Differences in spawning date between populations of common frog reveal local adaptation

Area of Science:

• Ecology
• Evolutionary Biology
• Climate Change Biology

Background:

• Phenotypic variation between populations often links to climate, driven by plasticity and local adaptation.
• Species with genetic local adaptation to climate are more vulnerable to climate change than plastic ones.

Purpose of the Study:

• To compare spatial and temporal covariation of temperature and common frog spawning dates.
• To assess the role of local adaptation versus plasticity in common frog spawning timing.
• To project the impact of climate change on common frog spawning dates.

Main Methods:

• Utilized a large dataset (>50,000 observations) of common frog (Rana temporaria) spawning dates across Britain.
• Compared temperature-spawning date covariation across different locations (space) and across years (time).

Main Results:

• All common frog populations demonstrated temperature-induced plasticity, with earlier spawning in warmer years.
• Differences in spawning dates between populations were primarily driven by local adaptation, not just plasticity.
• Projected climate change (2050-2070) suggests spawning dates need to advance 21-39 days for continued local adaptation.

Conclusions:

• Plasticity alone is insufficient to meet future spawning date advancements needed for local adaptation.
• Common frog populations face a significant microevolutionary and gene flow challenge to adapt to projected climate change.
• Local adaptation plays a dominant role in common frog spawning phenology, but its pace may be outstripped by climate change.