What is Fitness?

  • An organisms ability to produce offspring. Relative amount within population (compared to others within the population).

Infanticide-The killing of infants in many different species for different reasons. (Lions, Hanuman langurs)

Why does this happen?

  • In the 1850’s it was proposed that this could be for population regulation, but this does not help the population.

Hypothesis to explain infanticide

  • The pathology hypothesis
  • The population regulation hypothesis
  • The quicker reproduction hypothesis

The six basic steps in hypothesis testing:

  1. Observe an interesting pattern- male lions kill cubs
  2. Determine question of interest- why do male lions commit infanticide?
  3. Determine the hypotheses- males kill infants to get a female to come back into estrus sooner so he can now mate with her
  4. Make predictions (“if…then” statements) – if male lions kill infants to gain access to females, then the cubs he kills should not be related to him
  5. Design, conduct and analyze experiments- collect blood samples of cubs and male lions, test paternity
  6. Evaluate the hypothesis