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Evolutionary speed limited by water in arid Australia
Xavier Goldie1, Len Gillman, Mike Crisp
1School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland 1020, New Zealand. xavier.goldie@anu.edu.au
Proceedings. Biological Sciences
|April 23, 2010
Summary
Water availability, not just temperature, influences evolutionary speed. Arid Australian plants evolve slower than those in moist habitats, supporting the evolutionary speed hypothesis for biodiversity patterns.
Area of Science:
- Ecology
- Evolutionary Biology
- Climate Science
Background:
- Biodiversity covaries with climate, but its ultimate cause is debated.
- The evolutionary speed hypothesis links ambient temperature, micro-evolutionary rates, and species richness.
- Previous studies show faster molecular evolution in warmer climates for various organisms.
Purpose of the Study:
- To investigate the independent influence of water availability on micro-evolutionary processes.
- To test the evolutionary speed hypothesis in relation to the water-energy balance in plants.
- To provide evidence for the role of water availability in shaping plant diversity patterns.
Main Methods:
- Utilized methodology to isolate micro-evolutionary processes from cladogenetic and demographic effects.
- Compared evolutionary rates of woody plants in arid Australian Outback habitats versus mesic continental margins at similar latitudes.
- Focused on woody plants to examine the impact of water availability.
Main Results:
- Woody plants in the arid Australian Outback exhibit slower micro-evolutionary rates compared to related species in moist habitats.
- This finding provides the first evidence for water availability as an independent factor influencing micro-evolutionary speed.
- Results suggest a modified evolutionary speed explanation for the water-energy balance and plant diversity relationship.
Conclusions:
- Water availability is a significant factor influencing micro-evolutionary rates, independent of temperature.
- The evolutionary speed hypothesis can be extended to incorporate the water-energy balance for understanding biodiversity patterns.
- Findings contribute to a more comprehensive understanding of climate-driven biodiversity gradients.
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