Sunday, March 1, 2015

Interview with Manuel Alfonseca

This is the translation of an interview about my activity as an author of fiction, published in El Templo de las Mil Puertas


1.         What drives an apparently scientific person to get involved on the wonderful task of creating, writing and sharing stories?
Many scientists have written novels, especially in the genre of science fiction. To name a few: Carl Sagan, Leo Szilard, George Gamow and Willy Ley. I also like to try other genres. Throughout my life, I've been interested in many subjects that are not supposed to be science, such as history or philosophy. Later, when I tried to express myself in the field of fiction, such knowledge found its natural place.

Thursday, February 26, 2015

Natural selection is more complicated than we thought

Jacques Monod
In his famous popular book Le hasard et la nécessité (1970), Jacques Monod said that evolution is the result of the interaction of two types of phenomena: chance (mutations, environmental changes) and necessity (natural selection) .
More precisely, natural selection can be considered as the action of a random element (the environment) over another random element (the genetic make-up of living beings). According to the synthetic theory of evolution, who is now over 80 years old, that action is quasi-deterministic (Monod’s nécessité).
A further development of the synthetic theory of evolution is Richard Dawkins’s selfish gene theory, which asserts that adult living beings are just the means that allow genes to perpetuate. Although it had some significant detractors (Stephen Jay Gould, for instance), this theory was accepted by many biologists in the two decades after its statement.
However, in recent years, advances in genomics and evolutionary biology are beginning to question the accuracy of the synthetic theory of evolution and the selfish gene. Make no mistake: this does not mean that the theory of evolution is in question, what is being discovered is the fact that things are not as simple as they seemed. The following is a sample of some of the problems detected, culled from the book The year in evolutionary biology, Annals of the New York Academy of Sciences (2008).
·         Epigenesis: genes are more interconnected than thought. A mutation in a gene can make another gene work in a completely different manner, complicating the action of natural selection.
·         Quasi-neutrality: slightly deleterious mutations seem to be immune to natural selection and are perpetuated over generations.
·       
The tree of life
 
The development and hybridization of viviparous beings (which include such different organisms as mammals and flowering plants, among others) are not as simple as implied by the Dobzhansky-Muller principle, associated with the synthetic theory of evolution. Hitherto unsuspected effects take a part, such as genomic imprinting (substantial differences in the expression of maternal and paternal genes during development).
·         The fundamental dogma of the synthetic theory (the genotype uniquely determines the phenotype) is now questionable. Not only it is true (what was already known) that the genotype is plastic, and depending on the environment can lead to several different phenotypes (to see this, just compare the different types of cells of the same organism, which are very different, although they share the same genome). What is unexpected is the finding that several different genotypes may result in the same phenotype; a setback for Dawkins’s selfish gene theory. The relationship between genotype (genes) and phenotype (the physical aspect of the living adults) happens to be many-to-many in both directions, and the development of the phenotype from the genotype is more deeply influenced by the environment than previously thought.

The same post in Spanish
Thematic thread on Evolution: Preceding Next
Manuel Alfonseca

Thursday, February 19, 2015

Science is a tool

Francis Bacon
The utopia The New Atlantis, written by Francis Bacon, a contemporary of Galileo and pioneer of modern philosophy of science, describes a perfect society that would automatically arise from the practice of science, which the inhabitants of the island of Bensalem have made the basis of their society and its government. Like many of his encyclopedic followers, who a century later created the myth of indefinite progress, Bacon believed that science in the future will save man and solve all human problems, opening the way to a paradise on Earth.
This mistake is common. Tools are often confused with their good uses, forgetting that the same tools can also be misused. Let’s look at a few examples, among the thousands that could be cited:

Thursday, February 12, 2015

A photograph from the abyss of time

The cosmic background radiation as detected by the Planck satellite telescope
When the space telescopes sent by NASA and the European Space Agency (COBE, WMAP, Planck) send us data on the cosmic background radiation, the corresponding images usually appear on the first page of high-diffusion newspapers, accompanied by headlines that are not always correct. Let's look at a few, published in Spanish newspapers:

Thursday, February 5, 2015

The monkey pounding on a typewriter

In connection with the fine tuning problem, the argument of the typist monkey is often used as an illustration that even very unlikely events can occur spontaneously. Depending on the author of the quote, the text supposedly written by the monkey can be the complete works of Shakespeare, Don Quixote, or even a shorter and less specific work. For instance, John Leslie, in his book Universes (Chapter One), writes:
Our universe can indeed look as if designed. In reality, though,  it may be merely the sort of thing to be expected sooner or later. Given sufficient many years with a typewriter, even a monkey would produce a sonnet.

Thursday, January 29, 2015

The mystery of the Cambrian explosion

Opabinia
550 million years ago, during the Cambrian period, animals appear suddenly in the fossil record. This spectacular phenomenon has been given the name of Cambrian explosion. Why did it happen then, and not before, has been, for over a century, one of the great mysteries of paleontology.
The evolution of life on Earth seems to have been rather discontinuous. Life is likely to have appeared 3,500 to 4,000 million years ago. Not much later, around 3,000 million years ago, photosynthesis appeared. Eukaryotes (cells with nuclei) emerged 2,000 million years ago. From then until the Cambrian explosion, nothing much seems to have happened for 1,500 million years. Then all the types of organization of the animals existing today appear suddenly. Why?

Thursday, January 22, 2015

The case of the hunting hymenoptera

Jean-Henri Fabre
In 1879, the French entomologist J. H. Fabre studied many species of hymenoptera (solitary wasps and bees) that hunt other insects as food for their larvae. This is the reason for their name (hunting hymenoptera, also called -improperly- parasite hymenoptera). Before laying the eggs, the hymenoptera paralyze the prey by injecting with their sting a drop of poison in every nerve ganglion in the un-centralized nervous system of the prey. In some species, such as Ammophila hirsuta, which hunts caterpillars, the number of ganglions may be large (up to twelve, one per segment in the caterpillar). The hunter seems to know where exactly its prey must be stabbed with the sting.
Once the prey has been paralyzed and the egg laid, the minute larva of the hymenopter digs inside the prey and starts devouring it, showing an apparent innate knowledge of the prey anatomy: it starts feeding on the parts less necessary for life, leaving the vital organs to the last. In this way, the prey does not die and rot, which would make it improper as food and lead to the death of the predator.
Ammophila sabulosa carrying a hunted caterpillar