Week 5

Sept. 27th


Finish Behavioral Genetics

As a simple introduction to the type of behaivoral genetic studies that have been done in Drosophila...
Vosshall L. 2007 The mind of a fly Nature 450:193-197.

Additional (more complicated studies concernning behavioral genetics)
Sokolowski (2001) Drosophila: Behavior meets Genetics. Nature Genetics 2:877-892.
MacKay, T.F.C. and Anholt, R.R.H (2008) Ain't misbehavin'? Genotype-environment interactions and the genetics of behavior. Trends in Genetics 23:311-314.
As a Neuroethology conference in Salamaca Spain during the summer of 2010 I heard a talk by Neil J. Vickers regarding his work to identify the genetic basis of species-specific olfactory behavior in two closely related moth species that was also recently published (Gould et al 2010). In my mind this is one excellent example of a study that bridges the gap. There is a recent short review of that work which may help to emphasize the important points (Heckel 2010).


Sept 29

Sexual election and Mate Choice

The past two decades have seen extensive growth of sexual selection research. Theoretical and empirical work has clarified many components of sexual selection, such as aggressive competition and mate choice. Perhaps even more importantly, recent work has begun to tease apart the relative contributions of pre- and postcopulatory mechanisms of sexual selection. While most students are familiar with pre-copulatory mechanisms, the post-copulatory mechanisms of sperm competition and selective sprem utilization play an important role in sexual conflict. Genetic mechanisms of mate choice evolution have been less amenable to empirical testing, but molecular genetic analyses can now be used for incisive experimentation. The texts we read and the discussion in class willhighlight some of the currently debated areas in pre- and postcopulatory sexual selection.

READ (requried)
Dugatkin chapter 6 and 7 (chapter 7 applies more to next week)

Andersson M. & Simmons, L.W. (2006) Sexual selection and mate choice. Trends in Ecology and Evolution 21:296-302.
Clutton-Brock T. (2008) Sexual Selection in Males and Females. Science 318:1182-1185.sexual selectionMalte Andersson

sexual selection

For a more modern look at research on mate choice see the following review.

Chenworth & Blows (2006) Dissecting the complex genetic basis of mate choice. Nat. Rev Genet. 7:682-692.
For a general review on sex determination and some interesting lesser known tidbits see:
Crews D. (1994) Animal Sexuality. Scientific American v?:107-114.

Classic Background: (If you are not familiar with the following, you should read the appropraite chapters in your introductory Biology textbook)
Entire courses are taught on Sexual Selection so it would be impossible to cover the topic thoroughly in one day. We will pay special attention to this theory as it would apply to behavior. Undoubtedly, sexual selection affects everything from morphology to the evolution of sex chromosomes, and even sex determination systems.

Charles Darwin distinguished sexual selection as variance in the number of mates.

"Sexual selection depends on the success of certain individuals
over others of the same sex, in relation to the propagation of the
species; while natural selection depends on the success of both
sexes, at all ages, in relation to the general conditions of life. "
—Charles Darwin, 1871

Sexual selection takes two major forms:
intrasexual selection (most commonly seen as 'male–male competition') in which members of the less limited sex (typically males) compete aggressively for access to the limiting sex (typically females),
intersexual selection (also known as 'mate choice', most commonly 'female choice') in which males compete with each other to be most attractive to females. As we will see later in the semester, these roles are reversed for some species. For today, we will consider cases in which Sexual Selection and Natural Selection may act in opposing directions.

Oct. 1st

Sex-role behavior

Sex-role reversal occurs when females compete more intensely than males for access to mates. In this lecture, we will survey the occurrence of sex-role reversal in vertebrates focusing on behavioural aspects of sex-role reversal and we will examine possible endocrinological and molecular correlates of this phenomenon using examples primairly form fish and birds. This area of research is a main focus of the Renn lab. Therefore, much of the work of previous Reed students Molly Schumer and Kelsey Wood will also be covered.

READ (required)
Eens, M. and Pinxten, R. (2001) Sex-role reversal in vertebrates: behavioural and endocrinological accounts. Behavioural Processes 51:135 – 147.