Do differences in developmental mode shape the potential for local adaptation?

Area of Science:

• Marine biology
• Ecology
• Climate change adaptation

Background:

• Climate change is causing species redistribution due to rising temperatures.
• Local adaptation can help species persist, but dispersal and gene flow may limit it.
• Understanding thermal adaptation is crucial for predicting species' responses to climate change.

Purpose of the Study:

• To investigate the prevalence of local adaptation to temperature in two congeneric marine gastropod species with different developmental modes.
• To explore how thermal physiology varies across a latitudinal thermal gradient.
• To compare the adaptive capacity of a highly dispersive species versus a sedentary species.

Main Methods:

• Collected Littorina littorea and L. saxatilis from a latitudinal thermal gradient.
• Quantified acute metabolic rate response (oxygen consumption) to temperature changes (6°C–36°C).
• Analyzed thermal optimum (Topt), thermal breadth (Tbr), and maximal performance (Vmax) across populations.

Main Results:

• Littorina littorea showed minimal local adaptation, with no change in Topt or Tbr and declining Vmax with latitude.
• L. saxatilis exhibited evidence of local optimization, but with idiosyncratic variation across latitudes.
• Biogeography of thermal traits differed significantly between the two related species.

Conclusions:

• Dispersal ability influences the capacity for local thermal adaptation in marine gastropods.
• Interpopulation differences in thermal performance are complex and do not always correlate with latitudinal temperature changes.
• Further research is needed to understand mechanisms of local adaptation and predict species redistribution under climate change.