GULF OF GUINEA ISLANDS' BIODIVERSITY
NETWORK
ANALYSIS OF ASYMMETRIES IN THE
AFRICAN FRUIT BATS Eidolon helvum AND Rousettus
egyptiacus (MAMMALIA: MEGACHIROPTERA) FROM THE ISLANDS OF THE GULF OF
GUINEA. II. INTEGRATION AND LEVELS
OF MULTIVARIATE FLUCTUATING ASYMMETRY ACROSS A GEOGRAPHIC RANGE.
JAVIER JUSTE 1,2, CELIA LÓPEZ-GONZÁLEZ,3 AND
RICHARD E. STRAUSS3
1.
Estación Biológica de Doñana
(CSIC), Sevilla, 41080, Spain.
2.
Departamento de Bioquímica
y Biología Molecular IV. Facultad de Veterinaria,
Universidad Complutense de Madrid, Madrid, Spain.
3.
Department of Biological
Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA.
Abstract
Using a set of cranial morphometric characters, trends of variation in multivariate fluctuating asymmetry were evaluated and compared in populations of African fruit bats Rousettus egyptiacus and Eidolon helvum from the Gulf of Guinea islands, and the adjacent mainland. Levels of asymmetry were compared across populations and species, and significant differences were found in both comparisons. Differences coincided with species-specific patterns of morphological and genetic differentiation. Concordance of correlation matrices of asymmetry was also compared. Results were significant; concordance is hypothesized to be a by-product of developmental processes that produce the “fox-like” morphology shared by these species. Consistency of asymmetry patterns suggests that the developmental pathway producing it is highly canalized. A prediction of the above hypothesis is that a radical change in the “fox-like” structural pattern would result in breakage of the asymmetry parameter associated to it.
Key words: Fluctuating asymmetry, Geographic variation, Eidolon helvum, Rousettus egyptiacus, fruit bats, Gulf of Guinea.