Evolution of the Androgen-Induced Male Phenotype

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2018 Jan;204(1):81-92. doi: 10.1007/s00359-017-1215-3. Epub 2017 Oct 12.

Abstract

The masculine reproductive phenotype varies significantly across vertebrates. As a result, biologists have long recognized that many of the mechanisms that support these phenotypes-particularly the androgenic system-is evolutionarily labile, and thus susceptible to the effects of selection for different traits. However, exactly how androgenic signaling systems vary in a way which results in dramatically different functional outputs, remain largely unclear. We explore this topic here by outlining four key-but non-mutually exclusive-hypotheses that propose how the mechanisms of androgenic signaling might change over time to potentiate the emergence of phenotypical variation in masculine behavior and physiology. We anchor this framework in a review of our own studies of a tropical bird called the golden-collared manakin (Manacus vitellinus), which has evolved an exaggerated acrobatic courtship display that is heavily androgen-dependent. The result is an example of how the cellular basis of androgenic action can be modified to support a unique reproductive repertoire. We end this review by highlighting a broad pathway forward to further pursue the intricate ways by which the mechanisms of hormone action evolve to support processes of adaptation and animal design.

Keywords: Birds; Endocrine system; Neuromuscular; Skeletal muscle; Social behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Androgens / metabolism*
  • Animals
  • Behavior, Animal / physiology*
  • Evolution, Molecular*
  • Humans
  • Male
  • Passeriformes / genetics
  • Passeriformes / metabolism
  • Phenotype
  • Sex Characteristics*

Substances

  • Androgens