Organisms life cycle
Bladder wrack for example has a relatively simple life cycle. Many other algae have a more complicated life cycle where two or three generations occurr without the repetition of a development stage. The different generations can have varying appearances and the switching from one generation to the other is accomplished with spores and in other cases with eggs and sperms. Although those specie that have heavy and sticky spores and eggs have a tendency to spread badly, they can still give rise to widespread populations when specie, whole or part of, drift into new areas.
Animals can also have fairly complicated life cycles and certain larvae can survive several weeks in the water, while certain other animals do not have a pelagic larvae stage.
Organisms ability to spread is not just of importance for where they can exist, but also for how they adapt to different environmental conditions. Good distribution ability can counteract the occurrance of special adaptions to environmental conditions, while a limited distribution allows a local population to gain special and perhaps unik characteristics that function well in the immediate environment.
|Cliffs and rocks are fantastic!|
|Zoning and flecked occurrence|
|Animals that are attached|
|Variation and change|
|Variations in water level|
|Both cliffs and rocks|
|Freshwater and saltwater|
|Geography, climate and history|
|Organisms life cycles|
|Organisms effect on each other|
|Energy and the flow of material|