what happens when a population or group of living things is divided into two separate groups in two separate environments ?
When a population or group of living things is divided into two separate groups in two separate environments, a process called speciation can occur. Speciation is the formation of new and distinct species over time.
Here's an explanation of how this process can occur:
1. Geographic Isolation: The initial step in the formation of two separate groups is geographic isolation, where a physical barrier such as a mountain range, river, or canyon divides the population. This barrier prevents individuals from one group from interbreeding with individuals from the other group.
2. Genetic Drift: In each isolated group, random changes in gene frequencies start to occur independently due to a process called genetic drift. Genetic drift is the variation of gene frequencies in a population due to chance events, which becomes more significant in smaller populations. As time passes, these chance genetic variations can accumulate in each group, leading to genetic differences.
3. Natural Selection: The two groups experience different environmental conditions in their respective habitats, which can result in different selective pressures. Different adaptations may be favored in different environments. Over generations, individuals in each group are more likely to survive and reproduce successfully if they possess traits that are advantageous in their specific environment. This leads to natural selection acting independently on each group, favoring different traits and characteristics.
4. Reproductive Isolation: As genetic and phenotypic differences accumulate over time, members of the two groups may become reproductively isolated. Reproductive isolation means that when individuals from the two groups come into contact again, they may no longer be able to produce fertile offspring due to genetic incompatibility or behavioral differences.
5. Speciation: Once reproductive isolation is established, the two groups are considered different species. They have diverged enough genetically and morphologically that they can no longer interbreed to produce viable and fertile offspring. These new species may continue to evolve independently in their respective environments, further increasing their differences over time.
In summary, when a population or group of living things is divided into two separate groups in two separate environments, the processes of geographic isolation, genetic drift, natural selection, reproductive isolation, and speciation can lead to the formation of two distinct species.