The molecular analysis confirms that all Laparocerus weevils have a common evolutionary ancestor (monophyly), but could not clarify whether that ancient founding species arrived from southern Europe or northwestern Africa. The two extant Moroccan species were found to be the result of a back-colonisation from the Canary Islands to Africa, and not the ancestral source lineage, which unfortunately is still unknown.
The evolutionary process responsible for such richness comprises sequential radiation events in these archipelagoes, each generating several monophyletic groups. These groups, 20 in total, have been recognised as subgenera of Laparocerus, and five of them — Aridotrox, Belicarius, Bencomius, Canariotrox, and Purpuranius — are described as new to science in this study. Colonisation routes, habitat shifts, disruption of populations by volcanism, dispersal by massive landslides, and other relevant aspects for adaptive and non-adaptive radiation, are largely discussed and confronted with previously published data referring to other groups of beetles or to other biological organisms (spiders, bush crickets, plants, etc.).
“If oceanic islands have been traditionally considered as laboratories of evolution and species-producing machines, Laparocerus will become the ideal guinea-pig for broadening studies in dispersal and speciation processes of all kinds,” say the authors. “Working with such a group is like getting a picture of Nature with more pixels. Several intriguing cases highlighted in this contribution may turn into the inspiration for further phylogeographic research.”
The scientists hope that, in near future Laparocerus will merit sharing the podium with Darwin´s finches or Drosophila in the studies of island evolution.” – Antonio Machado, Eduardo Rodríguez-Expósito, Mercedes López, Mariano Hernández. Phylogenetic analysis of the genus Laparocerus, with comments on colonisation and diversification in Macaronesia (Coleoptera, Curculionidae, Entiminae). Paper. (public access) ZooKeys, 2017; 651: 1 DOI: 10.3897/zookeys.651.10097 More.
But how many of the “120 recently discovered weevils placed in the genus Laparocerus,” making a total of “237 known species and subspecies,” should be classified that way, apart from claims to have catalogued or observed the development of a new species? The whole area of species classification should be considered a scandal, but for obvious reasons, it won’t be.
And Darwin’s finches? Well, let’s hope not if the authors want to demonstrate the development of new species. The changes turned out to be due to hybridization and environment factors but we don’t hear much publicity about that.
Note: The authors use the term “evolutive.” Seemingly rare usage.
See also: Nothing says “Darwin snob” like indifference to the mess that the entire concept of speciation is in.
Darwin’s finches not a good example of Darwinian evolution?
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