Natural Selection Biology

INTRODUCTION:

Natural selection is a process of evolution this occurs due to both biotic. Natural selection is the survival and reproduction of individuals with different phenotypes. In some cases natural selection can be directly observed, Data from the Earth Watch Institute show birds beaks from the Galapagos Islands being naturally selected for throughout different environmental changes such as, after droughts occur and the islands are dry the bird population has stronger beaks which allows them to eat tougher seeds .

Human activity has also lead to changes to the environment that have caused populations to evolve through natural selection. An example of human activity effecting evolution is; around the year 1850 in the United Kingdom,

As stated in my hypothesis stick insects complementarily coloured to the habitat will camouflage, however, this hypothesis was untrue as the green environment did not select the green stick insects for survival. Instead the brown stick insects were selected for as they were very hard to see, and therefore survived. All of the other insect species were contrasting in colour against the green when they were scattered throughout the grass habitat, making them easy to see and therefore easy to pick up. The gravel habitat also selected for the brown stick insects, the habitat already had a lot of brown coloured sticks which looked identical to the stick insects. This made it very hard to see the brown species and allowed them to survive at an increased rate. The red coloured insects has a final population of zero, because of the deep red colour, which made them easy to identify against the orange pebbles. The bark/leafy habitat was made up of dark black dirt, green foliage and fallen yellow and brown decaying leaves. When brown toothpicks made up the majority of the population by the third trial, it was clear that the brown was the hardest to see when placed in the

Natural selection is the name given to the development of species where they adapt their environment increasing the chances of survival and therefore allowing them to further produce offspring. As a part of evolution animals have the ability to alter their colour to better suit them to their environment. The stick insects placed in the environment were contrasting colours of the environments except for the brown stick insects who camouflaged in all habitats. An example of this is the Peppered Moth. The Peppered Moth are normally a grey colour with black speckles, but a genetic mutation can cause them to have black wings. The white moths found it easy to camouflage with the trees before the industrial revolution compared to the black moths, and therefore the black moths suffered from predation. During the industrial revolution, the air became polluted meaning that the darker coloured moths were harder to see. The black moths therefore had the favourable genes, allowing them to reproduce and increase in population. Therefore, this is a prime example of Natural