Population Dynamics. Evolution, Natural Selection, and Human Impacts for Introduction to Environmental Science. Population Levels. Population Density – is the number of individuals of a population at a given time.
Evolution, Natural Selection, and Human Impacts for Introduction to Environmental Science
The population growth rate swings based upon biotic and abiotic factors leading to growth or decline
A balance is considered Zero Population Growth (ZPG)
What are the implications of ZPG?
Data from J. Kimbell, 2006, Biology
This shows the growth of Japan and approach to meeting its carrying capacity.
*Carrying Capacity:A Model with Logistically Varying Limits by
PERRIN S. MEYER1 and JESSE H. AUSUBEL2 in Technological Forecasting and Social Change 61(3):209-214, 1999.
Carrying Capacity and J shaped growth carrying capacity
Curve demonstrating the population of rabbits carrying capacity
*MIT System Dynamics in Education Project Under the Supervision of Dr. Jay W. Forrester by Leslie A. Martin
This shows exponential growth leading to overshoot and carrying capacity
Population dieback of species like the reindeer in Alaska
Density-Independent carrying capacity factors affect populations regardless of the size like natural disasters and use of chemicals (like pesticides causing cancers, etc…)
- include many invertebrates and other animals that produce enough offspring to preserve their genetic variability
- few offspring with high survivorship includes a high degree of parental investment to insure offspring success
- examples include many mammals (i.e., humans, marine mammals, river otter, etc…)
r- and K- selected Organisms carrying capacity
Courtesy of www.bio.indiana.edu
These could be done regionally for human age population studies
Classic survivorship where I is a curve representing a carrying capacity
Late loss population; II is a Constant loss like songbirds; and
III is an Early loss curve like those that are r-strategists
posted by carrying capacityBruce W. Grant, Department of Biology,
Widener University, Chester, PA 19013
Courtesy of http://facstaff.uww.edu/wentzl/modes.html carrying capacity
www.indiana.edu/~curtweb/Research carrying capacity
Mass Extinction Epochs in Millions of Years Ago carrying capacity
We must work with, rather than against, our evolved tendencies.
Eliminate selfish genes
SEM of lichen: the linear fungal hyphae and the roundball-like algal groupings.