title: Discontinuous variability of brain composition among domestic chicken breeds.
abstract: In 80 domestic chickens from 8 breeds, the volumes of 12 brain parts were identified as dimensions in a cluster analysis. Based on Euclidean metrics and the Ward algorithm at least 2 groups were found that are congruent with the breeds 'White Crested Polish chicken' and 'Breda', although the breed identity was not a variable used in the cluster analysis. Domestication is interpreted as evolution which includes the possibility of speciation. It is hypothesized that White Crested Polish chickens and Bredas are becoming new species in terms of a biospecies concept.
authors.affiliation: C and O Vogt Institute of Brain Research, University of Düsseldorf, Düsseldorf, Germany. Gerd.Rehkämper@uni-duesseldorf.de
authors.forename: Gerd
authors.initials: G
authors.lastname: Rehkämper
authors.forename: Emriye
authors.initials: E
authors.lastname: Kart
authors.forename: Heiko D
authors.initials: HD
authors.lastname: Frahm
authors.forename: Christian W
authors.initials: CW
authors.lastname: Werner
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001699:Biometry; D001835:Body Weight / Q000235:genetics; D001921:Brain / Q000033:anatomy & histology*; D002645:Chickens / Q000033:anatomy & histology* / Q000235:genetics; D005260:Female; D014644:Genetic Variation / Q000235:genetics; D008297:Male; D009929:Organ Size / Q000235:genetics; D010375:Pedigree; D013045:Species Specificity