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Hormonal organization and activation: evolutionary implications and questions
1Department of Psychology, Cornell University, Ithaca, New York, USA. er12@cornell.edu
General and Comparative Endocrinology
|January 18, 2012
Summary
Comparative endocrinology explores how genes and hormones shape sexual differences in vertebrates. Understanding the evolutionary diversity in these processes, like body size and behavior, is key to future research.
Area of Science:
- Comparative endocrinology
- Evolutionary developmental biology
Background:
- Sexual dimorphism and differentiation involve genes and sex steroid hormones.
- Vertebrate research has revealed conserved principles alongside striking diversity in sexual differentiation.
- The evolutionary basis and adaptive functions of this diversity are not well understood.
Purpose of the Study:
- To explore the integration of ultimate and proximate causation in comparative endocrinology.
- To highlight the potential of studying sexual dimorphism and differentiation for this integration.
- To raise questions regarding the evolutionary basis of diversity in sexual differentiation mechanisms.
Main Methods:
- Examining mechanisms of sexual dimorphism in body size and ornamentation.
- Investigating sexual differentiation of avian behavior (e.g., Japanese quail, zebra finches).
- Analyzing the phylogenetic distribution of vertebrate sex-determining mechanisms.
Main Results:
- Established discoveries on the role of genes and sex steroids in sexually differentiated traits.
- Identified significant diversity in sexual differentiation processes across vertebrates.
- Highlighted gaps in understanding the evolutionary history and adaptive functions of this diversity.
Conclusions:
- A comparative approach, integrating phylogenies and evolutionary developmental biology (e.g., developmental modules), can generate testable hypotheses.
- This approach holds promise for answering fundamental questions about sexual differentiation diversity.
- Further research is needed to fully understand the evolutionary underpinnings of sexual dimorphism.
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