Evolution
- The allele frequencies (within the gene pool) of a population can change over time due to processes such as natural selection
- When the allele frequencies of a population change sufficiently over time, the characteristics of the species will also change
- These changes can become so great that a new species forms
- This process is known as evolution
- Evolution can be defined as:
The formation of new species from pre-existing species over time, as a result of changes to gene pools and allele frequencies from generation to generation
- The formation of new species via the process of evolution has resulted in a great diversity of species on planet Earth
- Theoretically, at the origin of life on Earth, there would have been just one single species, to begin with
- This species evolved into separate species (i.e. new species)
- These species would then have divided again, each forming new species once again
- Over millions of years, evolution has led to countless numbers of these speciation events, resulting in the millions of species now present on Earth
Evolutionary change over a long period of time has resulted in a great diversity of species
- The evolution of a new species can take a very long time and many generations
- For organisms with a short generation time (such as bacteria), evolution can be observed far more quickly
