* Species Definition: A species is defined as a group of organisms that can interbreed and produce fertile offspring. This ability to interbreed is a key factor in defining a species.
* Gene Pool: A gene pool refers to the total collection of genes within a population of a given species. It represents all the possible alleles (different versions of a gene) that can be passed down from one generation to the next within that species.
* Genetic Isolation: When two species diverge, they undergo genetic isolation. This means that they are no longer able to interbreed and share genes. Over time, their gene pools become increasingly distinct.
Example: Humans and chimpanzees are different species. While we share a common ancestor, our gene pools have diverged significantly over millions of years of evolution. This divergence is why we have distinct physical and genetic characteristics.
Exceptions:
There are some exceptions to this general rule. For example, hybridization can occur between closely related species. This can temporarily create a mixed gene pool, but it's not a sustainable long-term situation.
In Summary:
Individuals in different species have distinct gene pools because they are reproductively isolated. The concept of a shared gene pool is only applicable within a single species.
