Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

Information flows from a unique DNA sequence (a gene) to an RNA sequence to an amino acid sequence.

By extension, one gene specifies one protein which has one shape and therefore one function

And what is the main challenge to the central dogma in this course?

1. 
   That one stretch of DNA can actually lead to many different proteins (through alternative splicing)
   
2. 
   (also retrotranscription in viruses from RNA --> DNA)
   
3. 
   (also one protein can take on multiple conformations and serve different functions)
   

What are the molecular bases for the three tenets of evolution by natural selection?

1. 
   Traits are heritable: you get your genes from your parents, and them from their parents, and so on.
   
2. 
   Variation: different alleles (versions of genes) code for slightly different proteins that serve the same function.
   
3. 
   Differential fitness: those different versions might do their protein job slightly better or worse, depending on the environment in which they're working
   

What are the three types of mutations in classical genetics?

1. 
   A point mutation when a single nucleotide is copied differently (incorrectly) between a mother cell and a daughter cell.
   
   1. 
      Can be a neutral mutation thanks to the redundancy of the codons. That is, multiple sets of 3 DNA bases will code for the same amino acid. So if the point mutation changes from one codon into a different but reduntant codon, it's a neutral/silent mutation.
      
2. 
   An insertion mutation leading to a frameshift.
   
3. 
   A deletion mutation leading to a frameshift. Deletions can also be of entire genes.
   

*What do we mean by microevolutionary vs. macroevolutionary change?

1. 
   Micro: a change in a single protein that affects a single protein and the downstream effects of having a differently shaped protein.
   
2. 
   Macro: a change in something (promoter, transcription factor, splicing enzyme, transposase, etc) that produces far-reaching changes in the way many proteins are made or when they are expressed.
   

Four examples of a microevolutionary change having a big impact on behavior?

1.