BLUEPRINT OF LIFE
1. Evidence of Evolution
Natural selection is a naturally occurring process in which organisms eventually adapt characteristics in order to suit their environment better in order to survive.
An example of this is the peppered moth. First-hand investigation: Peppered moth
Aim: To perform a first-hand investigation to model natural selection.
Equipment: 1 sheet of newspaper, tweezers, 30 small white circles, 30 small newspaper circles.
Method: Circles of white paper and newspaper were cut out and scattered on a sheet of newspaper while one person looked the other way. The person facing away was then given 30 seconds to extract as many circles they could, using tweezers to replicate a birds beak. After counting and tallying the different coloured circles, the experiment was repeated twice more with the same person to play the ‘bird’ to eliminate any discrepancies in results.
Results: It was found that the ‘bird’ extracted more white circles than newspaper ones.
Conclusion: This experiment replicated the real peppered moths extremely well. It proved to be a successful, valid and reliable experiment.
Case study: environmental changes leading to a change in species
The peppered moth is one of the best know examples of natural selection found in England. These moths were originally a light colour (also known as typica) as the trees in the local area had light bark in which concealed them from predators prior to the industrial revolution. The pollution created during the industrial revolution caused the bark on the trees to blacken from the smog. This made the lightly coloured moth easily spotted, thus leading to the change in species to ensure their survival. It was then that people started to notice black moths instead of the peppered moths (these dark moths were also known as carbonaria). These moths were harder to see on the smog-covered trees which saved the species. This was an environmental change that led to a change in species.
Impact on the evolution of plants and animals of:
Changes in physical conditions in the environment – temperature, natural conditions, climate and availability of water
Australian climate has changed over millions of years and as a result has become drier. Australian animals in the wetter times relied on the various selections found on the rainforest floor