What a Newfound Kingdom Means for the Tree of Life | Quanta Magazine


That picture “chills” me to the bone!

@joshuahedlund… you are freaking me out … but in a Good Way!

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The microscopic Hemimastix kukwesjijk . . . “… this microbe looks and acts like a miniature ogre, the researchers say, in the way it traps and eats food.”

Now that is grotesque. It hunts it’s food … and they are not willing to categorize it as an animal!

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Totally gross eating habits …

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Are these the “junior-highers” of the protozoic world? : )

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Watch out for science journalism/university press release hype. This group has been known for a long time. What’s new is 1) the ability to culture at least one species and 2) the discovery of how deep its branch is within eukaryotes.


The Spironematellidae Family is quite old… the first genus discovered in 1838, with more findings in 1840 and 1842. And there has been lots of relations found since then.

But this Hemimastix kukwesjijk “ogre” beast … it wasn’t even collected until 2016, and published this year:

“While hiking in Nova Scotia on a cold spring day in 2016, she fell back from her friends to scrape a few grams of dirt into a plastic tube.”

I think we can get a little excited by these latest findings!

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The discovery of a new species of hemimastigote isn’t very exciting. What’s exciting is the first DNA sequence from the group and what it shows.



Right. And I haven’t read that the other members of this group share these genetic characteristics. Of course, this could be just bad reporting habits.

But the article did say that the new creature isn’t related to anything else known on Earth, which I assume means the creatures discovered in the 1800’s and decades ago in the 1900’s are not genetically so distinct.

I agree with you … .it’s not that this is a new creature that makes it important. My only issue was with this sentence:

“This group has been known for a long time.”

It’s not the group I’m excited about. It’s this particular species!

Of course they do.

No, the article is just egregiously wrong on that subject. Nobody has sequenced any other hemimastigote, which is again why the matter is interesting. But “isn’t related to anything else known”? No. It’s a eukaryote. It’s related to all other eukaryotes, and of course to prokaryotes too. It just isn’t very closely related to other eukaryotes. But then again there are a number of other eukaryote groups for which the same could be said. Just deep branches in the tree.

That’s a problem; this species isn’t interesting in itself (well, not more so than any other species) except that it’s a hemimastigote for which there is DNA sequence. Don’t fall for the hype.


What is that number? It’s pretty small, isn’t it? That’s what seems to be part of the hype for me - when I was a kid in the 90’s I read there were five “kingdoms” - so discoveries at this level seem pretty exciting to me - the super-group Archaea being distinct from bacteria is probably the biggest, but newly discovered highly distinct groups with eukaryotes seems a close second.

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I presume you mean “newly discovered to be highly distinct”. How many eukaryote taxa deserve to be called “kingdoms” is a completely subjective decision, one that’s of very little concern to systematists these days. The fashion is for named but unranked clades.

Now, if we consider animals, plants, and fungi all as separate kingdoms and use those as the standard of divergence to qualify, there are dozens of eukaryote kingdoms. Consider, for example, that such a standard would make choanoflagellates a kingdom.


Yes, thanks!

Are these other eukaryote “kingdoms” as internally and comparatively diverse as animals, plants, and fungi, or do we not have enough data to know? It’s hard for me to intuitively grasp things like that because they all just seem like a bunch of tiny microscopic thingamajigs, even though I know intellectually that there’s a lot of complexity…

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It’s hard to come up with a good index of what you’re calling “diverse”. In biology, “diversity” means just a count of species, and while most eukaryote species probably haven’t been discovered yet, I think they may compare in number of species. What you probably mean, however, is what biologists call “disparity”, i.e. the variety of different morphologies and adaptations. Given that they generally have only single cells to work with, I’d say that most of these “kingdoms” do compare in disparity well enough with the other kingdoms too. But again, hard to come up with an index. Eyeball impressions would be highly biased.