Η εξέλιξη του λύκου σε σκύλο

AFP/Getty Images; Wikipedia
© AFP/Getty Images; Wikipedia

Μία πολύ ενδιαφέρουσα ανακάλυψη δημοσιεύτηκε στο περιοδικό PLoS ONE με τίτλο “A 33,000-Year-Old Incipient Dog from the Altai Mountains of Siberia: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum”. Η ανεύρεση ενός κρανίου προγόνου του σημερινού σκύλου σε σπηλιά στη Σιβηρία, φωτίζει με διαφορετικό τρόπο την καταγωγή του. Όπως ισχυρίζονται οι συγγραφείς -μια ομάδα από Ρωσία, Βρετανία, ΗΠΑ και Ολλανδία- η εξέλιξη του λύκου σε σκύλο δεν οφείλεται στην «τεχνητή» και συνειδητή επιλογή του ανθρώπου. Πρόκειται μάλλον για εξελικτική διαδικασία που έλαβε χώρα σε διαφορετικά σημεία του πλανήτη και αρκετές φορές.

Αποσπάσματα από τη δημοσίευση:

Morphological, behavioral and genetic evidence all suggest that dogs evolved from ancient wolves, probably several times. Traditional anthropological definitions of domestication consider the process to be a deliberate act of selection by humans. However, this view has been challenged in recent years by the hypothesis that animals colonized anthropogenic environments of their own volition and evolved into new (“domestic”) species via natural evolutionary processes because it better fits a number of associated observations, including the evidence from genetics that domestication took place multiple times over geographic space and chronological time in virtually all mammalian taxa. After initial changes occurred, the resulting new species were modified during their association with people via natural adaptation, human selection, and genetic drift.

Since dog domestication almost certainly occurred multiple times without direct human selection, we suggest that it must have occasionally failed. That is, the particular set of ecological conditions associated with human settlement and hunting practices that were necessary to initiate the domestication process must have, on some occasions, existed only long enough to produce a few modified wolves (i.e. incipient dogs) with short-lived lineages.

Wolves appear to have been especially attracted to permanent or semi-permanent human settlements. Persistent dog lineages arose in Europe, the Middle East, and China by the end of LGM – early Holocene. By ca. 14,000 cal BP, dogs had become a consistent component of human settlements and were subject to deliberate burial themselves and were included in human graves.

Remains of both incipient dogs and early true dogs are critical indicators that a particular set of natural ecological conditions and human-mediated social factors existed at certain times in the past. Mapping the geographic extent and chronological order of these events enriches our understanding of human history and evolutionary processes. The fact that the Razboinichya canid is likely an early incipient dog rather than the oldest ancestor of modern dogs in no way detracts from its historical or biological importance.