Related Experiment Video
Updated: Jan 22, 2026

Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds
Published on: November 6, 2015
A dynamic continental moisture gradient drove Amazonian bird diversification
Sofia Marques Silva1,2,3, A Townsend Peterson4, Lincoln Carneiro1,2,5
1Museu Paraense Emílio Goeldi, Coordenação de Zoologia, Caixa Postal 399, 66040-170 Belém, Pará, Brazil.
Abstract:
The Amazon is the primary source of Neotropical diversity and a nexus for discussions on processes that drive biotic diversification. Biogeographers have focused on the roles of rivers and Pleistocene climate change in explaining high rates of speciation. We combine phylogeographic and niche-based paleodistributional projections for 23 upland terra firme forest bird lineages from across the Amazon to derive a new model of regional biological diversification. We found that climate-driven refugial dynamics interact with dynamic riverine barriers to produce a dominant pattern: Older lineages in the wetter western and northern parts of the Amazon gave rise to lineages in the drier southern and eastern parts. This climate/drainage basin evolution interaction links landscape dynamics with biotic diversification and explains the east-west diversity gradients across the Amazon.
Related Concept Videos
What is an Electrochemical Gradient?
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
Moisture Content and Bulking of Aggregate
When aggregates are exposed to rain or sit in stockpiles, they absorb moisture, which must be...
Energy Line and Hydraulic Gradient Line
Gradient and Del Operator
Dynamic Equilibrium
Electrochemical Gradient and Channel Proteins: An Overview
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to...

