This project, led by Robert Scotland at @OxfordPlants, involved researchers from @OregonState, @Cipotato, @DukeU, @TheBotanics and @KewScience, as well as really important collaborators during field work, herbarium curators, other taxonomists, funders... So much help!🙏
We studied specimens of Ipomoea and related genera (tribe Ipomoeeae, family Convolvulaceae) from all around the world. This, of course, would have been just impossible without an extraordinary resource: HERBARIUM COLLECTIONS!
We obtained DNA from specimens collected during the last 250 years and inferred phylogenies to investigate the evolutionary relationships between species. And guess what? Without taxonomy, 40% specimens in our study would be wrongly identified (👁️Fig. 3b). https://www.nature.com/articles/s41477-019-0535-4/figures/3
Also, check Fig. 3a highlighting 'Ipomoea' species present in Bolivia. A comprehensive study of the entire genus allowed us to identify their close relatives, even if they do not appear in Bolivia.
https://www.nature.com/articles/s41477-019-0535-4/figures/3 (Photo: 'Ipomoea santacrucensis', by John Wood)
🚩IMPORTANT TAXONOMIC RESULT: we expand Ipomoea to include all members of the tribe Ipomoeeae (Convolvulaceae with spiny pollen). Prev. studies suggested non-monophyly of other previously recognised genera & we confirmed it. All nomenclatural changes here: https://static-content.springer.com/esm/art%3A10.1038%2Fs41477-019-0535-4/MediaObjects/41477_2019_535_MOESM1_ESM.pdf
In total, in this project we described 63 new species (10% species of Ipomoea are new!), identified a lot of synonyms (69% rate), lectotypified almost 300 names, published hundreds of descriptions and illustrations and some very useful identification keys. Massive improvement!😄
Ah, don't miss the SPECIES NARRATIVES in the Supplementary Information! We provide ten examples describing how the species discovery process works. Really nice piece to get a sense of what it takes to discover new species. 🏦🔬📚🌿🌿🌿
In terms of evolution, we identified two very diverse American clades with high diversification rates, comparable to some of the most iconic evolutionary radiations in the #PlantKingdom. In the picture, some members of this group (described @KewBulletin: https://link.springer.com/article/10.1007/s12225-015-9592-7).
And, of course, there is #SweetPotato! Important results appeared last year in @CurrentBiology ( https://www.cell.com/current-biology/supplemental/S0960-9822(18)30321-X), e.g. we published a complete phylogeny of all sweet potato close relatives and identified 'Ipomoea trifida' as its closest relative.
Now, we show that:
1) Both species diverged over 1 MYA.
2) Part of the diversity existing within the crop largely predates agriculture.
3) At least 60 other Ipomoea species evolved storage roots over 1 MYA.
4) Many of them are as big as sweet potatoes & edible (📷I. lilloana)
SO:
The storage root in cultivated #sweetpotato is NOT a product of human domestication but rather an existing trait that predisposed the plant for cultivation.

What changes did human domestication produce in the crop then? We will try to answer this question in forthcoming studies.
In conclusion: we can make extraordinary progress in our understanding of world's #biodiversity by integrating specimen-based taxonomy with genomics and phylogenetics. The resources (Natural History collections!) and scientific expertise are already available. Let's do it! 🌎
PS: for those wondering where the ACTUAL taxonomic monograph is, stay tuned. It has been already accepted for publication and will be out soon, full of descriptions, images, identification keys...😄
You can follow @pablomurod.
Tip: mention @twtextapp on a Twitter thread with the keyword “unroll” to get a link to it.

Latest Threads Unrolled: