosophy is not deep enough. Moreover, they often despise philosophy, not realizing that logic (which is a part of philosophy) aims to analyze the way we think, and that, without logic, science loses its supporting base. So, Stephen Hawking wrote at the beginning of his book, The Grand Design:

Philosophy is dead ... Scientists have become the bearers of the torch of discovery in our quest for knowledge.

And starting there, he proceeds to make philosophy in a popular science book.

In my discussions with supporters of materialistic scientism, I’ve often had to tell my opponents that they are committing a logical fallacy. Generally they are reluctant to admit it, but when I explain it in detail, they finally do (I guess, because usually the discussion ends there). By this I do not mean to imply that I never fall in logical fallacies, because we are all human, but at least so far, no one has shown me any. Of course, it is possible that I have fallen in them and the person who was debating with me did not notice.

On intelligence

In his book On intelligence Jeff Hawkins writes this:

Francis Crick wrote a book about brains called The astonishing hypothesis. The astonishing hypothesis was simply that the mind is the creation of the cells in the brain. There is nothing else, no magic, no special sauce, only neurons and a dance of information... In calling this a hypothesis, Crick was being politically correct. That the cells in our brain create the mind is a fact, not a hypothesis. We need to understand what these thirty billion cells do and how they do it.

Wonderful! On the one hand, he states that it is a fact, not a hypothesis, that the neurons of the brain create the mind. On the other, he accepts that we don’t know what they do, or how they do it. How does Hawkins know this for a fact, not a hypothesis? By infused knowledge? How was he able to detect that fact? Are there any arguments to support it? He gives none, he just asserts. Is this good science?

Einstein’s mistake

When Einstein formulated in 1915 his theory of general relativity, he soon applied it to the entire universe, deriving the following cosmological equation:

It is curious that this equation is identical to the equation that would result from Newton’s theory of gravitation. There is only one difference: constant k represents, in Newton’s case, the total energy of the universe; in Einstein’s case, its curvature.

Each term of this equation contains a universal constant. Besides k, G is the gravitational constant; L is called the cosmological constant, whose interpretation is not clear. Einstein initially thought he could eliminate this term by making L = 0, which simplifies the equation and makes it analytically solvable. Then he discovered that the solution, in that case, was a universe in constant expansion. Since he believed that the universe had to be stationary, he decided to assign the constant a critical value L = L_c, to make it be so.

More about the end of science

Science News, January 19, 2008

In a previous post I mentioned some inklings that seem to indicate that scientific development is decelerating. In this post I will focus on further evidence: the fact that most of the new discoveries being made in many sciences are almost always conditional. Rather than findings of fact, usually they just forecast possible findings that could be made in the future.

To show that this surmise may be true, I will consider a particular issue of the magazine Science News, one of the most prestigious among those engaged in high-level popular science. Specifically, I have taken the issue of January 19, 2008, which contains 18 news. Let us consider the titles or the first words, where I have enhanced those terms that indicate that the results of the investigation were provisional or tentative (unless you are really interested, you don’t have to read them all, you can skip to the last three paragraphs):

Dostoyevsky and the function of one variable

Fyodor Dostoyevsky

In his novel The devils (or The possessed, for there are two versions of the title), published in 1872, Dostoyevsky appears as a political prophet who displays a surprising knowledge of Communism and communists. In this book, 45 years before the fact, he predicted correctly that Russia would be the first country where Communism would win, an idea disregarded by Marx and Engels due to the lack of an industrial proletariat in that country. Let us listen to one of the characters in the novel:

We know that a mysterious finger is pointing to our delightful country as the land most fitted to accomplish the great task.

The communists in the book, the possessed, or the devils, have the same aims as their counterparts who triumphed in the Soviet Union, such as the elimination of religion. To reach their objectives, they propose two different procedures. Let us look at the words that Dostoyevsky puts in their mouths:

Darwin’s mistake

Charles Darwin

Consider the following paragraph by Darwin in The descent of man (chapter 5):

With savages, the weak in body or mind are soon eliminated; and those that survive commonly exhibit a vigorous state of health. We civilised men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we institute poor-laws; and our medical men exert their utmost skill to save the life of every one to the last moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution would formerly have succumbed to small-pox. Thus the weak members of civilised societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man.

