Am J Bot. 2022 Sep 27. doi: 10.1002/ajb2.16074. Online ahead of print.
ABSTRACT
PREMISE: Understanding evolutionary history and classifying discrete units of organisms remains an overwhelming task, and lags in this discipline concomitantly impede an accurate documentation of biodiversity and conservation management. Rapid advances and improved accessibility of sensitive high throughput sequencing tools are fortunately quickening the resolution of morphological complexes that generally are underestimating species diversity. This seems to be the case of the persisting taxonomic quandary of the Hairpin Banksias (B. spinulosa sens. lat.), a group of eastern Australian flowering shrubs demonstrating a continuum of morphological diversity from which the critically endangered B. vincentia has been described.
METHODS: To assist conservation while testing the current taxonomy of this group, high-throughput sequencing was used to infer a population-scale evolutionary scenario for a sample-set comprehensive in its representation of morphological diversity and a two-and-a-half thousand kilometer distribution.
KEY RESULTS: Banksia spinulosa sens. lat. represents two clades, each with an internal genetic structure shaped through historical separation by biogeographic barriers. This structure conflicts with the existing taxonomy for the group. Corroboration between phylogeny and population statistics aligns with the hypothesis that B. collina, B. neoanglica, and B. vincentia should not be classified as species.
CONCLUSIONS: The pattern here supports how morphological diversity can be indicative of a locally expressed suite of traits rather than relationship. Over-splitting in the Hairpin Banksias is atypical since genomic analyses often reveal that species diversity is underestimated. However, we show that erring on overestimation can yield negative consequences, such as the disproportionate prioritisation of a geographically anomalous population. This article is protected by copyright. All rights reserved.
PMID:36164832 | DOI:10.1002/ajb2.16074
