Modern Evolutionary Biology: Some Concepts, Questions and Comments in Relation to Birds

Abstract

There are four principles in evolution: variation, inheritance, selection and time. These principles summarizes natural selection. In the same way, sexual selection can be defined as the evolution of certain conspicuous physical traits, such as pronounced coloration, increased size, or striking adornments that may grant the possessors of these traits greater success in obtaining mates. Both concepts join on time in the branch termed evolutionary biology (EB). Current EB since Darwin had a primer at the end of the past century in the Trivers-Wilard’s hypothesis based on the relationships of parents’ effort with the condition of offspring. This hypothesis has required new brands termed “Sex-allocation“, “Parental Investment”, “Delayed Maturation” and “Sexy-sons” to conform the framework of the current EB. Here, I try to summarize the key concepts of these theories trying to bring the theme towards birds.