DeLeon said:
The first dot point on my syllabus is
- Outline the impact on the evolution of plants and animals of:
- Changes in physical conditions in the environment
- Changes in the chemical conditions in the environment
-Competition for resources
Can anyone please help give me an example of each that would be useful for study, i have a fair idea on the last 2 but not so sure of what i can use for the first one.
eg of changes in physical conditions
-peppered moths, before there was more light coloured moth because they could camouflage themselves against the lichen on trees, however when the industrial revolution arrived, soot settled on the trees making the light coloured moth easily predated, thus now the variety of the population is pepper coloured or dark coloured.
eg of changes in chemical conditions
-the use of DDT on mosquitoes (DDT is an insecticide), small amounts of this insecticide was used on mosquitoes to get rid of malaria, and it did work for a while and wiped all ALMOST all the population, HOWEVER, the mosquitoes that survived passed their genes onto the next generation and thus they population gained immunity to DDT and soon it became ineffective.
eg competition for resources
-when dinosaurs lived on earth, most of the resources were available to them because they dominated the land. thus, the mammals were scarce in numbers becuase there was not much resources for them to survive on. however, when the dinosaurs became extinct, there was a large incline in number of mammals as they took advantage of the abundant resources and reproduced and the population diversified as a result.
