Oaks: an evolutionary success story

Area of Science:

• Evolutionary Biology
• Botany
• Ecology

Background:

• The genus Quercus (oaks) is a widespread and species-rich genus in the Northern Hemisphere.
• Extraordinary species diversity in America and Asia, and continuous distribution in Europe, prompt questions about oak evolutionary success.

Purpose of the Study:

• To illuminate the macro- and microevolutionary processes driving the radiation and expansion of oaks.
• To synthesize findings from phylogenetics, phylogeography, genomics, ecology, paleobotany, population biology, and quantitative genetics over the past three decades.

Main Methods:

• Review and synthesis of existing research from complementary scientific approaches.
• Analysis across scales of time and geography to identify overarching evolutionary explanations.

Main Results:

• Four key factors contribute to oak evolutionary success: 1. Accumulated diversity within populations and species. 2. Rapid migration enabling ecological priority effects. 3. High divergence rates within clades and convergent ecological solutions. 4. Hybridization promoting adaptive introgression and migration.

Conclusions:

• The evolutionary success of oaks is attributed to a combination of intrinsic diversity, dispersal capabilities, adaptive radiation, and genetic exchange.
• Future research should integrate microevolutionary and macroevolutionary perspectives to further understand oak evolution.