Adaptation of metabolism and evaporative water loss along an aridity gradient

Broad-scale comparisons of birds indicate the possibility of adaptive modification of basal metabolic rate (BMR) and total evaporative water loss (TEWL) in species from desert environments, but these might be confounded by phylogeny or phenotypic plasticity. This study relates variation in avian BMR...

Full description

Saved in:

Bibliographic Details
Published in:	Proceedings of the Royal Society. B, Biological sciences Biological sciences, 2003-01, Vol.270 (1511), p.207-214
Main Authors:	Tieleman, B. Irene, Williams, Joseph B., Bloomer, Paulette
Format:	Article
Language:	eng
Subjects:	Adaptation, Physiological Alaudidae Animals Aridity Basal Metabolic Rate Basal metabolism Basal Metabolism - physiology Biological taxonomies Birds Cytochrome b Group - genetics Desert Climate Deserts Ecological genetics Energy Metabolism Evolutionary genetics Genes, rRNA Larks Metabolism Molecular Sequence Data Phylogenetics Phylogeny RNA, Ribosomal, 16S - genetics Sequence Analysis, DNA Songbirds - genetics Songbirds - physiology Temperature Total Evaporative Water Loss Water loss Water Loss, Insensible - physiology
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Broad-scale comparisons of birds indicate the possibility of adaptive modification of basal metabolic rate (BMR) and total evaporative water loss (TEWL) in species from desert environments, but these might be confounded by phylogeny or phenotypic plasticity. This study relates variation in avian BMR and TEWL to a continuously varying measure of environment, aridity. We test the hypotheses that BMR and TEWL are reduced along an aridity gradient within the lark family (Alaudidae), and investigate the role of phylogenetic inertia. For 12 species of lark, BMR and TEWL decreased along a gradient of increasing aridity, a finding consistent with our proposals. We constructed a phylogeny for 22 species of lark based on sequences of two mitochondrial genes, and investigated whether phylogenetic affinity played a part in the correlation of phenotype and environment. A test for serial independence of the data for mass-corrected TEWL and aridity showed no influence of phylogeny on our findings. However, we did discover a significant phylogenetic effect in mass-corrected data for BMR, a result attributable to common phylogenetic history or to common ecological factors. A test of the relationship between BMR and aridity using phylogenetic independent constrasts was consistent with our previous analysis: BMR decreased with increasing aridity.
ISSN:	0962-8452 1471-2954