<scp>FTIR</scp> spectroscopy in the taxonomy of macro‐organisms: a review

Abstract Traditionally, morphological characterization has served as the primary method for species identification; however, it often fails to distinguish cryptic species or organisms with overlapping phenotypic traits. Modern techniques, though available, are frequently expensive and time‐consuming. In this context, Fourier transform infrared spectroscopy (FTIR) has emerged as a promising alternative. This technique is cost‐effective, provides rapid results and requires minimal sample preparation. Each organism exhibits a unique vibrational spectral fingerprint, enabling reliable classification when coupled with multivariate analysis. This review explores the application of FTIR spectroscopy in the taxonomic identification of macro‐organisms. We highlight its ability to generate distinct vibrational spectral fingerprints, and when coupled with multivariate statistical tools, such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), can effectively differentiate taxa at the family, genus and species levels. The analysis also evaluates common software platforms for spectral processing, assessing their suitability for biological classification. The reproducibility and discriminative capacity of spectral data demonstrate its value in resolving taxonomic relationships and contributing to spectral library development. These insights underscore the broader potential of FTIR spectroscopy in supporting global biodiversity conservation, ecological research and environmental assessment initiatives.