ADDENDUM FOR BIOLOGY NATURAL SELECTION

Geographical isolation is characterised in this experiment by the difference of the swamp and forest and the existence of a desert in between the two ecosystems. Natural features are the main cause of isolation. These include rivers and mountain ranges. The geographical isolation of landmasses by continental drift is another good example. In general, reproductive isolation is the inability of related or different species breeding due to differences involving many factors. These include geographical, behavioural, physiological, or genetic barriers or differences (isolating mechanisms). Speciation could occur in this simulation in various ways. There are many types or modes of speciation.

Since the yellow frogs in the swamp have very little variation, they will be much less likely to survive when the environment changes. If we suppose the forest became a bush, the frogs would have a higher chance of survival. In our simulation there was no movement between the two ecosystems. If the swamp dried up and became a forest, green frogs would begin living there. Some yellow frogs would travel and live in the desert, by developing resistance against dry conditions. These yellow desert frogs would then reach the now yellow bush, where they will find that they cannot mate with the yellow frogs there or any of the red and green frogs. It is common to be geographically isolated first and then to adapt to different environments and then to be reproductively isolated. This is the process of speciation that could occur with this simulation. This would occur with a duration of many decades. It would be impossible to describe this process using only a decade of time.