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The story
A research team led by Associate Professor Shingo Akita of Hokkaido University has announced that four varieties of Japanese kelp long treated as separate names — including Rausu kelp and Rishiri kelp — turned out through DNA analysis to actually be the same species. On the thread, posters listed out the finely subdivided kelp classifications like Ma-kombu and Oni-kombu, and the discussion grew into a debate over the very definition of “species” in biology, with comments like “what’s the difference between a species and a variety?” and “even with identical DNA, the taste and stickiness differ.” Some also noted that Rishiri kelp is known as a premium product, and that the amount of umami varies by region of origin.
Four Kelp Varieties Turn Out to Be the Same Species — Revealed by Hokkaido University Team’s DNA Analysis
Among the kelp growing in Japan’s seas, four varieties that had been called by separate names turned out to actually be the same species.
A research team led by Associate Professor Shingo Akita (phycology) of Hokkaido University compiled these findings based on DNA analysis.
Source: asahi.com / Original article here
What people said
That'd be Ma-kombu ("true kelp")… people have been saying that for a while
Genus Laminaria (kombu) — 13 species:
【Ma-kombu (incl. Yayan-kombu)】, 【Hosome-kombu】, 【Rishiri-kombu】, 【Oni-kombu (incl. Rishiri-type Enaga-oni-kombu and Kukinaga-kombu)】,
Enaga-kombu, Mitsuishi-kombu, Naga-kombu, Gaggara-kombu, Karafuto-kombu, Chijimi-kombu, Karafuto-tororo-kombu, Endou-kombu, Gohei-kombu
Does that mean the ones in【 】brackets are all the same species, and the differences come down to habitat?
Re: #7
Doesn't "variety" imply there's a genetic difference though?
By the way, with dogs too — apart from wolf-type dogs like Siberian Huskies and the Chow Chow, pretty much all the rest are variants of the same species.
Do you think DNA analysis is some kind of cure-all?
Clones or identical twins have identical DNA, but are you saying even a single base-pair difference makes it a different species?
This is about how much variation you allow and how much you don't allow —
it's a matter of definition, that's all.
Four kinds of kelp turn out to be the same kind, I wonder why♪
I wonder why♪ I wonder why♪ Why oh why is that♪ (riffing on the Tunnels comedy duo's novelty song "Nande Darou")
If that's the case, it might be fine to keep different product names, but I'd appreciate it if they'd label it alongside like "(Ma-kombu)" or "(snow crab)," just to be clear.
Every now and then someone says that.
Background and Key Points of Debate
Kelp (genus Saccharina, commonly called kombu) has long been finely classified as a Japanese seafood product, but many of those classifications were empirical distinctions based on region or shape, with little genetic backing. What’s new about this study is that it revisited the classification using the objective method of DNA analysis. That said, the very definition of “species” is prone to disagreement in organisms where reproductive compatibility — the usual yardstick for animals — is hard to apply, and the thread raised exactly that point, debating the difference between “variety” and “species” and the difficulty of judging species given seaweed’s unique ability to reproduce through regeneration and fragmentation. It’s also worth noting — something the article itself doesn’t get into — that even kelp genetically identical as a single species could still end up marketed and labeled under different product names, given differences in umami content by region.
*This article is excerpted and summarized from the 5ch (Science News+) thread “[Biology] Four Kelp Varieties Turn Out to Be the Same Species — Revealed by Hokkaido University Team’s DNA Analysis.”
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