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).