Evolution (Evolution)

by dhw, Sunday, February 08, 2009, 10:22 (5765 days ago) @ David Turell

David referred us to an article entitled "Key Insights into How New Species Emerge", which ... briefly ... describes how, with the introduction of the apple into North America, some fruit flies which had mated and laid eggs on hawthorns switched to apples instead. This apparently gave rise to changes both in the flies and in the wasps that fed on the larvae. The article goes on to claim that the research "gives insights into solving Darwin's mystery of the origins of new species", and repeats several times over that these were indeed new species. - I find this both intriguing and puzzling, and would greatly appreciate some explanations. - Firstly, the apple fruit flies and wasps are still fruit flies and wasps, so when do variations qualify to be called new species? - Secondly, at what stage do these variations appear? Do the adults undergo a metamorphosis which they pass on to the larvae, or do the larvae differ from the adults? If it's the adults that change, was Lamarck right about the inheritance of acquired characteristics?