It seems incredible that, after a lifetime devoted almost exclusively to meditate on his theory of evolution, Darwin made the mistake of applying it wrongly to humans, as is clearly demonstrated in the paragraph I have just quoted.

Inside Out

The materialist atheist philosophy has a problem: it cannot explain human free will, the existence of which has been a universal consensus among philosophers and individual human beings. So, they are bent on denying its existence. Is there an easier way to solve a problem that deny there is one? Thus they offer a number of theories to explain it away. I will cite a few:

• Free will is just an appearance. We are really the toy of our feelings (joy, sadness, fear, anger, disgust...). The Disney-Pixar film Inside Out could be an example of this philosophical stance.

We are not living in a simulation: a note on Nick Bostrom’s proposal

Simulation of the collision of two galaxies

In a paper published in 2003 [1] Nick Bostrom proposed the following reasoning:

A technologically mature “posthuman” civilization would have enormous computing power. Based on this empirical fact, the simulation argument shows that at least one of the following propositions is true:

(1)   The fraction of human-level civilizations that reach a posthuman stage is very close to zero;

(2)   The fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero;

(3)   The fraction of all people with our kind of experiences that are living in a simulation is very close to one.

Ikiru, or the power of abduction

A scene from Ikiru

Ikiru (To Live) is a great movie by Akira Kurosawa, one of the best two Japanese filmmakers of the mid-twentieth century (the other one is Yasihiro Ozu). Perhaps not as well known as Seven Samurai or Dersu Uzala, this film has many followers and its argument lends itself to curious considerations.

The protagonist, Kanji Watanabe, has been working for 30 years in the bureaucracy of the City of Tokyo. As the narrator says at the beginning of the film, in these 30 years he has not lived. Or in the words of Toyo, his young employee, he has behaved like a mummy. Then he learns that he suffers from stomach cancer and has less than a year to live. As I mentioned in another post in this blog, by 1952, the year the movie was released, a cancer diagnosis was equivalent to a death sentence. Watanabe discovers the value of life and tries to start living.After trying without success to drown his sorrow in pleasure, he decides to start a crusade for the sanitation of some land and the building of a playground. Although it costs him a huge effort, because the bureaucracy makes a tooth and nail resistance, he finally succeeds. The last fifty minutes of the film are devoted to Watanabe’s funeral, with several flashbacks showing his fight against the bureaucracy.

The mystery of too many variables

Standard theory of particle physics

We have now two great physical theories:

·         On one side, quantum mechanics, which applies primarily to very small objects (those scarcely affected by gravity), and is the basic tool for the standard theory of particle physics.

·         On the other, general relativity, which applies to very large objects (from the planets to the whole universe, those for which almost nothing matters except gravity), and is the main tool for the standard cosmological (Big Bang) theory.

Unfortunately, the two theories are not mutually compatible, so that physics is far from having resolved its outstanding issues. Moreover, these two theories depend on about forty independent variables. Many physicists think that they are too many. If it were true, it would mean that the configuration space of nature has about forty dimensions. If it is difficult to imagine a four-dimensional space, what about forty!

The sin of the scientist

Isaac Asimov

In an article published in 1969 with the same title as this one, Isaac Asimov argued that science should be subject to ethical constraints, and analyzed several cases in which a scientific discovery could be considered morally unacceptable. I consider here a few cases, not necessarily the same as those chosen by Asimov, and later will comment on his conclusion.

