Not One But Two: The Story of a "Tree"

Environmental & Science Education, STEM, Biodiversity, Nature, Culturre

Ed Hessler

The British journal Nature has a nice story about a tree that is really two trees--two separate species long thought to be a single species. 

This is based on two pieces of evidence. The Iban and Dusan on the island of Borneo have long called the tree by two names and now a genetic study shows the same difference and the standard scientific taxonomy will change. Two lines of evidence finally converge. 

The scientific paper on the molecular biology evidence was published in Current Biology and may be read online. The following is from the main text of the scientific paper.

"The Iban people of Sarawak recognize two species. Lumok is the cultivated tree, with large leaves, thick twigs, large sweet fruits with thick pulp, and short hairs on the buds and young twigs. Pingan is a wild tree with smaller leaves, slender twigs, smaller, less-sweet fruits with thinner pulp, and often, but not always, long hairs on vegetative parts (Figure S1...). An ethnobotanical study recorded names reflecting their close affinity: lumok amat (‘true lumok’) and lumok pingan

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. The Dusun of Sabah also recognize two entities: timadang, equivalent to lumok; and tonggom-onggom, equivalent to pingan. (Figure S1 shows the fruits as well as other details.) ...

"Considering both the Iban and Linnaean systems, we sequenced DNA microsatellites and used targeted capture sequencing to test these hypotheses: first, Iban pingan is genetically distinct from lumok; second, the long-haired ‘barbatus form’ is genetically distinct from the typical short-haired form; third, pingan and lumok correspond to the barbatus and odoratissimus forms, respectively; and finally, pingan is the wild progenitor of cultivated lumok. (My emphasis)

"Tissue was collected in Malaysian Borneo and sampled from herbarium specimens covering the entire species range, including Beccari’s types from the 1860s. Field identification was provided by Iban authors JT and SN in Sarawak and by Dusun authors PM and JJ in Sabah." The full names of the authors may be found at the Current Biology link above.

Freda Kiefer, writing for Nature News is probably more accessible to the general and interested readers  which  recommend  reading it, including at the top two photographs of the fruits. I include some of Freda Kiefer's  comments from that essay, quotes mostly that further inform this lovely study.

--In conversation with Eliot Gardner, international Center for Tropical Botany, noted that he said "This reclassification exemplifies how Indigenous knowledge can change and strengthen our understanding of biodiversity."

--"Gardner says the team thought to investigate whether these were separate species only because the local botanists had used different names. He adds that science has a long history of benefiting from Indigenous knowledge — for instance, scientists often rely on local guides to help make sense of the world around them." Gardner also noted “'It’s not surprising at all that people who are around these plants all day long know them in a more intimate way than scientists who just come into the field from time to time.'”

--"Interacting with Indigenous knowledge on an equal footing could help scientists to learn more about the natural world and how to protect it, says Gardner. 'We can’t conserve what doesn’t have a name.'” 

The quote by Gardner is important I think since it emphasizes the importance of names.  I also wondered how many scientists had  studied these trees in the field, and how they wondered, if they did, about the different names. And it is another example of how current science works, one of which is paying attention to local lore and natural wisdom. 

Of course there is more in both the essay and full paper. I hope you take a look at one or the other or both.