Theory 40/Centuries/Biogeography
Ranges Track Climate Velocity
The claim
Whether a species keeps pace with climate is set by the ratio of dispersal rate to climate velocity, so a fast climate with slow dispersal leaves a lag that grows into extinction debt.
01Mechanism
The climate envelope moves at a velocity; the species must move at least as fast to stay within it.
02Prediction
Lag should track the ratio.
03Refutation
Lag tracking climate change alone would remove dispersal.