• The medical experiments with the Jews in concentration camps by Dr. Mengele and other Nazi doctors, or by the Japanese with their American prisoners. Even in such a blatant case, the perpetrators could find an ethical justification on their deeds, arguing that, as their victims were inferior beings who had no right to life, it was right to use them for experiments that could be beneficial to other human beings that enjoyed that right. It is an unacceptable justification, but they probably used it to silence their conscience.
• The two atomic bombs dropped on the Japanese cities of Hiroshima and Nagasaki at the end of World War II. This act of war killed over 200,000 non-combatant civilians. During most of Western history, including the first World War, this would have been considered unacceptable. The justification was that dropping the bombs saved the lives of thousands of soldiers, who would have died if the fighting had been prolonged. Is this enough, or are we again comparing the lives of two groups of human beings, some of which are considered more valuable than others? Anyway, Sergeant Leroy Lehman, who recognized Hiroshima before the release of the bomb, ended his days in a monastery.
• The same argument (that the lives of some human beings are more valuable than those of others) has been used in other circumstances. Sometimes, to increase the strength of the argument, even the human quality of the victims is denied. Some cases are obvious, both in history (slavery) and now (abortion).

First atomic bomb explosion in Alamogordo

In his article, Asimov concluded that there are cases where science has led to morally unjustifiable progress, and pointed at the use of poison gases as a war weapon whose sole purpose was killing human beings. It is noteworthy that the author of this discovery (Fritz Haber) was later awarded the Nobel Prize, not for poison gas, of course, but for other important findings in the field of chemistry (a process for synthesizing ammonia from nitrogen and hydrogen).

The same post in Spanish
Thematic Thread on Science in General: Previous Next

Manuel Alfonseca

The end of science

Servers at LAAS
by Guillaume Paumier
Licensed under CC BY 3.0
via Wikimedia Commons

In my previous article I wrote this: perhaps our scientific civilization won’t endure beyond this century. This is what I mean by the title of this article (the end of science), rather than the possibility that science is over because it has already discovered everything that can be discovered, which is very unlikely, as I pointed out in another post.

Science has been an integral part of our civilization for centuries, more than is usually believed, for scientific activity was already palpable during the Middle Ages. Isn’t it absurd to predict that such activity can be ended? How might this happen? Here I propose a few, far from exhaustive considerations:

The horizon effect

We are well aware of the horizon effect: as we walk towards the horizon, the horizon gets further away. In science sometimes this effect seems to apply. Let us look at a few examples:

Mycoplasma genitalium genetic map

• Synthetic biology: In 1960, producing living cells in the laboratory was predicted to be feasible by 1970. In 2015, Craig Venter (1) sees it feasible soon, perhaps by 2030. It is true that we have come very far, that great strides have been made, but the ultimate goal seems to be always at the same distance, or even a little further away. Moreover, the origin of life remains a mystery. The simplest being able to live independently (Mycoplasma genitalium) is very complicated, light-years away from the hypothetical first living being.

Surveys and statistics: opinions and facts

Henry Whitehead (1825-1896)

We tend to confuse the majority opinion with the truth. This is wrong, as expressed by Henry Whitehead:

Never fear forming a minority of one; majorities are usually wrong.

But sometimes the consequences drawn from public opinion are even more misleading than the opinion itself. In an article entitled Are we xenophobic? published in a Spanish high-diffusion newspaper on March 17, 2011, the author discussed the result of an official survey:

...Citizens believe that immigrants receive from the state...

lots more (30.8%) or just more (38.7%) than they contribute.

And he drew from this result the following comment:

Any sociological diagnosis would understand these figures
as a breeding ground for a reactionary and xenophobic social culture.
Saying the opposite is tantamount to denying a consistent reality.

Predicting social future: political correctness

2001, A Space Odyssey

As I discussed in a previous post, scientists are often wrong when they predict the future of science. Science fiction writers make mistakes too, especially when they are trying to predict technical advances. Consider the film 2001, A Space Odyssey, which got wrong almost all the developments proposed for that year. Fourteen years after the date in the title, we still don’t have a base on the moon, manned spaceships to Jupiter, artificial intelligence, or humans in hibernation.

