Can an organism belong to two different species?

No, an organism cannot belong to two different species.

In biological taxonomy, each organism is classified into a unique hierarchical system, starting from the broadest category, the domain, and narrowing down to the most specific, the species. This system, known as the Linnaean system, ensures that each organism belongs to one, and only one, species.

The concept of a species is fundamental to biology. A species is defined as a group of living organisms that can interbreed to produce fertile offspring. This means that members of the same species share a common gene pool. This definition, known as the biological species concept, is the most widely accepted definition, although there are other definitions based on morphology, ecology, and phylogeny.

However, it's important to note that while an organism can't belong to two different species, species can interbreed in some cases to produce hybrids. These hybrids, like mules (a cross between a horse and a donkey), often can't reproduce. This is one of the reasons they are considered separate species.

In addition, the process of speciation, where one species splits into two or more separate species, can lead to organisms that are transitional between two species. However, these are still considered part of one species or the other, not both.

In conclusion, while biology is a complex field with many exceptions and nuances, the basic principle that an organism belongs to a single species remains a fundamental concept. This is crucial for understanding biological diversity, evolution, and the relationships between different organisms.