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Single cell eukaryotes also exist. Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea? No exceptions at all?
> with eukarya containing all multicellular organisms within the four kingdoms of fungi, animals, plants and protists. This bugs me so much. The four-kingdom system should have died out decades ago, it's absurdly wrong. For one thing, fungi and animals should be together (opisthokonts) if you're dividing eukaryotes into the major groups. If you consider genetics, there's no such thing as "protists", they're just a wh…
My strong impression is that even the roots of the tree are debated, with competing models that often change.
> The four-kingdom system should have died out decades ago
First, hopefully not! :) Second, I think it's used because it's the last stable model. Third, it's a model that the public can understand - theres no point in even trying to use "Archaeplastida, Excavata, SAR supergroup, Amoebozoa, and Opisthokonta" unless you are an expert in phylogenics or evolution. Who can understand and remember that?
> with eukarya containing all multicellular organisms within the four kingdoms of fungi, animals, plants and protists. This bugs me so much. The four-kingdom system should have died out decades ago, it's absurdly wrong. For one thing, fungi and animals should be together (opisthokonts) if you're dividing eukaryotes into the major groups. If you consider genetics, there's no such thing as "protists", they're just a wh…
> All life on Earth is classified within three domains — bacteria, archaea and eukarya — with eukarya containing all multicellular organisms Single cell eukaryotes also exist. Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea? No exceptions at all?
Yes, "with eukarya containing all multicellular organisms" does not mean "all eukarya are multicellular organisms" it means "multicellular organisms are a subset of eukarya".
> Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea?
First off, "prokaryotes (what they call bacteria)" is incorrect. Both archaea and bacteria, in the three-domain model referenced in the article, are prokaryotes.
Second, correct, everything understood as a multicellular organism -- as distinct from colonies of unicellular organisms -- is composed of cells with nuclei, classified in eukarya in the three-domain model.
(There is a newer proposed two-domain model which disposes with Eukarya as a top-level domain, folding it under Archaea; in that model, clearly, there are multicellular Archaea.)
> All life on Earth is classified within three domains — bacteria, archaea and eukarya — with eukarya containing all multicellular organisms Single cell eukaryotes also exist. Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea? No exceptions at all?
They can form colonies and, within groups that share walls, specialize into different functions such as photosynthesis or nitrogen fixing behavior. This enables the colony to adapt to changing conditions that, while still made up of individual organisms, collectively appear to function similarly to a single multicellular one.
With that said, there aren't any examples of truly multicellular organisms within either domain. Just as an ant colony is not a single organism, cyanobacteria colony specializations are not examples of organs.
> with eukarya containing all multicellular organisms within the four kingdoms of fungi, animals, plants and protists. This bugs me so much. The four-kingdom system should have died out decades ago, it's absurdly wrong. For one thing, fungi and animals should be together (opisthokonts) if you're dividing eukaryotes into the major groups. If you consider genetics, there's no such thing as "protists", they're just a wh…
> The exact list is up for debate, and currently undergoing change. My strong impression is that even the roots of the tree are debated, with competing models that often change. > The four-kingdom system should have died out decades ago First, hopefully not! :) Second, I think it's used because it's the last stable model. Third, it's a model that the public can understand - theres no point in even trying to use "Arch…
It's strange to see people promoting it online in 2025. If adults want to remain ignorant, so be it, but at least teach children the truth. Let them know that life is incredibly complicated, it's a mystery we're still solving, and they could be the ones to help figure it out. Don't overly simplify things for small minds, it creates a false picture and it kills the imagination.
> All life on Earth is classified within three domains — bacteria, archaea and eukarya — with eukarya containing all multicellular organisms Single cell eukaryotes also exist. Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea? No exceptions at all?
> Single cell eukaryotes also exist. Yes, "with eukarya containing all multicellular organisms" does not mean "all eukarya are multicellular organisms" it means "multicellular organisms are a subset of eukarya". > Is it strictly true that there are no multicellular prokaryotes (what they call bacteria) or archaea? First off, "prokaryotes (what they call bacteria)" is incorrect. Both archaea and bacteria, in the three…
I suppose it depends on which model you use, and as discussed they seem to vary and be in flux right now, but the three domain model I learned was prokaryotes, archaea, and eukaryotes - the first two being different domains.
> Yes, "with eukarya containing all multicellular organisms" does not mean "all eukarya are multicellular organisms" it means "multicellular organisms are a subset of eukarya".
We agree. I don't grasp your point?
Who knew the internet evolved millions of years ago?
Earlier quoted context omitted.
> The exact list is up for debate, and currently undergoing change. My strong impression is that even the roots of the tree are debated, with competing models that often change. > The four-kingdom system should have died out decades ago First, hopefully not! :) Second, I think it's used because it's the last stable model. Third, it's a model that the public can understand - theres no point in even trying to use "Arch…
Children can memorize all 50 US state capitals, they can memorize a handful of scientific names. If we really wanted to, we could teach them a much more accurate view of the tree of life. Also, I don't think the four-kingdom system has been taught in schools for a while? I went to high school in the late 90s and it wasn't taught then. It's strange to see people promoting it online in 2025. If adults want to remain ig…
Earlier quoted context omitted.
> The exact list is up for debate, and currently undergoing change. My strong impression is that even the roots of the tree are debated, with competing models that often change. > The four-kingdom system should have died out decades ago First, hopefully not! :) Second, I think it's used because it's the last stable model. Third, it's a model that the public can understand - theres no point in even trying to use "Arch…
Children can memorize all 50 US state capitals, they can memorize a handful of scientific names. If we really wanted to, we could teach them a much more accurate view of the tree of life. Also, I don't think the four-kingdom system has been taught in schools for a while? I went to high school in the late 90s and it wasn't taught then. It's strange to see people promoting it online in 2025. If adults want to remain ig…
More personally speaking: what am I missing out by using the four kingdoms? Like, how could that possibly ever backfire in a way that slightly impacts my life negatively, or impedes the scientists studying genetic lineages? There's basically infinite science to "remain ignorant" of, I don't see any justification for an elitist attitude on this nuance in particular.