Principles of Ecology

There are various mechanisms involved which are part of evolution, these include;

• Natural Selection

• Mutation

• Migration

• Genetic Glow

 

Natural Selection

 Natural Selection is said to be Darwin’s most well-known

theory asit states that the evolutionary changes come from
the production ofvariation in each generation and different survival of individual species
themselves, in which they differ in characteristics, meaning that some species will have an increased chance of survival with stronger characteristics in comparison to others, that may be much weaker with less chance of survival (Christ’s and Project, 1999). When understanding natural selection, there is a continuous variation in traits with different species for example beetles. There are both green and brown beetles but green will become selected against the other because they are eaten by birds and therefore survive to reproduce less often than what brown beetles do.

 

Due to their differential reproduction, the environment cannot support limitless population growth of them, meaning that not all individuals are able to reproduce to their full potential, which then causes the decrease of the one coloured beetle and the others continue to reproduce because the trait has a genetic basis (Natural selection, 2015).

 

Genetic Mutations

Genetic mutations  are usually the transmissible change of DNA within a particular cell or organism, which mainly involve the structural change of them that can or cannot be hereditary (Mechanisms of evolution: Mutation, 2007). Although mutation occurs, it may not always be a bad outcome for species this is due to it occasionally being crucial in speciation, this is because the reproductive barriers in some species cannot be generated without mutations (Nei,Nozawa and and, 2011), such as creating new genes to form either different plants or species. For mutations to be inherited, it must occur in the genetic material of a gamete (sex cell) (Modern theories of mechanisms, 2015).

 

Genetic Flow
Genetic flow refers to the movement of genes within a gene pool of one population into that of another. Gene flow increases biodiversity and acts against different speciation pressures which is achieved by rendering two populations more similar to one another

(Mechanisms of evolution: Gene flow, 2007).

A gene pool is the variety of genes which equal to the genetic

code for characteristics, referring to DNA.

Genetic drift describes the random fluctuations in the numbers of

gene variants within a population.

It is mainly common after population bottlenecks, which are the

events that drastically decrease the size of a population.

Although genetic drift plays a major role in the evolution of new

species (Nature, 2015).

The bottleneck effect is what describes the genetic drift which

 occurs when populations go through a traumatic event/destruction,
where a random majority of the population does not make it through (Shmoop biology, 2015).

 

Migration

In relalation to Gene flow, A population's genetic variation changes as individuals migrate in or out of a population and when mutations introduce new alleles. The immigration and emigration of populations not only changes the structure of genes within organisms but also help introduce a wider variety of genetic variation to populations which may be located in other locations and/or habitats (Boundless, 2015). Migration is the movement of a group of animals from one place to another and in most circumstances they return back again, commonly seen when seasonal changes occur (Animal migration, 2015). Migration is commonly an adaptive response to the seasonal or geographical variation of resources, such as temperature changes or decrease in food supplies (Nebel, 2010).
Some species travel relatively short distances to find food, although they usually want to migrate to further for more favourable living or breeding conditions. An example of migration may include the little brown bats – these live in trees in the warmer months, but when it is the weather is colder, they migrate to caves where it is a lot warmer (NatureWorks, 2015).