We should remember Asimov’s third law of futurics, which states that predicting the social consequences of future scientific progress is more important than accurately predicting that progress. A SF story predicting cars, but not the parking problem, would not have been a good SF story.

In 1941, before Asimov formulated this law, Robert Heinlein correctly applied it in his short story Solution Unsatisfactory, which predicted the Manhattan Project, the atomic bomb, its use to end World War II and the subsequent nuclear stalemate between the great powers. Not bad, as an example of what you can do in a well-built science fiction story.

Predicting the scientific future

Man likes making predictions about the future. Scientists are human beings, therefore they make predictions about the progress to be expected in various fields of research during the coming years, decades and even centuries. These predictions are widely publicized by the media.

Are scientific predictions more likely to be satisfied than other predictions of the future? We might think so, since science is the most rational branch of human knowledge. What should we do to confirm or disconfirm this surmise? We should apply the scientific method to the predictions, i.e. wait until the scheduled time has come and check whether the predictions were fulfilled or not. Such studies are not usually done. Everyone is prepared to predict or to listen to predictions, but few bother to check if those anticipations actually came to happen.

There are a few egregious cases that many people remember. In 1956, the Dartmouth Summer Research Project on Artificial Intelligence, where the term Artificial Intelligence was coined, predicted that in less than ten years we would have computer programs capable of beating the world chess champion, or seamlessly translating between any two human languages. The total failure of this prediction is obvious: the first target came true 41 years later rather than 10, while the second has not been achieved after almost 60 years. As a result of this failure, research in artificial intelligence stopped for more than a decade and was not revived until expert systems reawakened interest in the discipline.

Questions for materialist atheists

Steven Weinberg

There is a website (10 questions Christians must answer) that offers 10 questions to believers in Christianity. If they consider and meditate these questions deeply, they are supposed to convince themselves that their religious beliefs are absurd, that the best they can do is convert to atheism. This website (and others like it) gave us the idea that these contributions are double-edged, as the same procedure can be used for the opposite purpose: one can also be skeptical towards materialism. Therefore we are proposing here a few questions and offer a link to the atheistic page to give the reader the chance to compare both approaches impartially and draw their own conclusions.

1.      Consider this assertion: Nothing exists but those things with which science can experiment. Do you believe this because of scientific reasons, or it is a dogma for you?

Is man just an animal?

Theodosius Dobzhansky

Modern biologists frequently say that man is not special, that we are just a species among many. Thus, for instance, Colin Tudge writes this:

Phylogenetically we are an outpost, a tiny figment of life, just as Earth is a cosmological nonentity that no other intelligent life-form in the Universe would bother to put in their celestial maps.

(The variety of life, Oxford University Press, 2000).

This is just the indiscriminate application of a pseudo-scientific dogma that few biologists would dare contradict, which can be expressed in one of the following equivalent ways:

• All species of living beings are equivalent; no one is superior to the others.
• There are no criteria that make it possible to compare the importance of different species.
• Man is not superior to chimps, ants, bacteria...
• Evolution has no direction.

Evolution and progress

Friedrich Nietzsche

In the late nineteenth century, many biologists and thinkers, atheists or agnostics, relied on Darwin's theories to build philosophical schools that combined the newly discovered evolution with the eighteenth-century idea of ​​progress, to assert that the history of life and man shows clear traces of indefinite progress, and to predict that such progress will continue indefinitely into the future.

Among the biologists who ascribed to these theories the best known are T.H. Huxley and Ernest Haeckel. The philosophers were many, each one giving rise to a school of his own, often incompatible with those of others: Karl Marx (Marxism), Herbert Spencer (social Darwinism), Auguste Comte (positivism) and Friedrich Nietzsche (nihilism) were the more influential. In their forecasts for the future of evolution, the last-mentioned was the most exalted and predicted that man would soon be succeeded and supplanted by a superior species, the superman.

Scientific fraud, a danger for science

Piltdown man

Fraudulent activity is not exclusive of politicians and the world of finances, though perhaps it is more widespread in those fields. It also affects scientists, who, like every human being, are prone to temptation and sometimes (surprisingly rarely) fall into it. The reasons are the usual: ambition, fame and the unbearable pressure to publish results.

