Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

Can be answered at many levels.

1. When the transcription factor (TF) binds to the promoter

2. When the intra-cellular environment signals transcription via TFs

3. When the inter-cellular environment signals transcription, e.g. via testosterone

4. When the inter-organismal environment signals transcription, e.g. a mother smelling her newborn.

Overall, this is the concept of if-then clauses.

1. Example: if you smell your newborn baby, then express genes related to nursing.

What's 1 molecular mechanism and 1 example of epigenetic regulation?

1. 
   Chromatin packing patterns can be set for life.
   
2. 
   Examples include
   
   1. 
      Metabolic programming during the Dutch Hunger Winter
      
   2. 
      Stress reactivity in rats as a function of licking and grooming from the mother
      

What do transposons do and where do we see them play out in nature?

1. Transposons are mobile bits of DNA clipped by transposases and inserted into random parts of the genome

2. Originally found by Barbara McClintock in corn. Often found in plants as a stress response to come up with a novel solution under dire circumstances that plants can't run away from.

3. Also seen in neuronal wiring of mammalian brains. Significance: the organ having MOST to do with behavior is LEAST deterministically goverend by one set of genes. A lot of noise in the system and less of a role for a deterministic view of genes.

4. Also seen in parasites like the trypanosome worm which uses transposons to reshuffle its surface signal proteins to evade immune defenses.

5. Also seen in the immune system of mammals.

What's the basic idea of Punctuated Equilibrium (PE) and what's the evidence for it? How do gradualists respond to those claims?

1. 
   PE is a model that explains evolution. The idea is that there are long periods of stasis (the equilibrium part) in which nothing exciting really changes and then periods of saltation (the punctuated part).
   
2. 
   Paleontological evidence: we see in the fossil record what looks like saltatory change and periods of equilibrium
   
   1.