Hybrid zones are, roughly speaking, narrow regions in which genetically distinct populations
meet, mate, and produce hybrids. They are often only a few hundred meters wide and yet …

▪ Abstract Mimicry and warning color are highly paradoxical adaptations. Color patterns in
both Müllerian and Batesian mimicry are often determined by relatively few pattern …

No one in this century can speak with greater authority on the progress of ideas in biology
than Ernst Mayr. And no book has ever established the life sciences so firmly in the …

Avoiding Attack discusses the diversity of mechanisms by which prey avoid predator attacks
and explores how such defensive mechanisms have evolved through natural selection. It …

The phenomenon of Industrial Melanism has occurred as an indirect effect of a recent
environmental change: the pollution of the air from the combustion of coal, coke, and oil …

The selective forces imposed by agricultural practices have resulted in the evolution of
agricultural races of weeds or agroecotypes. Some agroecotypes are intimately associated …

Biological studies of mimetic Neotropical butterflies in the nymphalid tribe Helieoniini have
twice come full cycle in the past 100 years. Bates's classic writings (6, 7), reflecting …

Modern patterns of passifloraceous host plant choice by heliconiine butterflies suggest
parallel evolution in the two groups with appreciable mutual influence. There are strong …

We evaluate Sewall Wright's three‐phase “shifting balance” theory of evolution, examining
both the theoretical issues and the relevant data from nature and the laboratory. We …

A method is presented for quantitative estimation of the degree of crypsis of species seen by
visual predators against known backgrounds. It is based upon a comparison between …