In the quest for understanding the structure of biological
  populations and communities, ecology and evolution are linked
  inevitably and intricately, with frequency- and
  density-dependent selection pressures playing key roles.
  Adaptive dynamics theory is a theoretical framework for analyzing
  the density- and frequency-dependent evolution of quantitative
  traits, based on a general approach to deriving fitness
  functions, selection pressures, and evolutionary dynamics from
  the underlying individual-based stochastic ecological
  interactions and population dynamics. Models of adaptive
  dynamics are classified according to two main dichotomies:
  stochastic vs. deterministic, and polymorphic vs. monomorphic.
  The resultant four fundamental types of adaptive dynamics will
  be reviewed, and their derivations, advantages, and shortcoming
  will be discussed. The talk will then explain how selection
  pressures may drive the increase or decrease of species numbers
  in ecological communities, before highlighting several specific
  examples of community evolution models based on adaptive
  dynamics theory.

  Suggested reading:

  Dieckmann U & Ferriere R (2004). Adaptive dynamics and evolving
  biodiversity. In: Evolutionary Conservation Biology, eds.
  Ferrire R, Dieckmann U & Couvet D, pp. 188?224. Cambridge
  University Press

  
  www.iiasa.ac.at/~dieckman/reprints/DieckmannFerriere2004.pdf