Soortig

Soortig is a term used in evolutionary biology and taxonomy to refer to populations, lineages, or organisms that are notably similar to a particular species but do not meet formal criteria to be classified as that species. The word derives from Dutch, combining "soort" meaning kind or species with the suffix "-ig," indicating likeness or having the qualities of.

In use, een soortig describes phenotypic similarity or genetic resemblance that crosses species boundaries, often resulting from recent divergence, hybridization, or introgression. It is not a formal taxonomic rank and does not imply a specific status under the standard species concepts. Instead, it serves as an informal, descriptive label that can frame questions about whether two populations should be considered the same species or treated as distinct lineages.

Soortig is typically employed in discussions of speciation, hybrid zones, paleobiology, or microbial taxonomy where species boundaries are ambiguous. It helps researchers communicate about gradations of similarity without prematurely assigning formal taxonomic names. However, the term is subjective and its meaning can vary among researchers, so explicit definition within a study is important to avoid ambiguity.

Compared with subspecies, varieties, or ecotypes, a soortig designation is non-rank-based and often provisional, pending additional data such as detailed genetic analyses or reproductive assessments. Critics argue that it can hinder clear communication if not clearly defined, while supporters view it as a useful interim concept in complex or poorly resolved taxonomic landscapes.