The first thing we must do is find out what is fraud and what it is not. According to the criteria used in the United States, there are just two essentially fraudulent scientific activities: plagiarism and the invention or falsification of experimental results. The following activities are questionable, but not fraud: mistaking speculation with fact; incorrect use of statistical procedures; seeking approval after the fact for ethically controversial experiments. Finally, the following activities must not be considered fraudulent or questionable: judgment errors, differences of opinion in the interpretation of data, or involuntary errors in their analysis.

The invention of the genetic code

As is well known, the genetic code is the representation of the amino acid sequence of proteins by means of DNA strands. Now, the proteins of living beings are made of 20 different amino acids. However, there are only four different nucleotides in DNA. How can just four bases represent 20 amino acids?

With codons made of two nucleotides just 16 amino acids could be represented. As they are 20, two nucleotides are not enough: three must be used. Indeed, that is what life has done: each amino acid is represented by codons made of three nucleotides. The problem is, three nucleotides could represent 64 different amino acids, rather than 20 (21, considering that there codons mark the end of the string). What is the solution? Obviously, some amino acids must be represented by several codons (this is what is called degeneracy of the genetic code).

The four DNA nucleotides are made of a skeleton of sugar and phosphoric acid, combined with a nucleobase. In DNA there are four different bases:

• Two purines (P): adenine (A) and guanine (G).
• Two pyrimidines (Q): cytosine (C) y thymine (T).

The final anthropic principle and the antiChrist

Pierre Teilhard de Chardin

In their popular science book, The Anthropic Cosmological Principle, published in 1986, cosmologists John Barrow and Frank Tipler define three different anthropic principles:

1.      The weak anthropic principle or WAP (this was offered by Brandon Carter in 1973): the simple verification that the fact that we are here imposes certain restrictions on the universe, such as having lasted long enough for intelligent life to appear.

2.      The strong anthropic principle or SAP: the claim that making possible the emergence of intelligent life was a necessary requirement for the universe.

3.      The final anthropic principle or FAP: The claim that, once intelligent life has appeared in the universe, it cannot disappear.

Are we alone in the galaxy?

Enrico Fermi

In their famous book of hard scientific popularization, The Anthropic Cosmological Principle, published in 1986, the cosmologists John Barrow and Frank Tipler offer a proof that we are alone in the galaxy by means of a variant of the Fermi paradox (if there are any extraterrestrial intelligences in the Galaxy, why aren’t they here?) which can be summarized as follows:

1.      In 100 years we will have succeeded in creating life in the laboratory. Not just life, we will also be able to build a complete human being from its chemical components and information about the human genome, which can be stored in a digital memory.

2.      In 100 years we will have managed to build artificial intelligences as intelligent as human beings, able to replace us in any place and circumstance.

3.      Our current space technology allows us to reach a speed of 0.0003 c (where c is the speed of light). At that speed, a spaceship would take about 50,000 years to reach the nearest stars.

How eukaryotic cells arose

Examples of eukaryotes

The discovery that there are two main types of living cells (prokaryotes and eukaryotes) gave rise to a revolution in the way of classifying living things. Although (as usual) biologists do not agree on a single classification, the following one seems very reasonable:

1.      Empire prokaryote (bacteria). DNA free in the protoplasm.

a.       Kingdom eubacteria (true bacteria). They use acyl ester lipids.

b.      Kingdom archaea. They use isoprenoidal-ether lipids. They include sulphobacteria, methanobacteria and halobacteria.

2.      Empire eukaryote (cells with nuclei). DNA inside the nucleus. They have a cytoskeleton.

c.       Kingdom archaezoa (primitive eukaryotes). They have no organelles.

d.      Kingdom protozoa (advanced unicellular eukaryotes) with symbiotic organelles.

e.       Kingdom Fungi.

f.       Kingdom metaphyta (plants).

g.      Kingdom of metazoa (animals).

