title: A steep cline in ladybird melanism has decayed over 25 years: a genetic response to climate change?
abstract: A cline in the frequency of melanic morphs of the two-spot ladybird, Adalia bipunctata, was first surveyed in 1980 along a transect extending inland from the coast in the Netherlands. At that time, the frequency of melanics increased over some 40 km from 10% near the coast to nearly 60% inland. Additional surveys made in 1991 and 1995 demonstrated some progressive change in cline shape. New samples from 1998 and 2004 confirm these dynamics, and show that over a period of about 50 generations for the beetle, the cline had decayed rapidly to yield rather uniform frequencies of melanic morphs at around 20% along the whole transect by 2004. Climate data and evidence for thermal melanism in this species support our contention that these dynamics reflect a dramatic example of a rapid genetic response within populations to climate change and local selection.
authors.affiliation: Institute of Biology, Leiden University, Leiden, The Netherlands. pb499@cam.ac.uk
authors.forename: P M
authors.initials: PM
authors.lastname: Brakefield
authors.forename: P W
authors.initials: PW
authors.lastname: de Jong
mesh_terms: D000818:Animals; D057231:Climate Change; D001517:Coleoptera / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008543:Melanins / Q000378:metabolism*; D009426:Netherlands; D010858:Pigmentation; D011157:Population Dynamics; D012641:Selection, Genetic
chemical_list: D008543:Melanins