 McShea and Brandon also argue that the ZFEL has the virtue of giving a unified account of both micro- and macro-evolutionary phenomena. They invoke the ZFEL to explain a wide variety of different patterns, ranging from complexity increase in the history of animal life, as represented by the fossil record, to increasing genomic heterogeneity over time. Whatever one thinks about their claim that the ZFEL is “biology’s first law”, their project raises a question worth exploring: is it reasonable to think that explanations of macroevolutionary patterns should take fundamentally the same form as explanations of patterns at vastly different spatiotemporal scales? How much does scale matter?