Reproducere sexuata, selectie sexuala si variabilitate genetica / Sexual reproduction, sexual selection and diversity

In Jurnalul National din 30 martie apare un articol al Deliei Zahareanu intitulat “Campionatul genelor bune“. Autoare isi pune intrebarea care este corelatia dintre sexualitate si diversitatea genetica. Insa autoarea face confuzie intre sex, adica reproducerea sexuata, si selectia sexuala, care este cu totul altceva.

“Citita in cheia teoriei evolutiei, asa cum a fost elaborata de Darwin, reproducerea sexuala, vizand obtinerea celor mai bune gene de la mascul, duce la o fixare a unui bagaj genetic superior si la micsorarea plajelor posibile in care apar mutatiile care produc diversitatea speciei umane. Cu alte cuvinte, sexul, in teorie, limiteaza diversitatea si conserva cele mai bune caracteristici ale ADN-ului parintilor transferat in cel al copiilor.”

In timp ce selectia sexuala are intr-adevar ca rezultat micsorarea diversitatii genetice, reproducerea sexuata are in schimb ca efect marirea diversitatii genetice, prin recombinare genetica. Cele doua sunt fenomene antagonice. Selectia sexuala actioneaza asupra sursei de variabilitate genetica reprezentata de reproducerea sexuata.

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In Jurnalul National from 30 March there is an article from Delia Zahareanu, called “The Championship of the good genes”. The author writes about the correlation between sexual reproduction and genetic variability. But the author makes a confusion between sex (sexual reproduction) and sexual selection, which is a completely different thing.

“According to the Darwinian theory of evolution, sexual reproduction, aiming to obtain the best genes possible from the male, leads to the establishment of a superior gene stock and a smaller diversity for the human species. In other words, sex, in theory, limits the diversity and preserves the best characteristics of the parent DNA from parents to children.”

Meanwhile sexual selection results in a smaller genetic diversity, sexual reproduction results in a bigger diversity, because of genetic recombination. The two phenomenon are antagonistic. Sexual selection acts upon the source of genetic variability, which is sexual reproduction.