Why science can’t explain everything

The difficulty of explaining everything is not due to our mental weakness, but to the very structure of the universe. In recent centuries we have discovered that the fabric of the cosmos can be considered on several different levels. While the next level has not been discovered, what happens in the previous one cannot be explained, it can just be described. Consequently, for the last known level we can never have explanations, we can only have descriptions.

Let's look at a little history:

1. Eighteenth-century chemists discovered many new substances. Not knowing what they were, all they could do was describe them in catalogs of properties, but they had no explanation of those properties.

The v>c world

Albert Einstein

In 1967, Gerald Feinberg game the name tachyon (from the Greek tacus, fast) to hypothetical particles whose possible existence had been proposed five years before by other researchers. Tachyons would have a unique property: they always move at speeds greater than the speed of light. Their mathematical behavior would not infringe the limitations of the special theory of relativity, which prohibits bodies with mass reaching the speed of light. Unfortunately this would cause other problems.

The idea of ​​the possible existence of tachyons was embraced with joy by science fiction writers, for they seemed to make interstellar travel possible in a reasonable time. For this, the following procedure would be effective:

Sex and species, two related concepts

Taxonomic categories

The species is the basic taxonomic category used by biologists to classify living things. The other categories (genus, family, order, class and phylum) are considered artificial and arbitrary. On the other hand, we tend to regard the species as natural, obvious, similar to a concept when the represented objects are living beings. But we will not enter here into the famous problem of universals, nor wonder on whether concepts (and species) really exist or are mere constructs of the human mind.

The classic definition of a species is: a set of living beings that share common characteristics and can interbreed, giving rise to fertile offspring. Notice that the use of the word interbreed implies that the living things in question use sexual reproduction. This leads us to ask whether the concept of a species should be restricted to living beings with this type of reproduction, or it can be extended to those that reproduce otherwise, such as prokaryotes and some eukaryotes. This question can be answered in several ways:

The origin of sexual reproduction

Cromosomas X e Y

Sexual reproduction is the most common form of reproduction among eukaryotes, including multi-cellular living beings. After billions of years of asexual reproduction among prokaryotes, who share genetic information by exchanging plasmids (small DNA fragments), a new type of reproduction suddenly appeared. As it was successful, we must assume that it must have provided some advantage over the alternative procedure.

Sexual reproduction can be defined as the alternation between two life cycles for the same type of organism:

• Haploid cycle: each cell has a single copy of every chromosome.
• Diploid cycle: each cell has two copies of every chromosome.

In eukaryotes, the haploid cycle is always unicellular; the diploid cycle may be unicellular (in unicellular eukaryotes) or multi-cellular (in multi-cellular eukaryotes). The individuals in the haploid cycle are called gametes.

How was this alternation established? It could have been caused by an alternation between two different environments. Haploid and diploid cells do not have the same properties. For example, diploid cells are more voluminous, having many duplicate organelles, so that the ratio of surface to volume is usually larger than in haploid cells (about 1.25 times). As the absorption of nutrients by the cells depends on their surface, haploids tend to grow faster than diploids.

Outstanding problems in the history of life

Gregor Mendel

In a previous article I wrote about the origin of life and related problems. That is only the first of the outstanding issues regarding evolution. There are many more, for we are far from having an explanation for everything that happened during the history of life.

The theory of evolution through natural selection was first proposed by Darwin and refined by his followers when new discovered biological phenomena solved some of the problems posed since the beginning of the theory:

1.      The laws of heredity (Mendel, 1865).

2.      Mutations (Hugo de Vries, 1900).

3.      The laws of genetics (Thomas Hunt Morgan, early twentieth century).

4.      The synthetic theory of evolution (Simpson, Dobzhansky and others, around 1930)

5.      The transmission of inheritance through DNA (Oswald Avery, 1944).

6.      The structure of DNA and the deciphering of the genetic code (Watson, Crick, Rosalind Franklin and others).

7.      The neutral theory of evolution (Motoo Kimura, 1968).

8.      Punctuated equilibrium (Stephen Jay Gould, 1972).

9.      Epigenetics (early twenty first century).

Rosalind Franklin

The slaughter of the innocents

This image shows a possible result of the tests
described in the post. Black figures represent
pregnant women who tested negative.
Red figures are false positives.
Only the white figures are true positives.
Above-left are the results
for the Down syndrome

