Session 1: Introduction

1.  Why Study the Primates?

• We are primates
• Primate-wide trends and phylogenetic patterns help us understand our own evolution
  
• Evolutionary patterns and species uniqueness--the comparative approach
• Conservation and human impact

2.  Important Terms & Definitions:

Phylogenetic

Evolutionary history

Functional

Impact on lifetime reproductive success or fitness

Mating patterns:

• Polygyny- one male mates with multiple females
• Polyandry- one female mates with multiple males
• Monogamy- one male and one female mate exclusively for one or more mating periods
• Polygamy or polygynandry - both males and females have multiple mating partners

Grouping patterns:

• multifemale/multimale
• one male/multifemale
• one female/multimale
• one female/one male
  
• solitary
• Higher level associations:
  • the community concept
  • one male unit (OMU), band, herd concept
  • community of groups concept
• Grouping patterns do not equal mating patterns

Age/Sex classes:

• Adult: socially and physically mature female and male
• Subadult: >75% adult size, physically capable of reproduction, not fully socially mature
  
• Juvenile/Immature: older than infant, and younger than subadult
  
• Infant: young and still dependent on mother for nutrition and majority of locomotion
  

Dominance and linearity

• Matrilineal/matrifocal:  female-centered kin structure
• Hierarchical:  clear linear dominance relationships
• Egalitarian:  non-linear dominance relationships, non-transitive dominance relationships

3. Evolutionary Fact and Theory:

Evolution is change over time. Evolutionary theory deals with understanding the mechanisms of evolution.  The population genetic definition of evolution is change in allele frequency over time.  This is important because the genetic composition of an organism, population, and species is related to behavior.  However, this relationship is generally not linear for complex organisms. Behavioral changes can be based on genetic changes.

Theodosius Dobzhansky (1900-1975):  "Nothing in biology makes sense, except in the light of evolution."

Three levels of the evolutionary process:

1. the origin of genetic novelties
2. the ordering of those novelties in “molding the genetic structure of populations into new shapes”
3. the “fixation of diversity already attained at the preceding two levels”

Four processes of evolution:

• Natural Selection
• Genetic Drift
• Gene Flow
• Mutation

Mutation:

• Changes to the nucleotide base sequence in the DNA  (genetic variation)
• Changes at the level of the locus/gene/allele…therefore changes in protein products and regulatory functions

Genetic Drift:

• occurs when a random event alters the genetic frequencies in a population such that subsequent generations have frequencies different from their parental generations

Gene Flow:

• the movement of genetic material within and between populations. Gene flow can be broken up into two principal components:

• • Migration and dispersal events

  • Non-random, or assortative, mating

Natural Selection:

• There is genetic variation in a population, and phenotypic variation is tied to that genetic variation.
• The traits (phenotypic variants) that do best in a given environment are heritable (have a genetic basis).
• Over time, the traits that contribute to organisms leaving, on average, more offspring per generation will become increasingly represented in the population as a result of this differential reproductive success.
• Genotype (genetic makeup) and Phenotype (expression of genotype)
• Heritability: the ability of a trait, either morphological or behavioral, to be passed as genetic information across generations
  
• Environmental challenges: the selective force or environment
  
• Reproductive success/Fitness: The survival of your offspring, and thus your genetic material, into the next generation
  

4.  Required Reading:

2007.  C.J. Campbell, A. Fuentes, K.C. MacKinnon, M. Panger, S.K. Bearder.  Oxford University Press.