Fluctuating and directional asymmetry in natural bird populations exposed to different levels of habitat disturbance, as revealed by mixture analysis

Citation
L. Lens et S. Van Dongen, Fluctuating and directional asymmetry in natural bird populations exposed to different levels of habitat disturbance, as revealed by mixture analysis, ECOL LETT, 3(6), 2000, pp. 516-522
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
3
Issue
6
Year of publication
2000
Pages
516 - 522
Database
ISI
SICI code
1461-023X(200011)3:6<516:FADAIN>2.0.ZU;2-L
Abstract
While bilateral trait asymmetry is widely recognized to estimate developmen tal instability, much controversy exists over which types of asymmetry (flu ctuating, directional, and/or antisymmetry) to use. Recently it has been hy pothesized that the three types are strongly interrelated, and that increas ed developmental instability may be reflected in a transition from fluctuat ing to directional asymmetry and/or antisymmetry. Alternatively, habitat di sturbance might change the genetic expression of directional asymmetry. We present herein the first empirical evidence for stress-mediated shifts in t ypes of asymmetry in natural populations, by using mixture analysis to mode l tarsus asymmetry in bird populations exposed to different levels of habit at disturbance. Observed asymmetry patterns almost exclusively consisted of true fluctuating asymmetry in the least disturbed populations, but became progressively mixed with directional asymmetry under increasing disturbance . Failing to unravel these mixtures of different forms of asymmetry may hav e critical implications for the analysis and interpretation of asymmetry da ta.