A study performed a few years ago [1] describes a delicate situation regarding certain widely used medical tests. The triple test has been performed on many pregnant women in order to detect whether the fetus will have the Down syndrome and other deficiencies. When the test is positive, gynecologists often recommend an amniocentesis or a chorionic villus sampling (biopsy), but as these tests involve some risk, many pregnant women do not want to do it, and some may decide to have an abortion based only on the results of the triple test.

The Down syndrome affects approximately 0.13% of fetuses. The problem is that the triple test used to detect it has a 70% sensitivity (or what is the same, the probability of a false negative is 30%) and a 91% specificity, which means that the probability of a false positive is 9%.

How should we interpret these numbers?

Suppose the triple test is performed on 1000 pregnant women. By applying the above data we conclude that:

•         The likely number of fetuses affected by Down syndrome will be 1 or 2.

•         The probability of detecting them with the test is 70%.

•         90 women (9% in 1000) will test positive, even if their child won’t be affected by the Down syndrome.

About the problem of evil

The Auschwitz concentration camp

In a previous article on the hunting hymenoptera I mentioned the problem of evil, often called the problem of pain, the well-known title of a book by CS Lewis. Although this question is mainly ethical or philosophical, it also has some relationship with science, as will be seen at the end of this post.

We can consider two different types of the problem of evil:

1. Human evil, caused by man. The Auschwitz concentration camp has become its most mentioned paradigm.
2. Natural pain, the fact that natural processes can cause severe pain to humans and other living beings.

Are we about to become immortal?

Arthur C. Clarke

In 1965 Arthur C. Clarke published a short story, titled Dial F for Frankenstein, later published in the collection The wind from the sun: stories of the space age. In that story Clarke proposed the following scenario:

When all global telephone systems are connected via geostationary satellites, the number of components of the global system will exceed those in the human brain. As such a system will have access to the information in all the computers connected to the network, we’ll have a very complex system with an extremely high amount of information. If conscience arises automatically from such a system, the computer network, connected by telephone, should be conscious and, being far superior to any human brain, will take control of the Earth.

What is life?

Saccharomyces cerevisiae

After a century discussing about the origin of life, we are not closer to knowing what did happen. In the mid-twentieth century, when Stanley Lloyd Miller performed the famous experiment where he applied energy to a mixture of methane, hydrogen, ammonia and water, and obtained amino acids, scientists announced the imminent manufacture of artificial life in the laboratory. Such estimates are often too optimistic. In this case they were.

The first question to be solved here is what is meant by being alive. If we consider the problem carefully, we’ll find beings that are clearly alive and others that definitely are not. Plants, animals and ourselves are alive. Stones, distilled water, carbon dioxide, are not. In these cases deciding is no trouble. When Antony van Leeuwenhoek discovered microorganisms (yeast, infusorians, bacteria, spermatozoa and red blood cells) nobody doubted that they are alive. But things are not always so simple.

The scientific work of Stephen Hawking

The scientific work of Stephen Hawking has been quite productive, although the media, influenced by his sad personal situation, tend to exaggerate its importance, putting him sometimes at the level of Einstein. His most renowned works are the following:

• The singularity theorems, published in 1970 in collaboration with Roger Penrose, proved that the application of the equations of Einstein’s General Relativity to the entire universe requires at least one singular point in that universe (a point where all the geodesics in the universe converge). As a consequence of this theorem, in the book The Large Scale Structure of Space-Time (1973, written with George Ellis), Hawking unequivocally embraced the theory that the universe began at a point of infinite density (the Big Bang).