BI102

General Biology

Spring 2012

Dr. Brian K. Penney

Goulet 2320

603 641-7149

bpenney@anselm.edu

Brian K. Penney 's web page

---

1. Define a population, population density and different types of dispersion patterns.

   • A population is a group of individuals of a single species that are potentially interbreeding. These individuals are typically influenced by the same suite of biotic and abiotic factors.
   • Spatial descriptors include: Density (individuals per unit of space) and dispersion (how individuals are spaced within their area; clumped, random, uniform or even).

   ---

2. Explain how life tables are used to track mortality and survivorship in populations and describe the three major types of survivorship curves.

   • Population growth will depend on relative birth and death rates, as well as age and sex structure.
   • Mortality and survivorship can be described through life tables or survivorship curves (KNOW THESE TYPES Fig 36.3).

   ---

3. Define and compare the two basic population models and the factors they consider, and compare their predictions to the abundance patterns seen in the natural world.

   • Factors limiting population growth are density-dependent (such as breeding success) or density-independent (e.g. weather).
   • Growth can be predicted via idealized models of population growth such as the exponential population growth model and the logistic population growth model.
   • The logistic model includes both growth rate (r) and carrying capacity (K).
   • Population levels may wander unpredictably or have cycles driven by abiotic factors, predation rates, or a lag in predator's numerical response.

   ---

4. Explain how life-history traits vary with environmental conditions and with population density. Compare r-selection and K-selection and indicate examples of each.

   • Life history characteristics such as number of offspring, timing of reproduction, body size and degree of parental care comprise a species' life history.
   • Many life history traits are under natural selection to provide the maximum number of viable offspring.
   • Strategies range from being optimized for high growth under unlimited resources (r-selected) to being optimized for population maintenance near carrying capacity (K-selected).

   ---

5. Describe two practical applications of population studies.

   • sustainable resource management of fisheries/wildlife resources to find maximum sustained yields.
   • studies to predict resource needs for the future, as human populations have grown exponentially for the last 400 years. An important international consideration is whether countries have undergone the demographic transition, when both mortality and birth rates slow.

Copyright 2007-2012, Brian K. Penney

How to succeed in this course