Evolution is the change in an organism over time. Why does evolution occur? It occurs because life will either adapt or die as the earth transforms. Those who are the "fittest" will survive. Although evolution is just a theory more scientists are coming up with more evidence that supports evolution.
Charles Darwin called evolution "Descent with Modification" or it is referred to as "Gradualism." The mechanism of this is natural selection. Natural selection is when an organism that is best adapted to its environment will survive and reproduce passing favored traits on to the next generation. Darwin used the finches of the Galapagos Islands as an example of evolution. He discovered that there were thirteen varieties of finches each with different variation in beak size. These variations are due to their eating habits. This is Darwin's example of how organisms must adapt to their environment in order to survive. Evolution is the change over time!
Charles Darwin called evolution "Descent with Modification" or it is referred to as "Gradualism." The mechanism of this is natural selection. Natural selection is when an organism that is best adapted to its environment will survive and reproduce passing favored traits on to the next generation. Darwin used the finches of the Galapagos Islands as an example of evolution. He discovered that there were thirteen varieties of finches each with different variation in beak size. These variations are due to their eating habits. This is Darwin's example of how organisms must adapt to their environment in order to survive. Evolution is the change over time!
Do you believe in Evolution...
I believe that evolution is true. With Charles Darwin theory "Descent With Modification" and the mechanism of Natural selection, i find evolution hard not to believe. This being because natural selection is when an organism that is best suited to its environment will be able to survive and reproduce and pass on the favourable traits down to future generations. This is shown by the peppered moths. Before the industrial revolution the moths lived in light forests but then during the revolution the forests began to slowly get darker this caused the moths to adapt. Some changed their colour because of natural selection. After the industrial revolution the majority of the population of peppered moths was dark because of natural selection those who adapted to the dark environment were able to survive and reproduce and pass this trait on to future generations. Not only this but the evidence that has been used the longest also leads me to believe that evolution is true. Fossils are preserved remains from organisms, to show the homologous structures of organisms from a long time ago to ones of today. This shows us how they have evolved over time but also they still have some DNA in common. One other piece of evidence that leads me to believe in evolution is comparative embryology. This allows scientist to see that at an embryo state some organisms you can see they share similar DNA because of their basic and primitive genes. This is why I believe evolution to be true.
Punctuated Equilibrium vs. Gradualism
Gradualism was developed by Charles Darwin. It occurs slowly and it is the change of an organism over a long period of time , through natural selection and variations occur in a species. Whereas Punctuated equilibrium is developed by Eldridge and Gould. Unlike gradualism where the mechanism is natural selection, punctuated equilibrium is opposite those who are less fit but can survive members of the population are pushed to have to adapt to a harsh environment. This occurs very quickly. The peripheral population can end up outcompeting the original population.
A gene pool can change...
There are five different ways a gene pool can change. They are listed below:
1) Natural Selection: Those, who have adapted to their environment and are the fittest will survive and be able to reproduce to pass on their genes.
2) Mutations: A mutation is the change in the DNA of an organism. This change can be passed down to future generations. It can either be positive, negative or neutral.
3) Genetic Drift: Because of random events there is a change in the gene pool.
4) Gene Flow: the shift of genes from one population to the next. This can bring about new variations in a population.
5) Non-Random Mating: It is very rare for organisms to mate randomly. Examples of non random mating are:
Harems; when one male has several females
Assortative Mating; you choose those who are similar to you
Sexual Selection; based on selection criteria
1) Natural Selection: Those, who have adapted to their environment and are the fittest will survive and be able to reproduce to pass on their genes.
2) Mutations: A mutation is the change in the DNA of an organism. This change can be passed down to future generations. It can either be positive, negative or neutral.
3) Genetic Drift: Because of random events there is a change in the gene pool.
4) Gene Flow: the shift of genes from one population to the next. This can bring about new variations in a population.
5) Non-Random Mating: It is very rare for organisms to mate randomly. Examples of non random mating are:
Harems; when one male has several females
Assortative Mating; you choose those who are similar to you
Sexual Selection; based on selection criteria
Dichotomous Key
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