•E.g. antibiotic resistance
oBacteria that is resistance to one will not be resistance to the one anymore
oNatural selection can cause the frequency of antibiotic resistance in bacteria to
increase over time
•Organisms evolve or change over time – it is a mistake to view them as static. Evolution is an
ongoing process because organisms continually face new challenges from changes in both the
living and nonliving components of their environment.
6. Communities and ecosystems change over time
•They change over time; not static
•We are often biased by our own time scale on which we operate.
•Ecosystems change over time. When we look at the world as we know it, it is easy to forget how
past events may have affected our present, and how our present actions may affect the future.
7. Spatial scale matters
•How we organize the ecological system
•E.g. physiology ecologist often study at the level of organism and advance to population,
community, ecosystem and finally biosphere
oHow we define each of these level
oHow this hierarchy system constructed
oUsually people are specialized in one specific area
•Organism < population < community < ecosystem < biosphere
oPopulation: group of individuals of same species that are living and interacting in a
oCommunity: association of population of different species in the same area.
•Spatial definition could be complicated because of migrations, so their boundaries are hard to
oMetapopulation : consists of a group of spatially separated populations of the same
species which interact at some level.
Address the connection between different populations
•Abiotic and biotic environmental conditions can change dramatically from one place to another,
some across very short distances. This variation matters because organisms are simultaneously
influenced by processes acting at multiple spatial scales, from local to regional to global.
Ecological studies often include both the biotic (living components), and abiotic (physical components) of