Museum bird specimens reveal hidden hybrid genetics across species
Scientists used DNA from museum collections to prove that birds-of-paradise hybridize far more often than anyone realized—even across different genera. The findings could reshape how researchers identify species and understand evolutionary boundaries, with implications for conservation policy and biodiversity assessment.
Originaltitel: Contemporary intergeneric hybridization and backcrossing among birds-of-paradise
<p>Despite large differences in morphology, behavior and lek-mating strategies the birds-of-paradise are known to hybridize occasionally, even across different genera. Many of these bird-of-paradise hybrids were originally described as distinct species based on large morphological differences when compared to recognized species. Nowadays, these specimens are generally recognized as hybrids based on morphological assessments. Having fascinated naturalists for centuries, hybrid specimens of birds-of-paradise have been collected and the specimens kept in Natural History Collections. In the present study, we utilize this remarkable resource in a museomics framework and evaluate the genomic composition of most described intergeneric hybrids and some intrageneric hybrids. We show that the majority of investigated specimens are first-generation hybrids and that the parental species, in most cases, are in line with prior morphological assessments. We also identify two specimens that are the result of introgressive hybridization between different genera. Additionally, two specimens exhibit hybrid morphologies but have no identifiable signals of hybridization, which may indicate that minor levels of introgression can have large morphological effects. Our findings provide direct evidence of contemporary introgressive hybridization taking place between genera of birds-of-paradise in nature, despite markedly different morphologies and lek-mating behaviors. Bird-of-paradise hybrids from different genera can be fertile! Using museomics, we investigate 37 bird-of-paradise hybrids from Natural History Collections. We show that the majority of these specimens are first-generation hybrids and that the parental species, in most cases, are in line with prior morphological assessments. However, two specimens are identified as intergeneric backcrosses. These are the first direct evidence that gene flow between divergent bird-of-paradise species is possible, despite large differences in morphology and lekking behavior. In this study, we use DNA analyses to investigate 37 bird-of-paradise hybrids collected in the wild in New Guinea during the last two centuries. We provide evidence that deeply divergent bird-of-paradise species are able to reproduce with each other in nature despite having very different plumages and mating behaviors, and confirm the identity of the parental species for all except three hybrids. Furthermore, two of these hybrids are identified to be backcrosses, i.e., the offspring of a hybrid mating with a pure species. These hybrids provide the first direct evidence that genetic material can be transferred between divergent species of birds-of-paradise with large differences in morphology and mating behaviors.</p>