Marie sent me this email about a recent conversation she had with our middle daughter - the 10 year old.
Well, last night, I was looking at a website about Trichoplax adhaerens, a 'wee beastie' I only learned about a few days ago. There was some video of it dividing and Julia watched it over my shoulder. I told her that it is the simplest multicellular animal known, grows up to 3 mm in diameter so it is barely visible to the eye, has only 4 cell types, (gave a comparison to the 200 cell types in humans), and the shortest DNA sequence of any known animal. I pointed out that it was simpler than sponges, which have about 12 cell types. I also mentioned that they have no idea where T.adhaerens fits in the taxonomy, so for now it is in it's own phylum.
Julia pondered that, then asked, "Shouldn't it be in --- I don't remember the name of it but it starts with a P."
I gaped at her. "You mean Protista?"
"Yeah!" she responded."
No," I said. "Protista are mostly unicellular organisms and this is multicellular."
My goodness, that kid is soaking up information like a member of the Porifera (sponges). I used the words in my conversation with her that I have typed above, and she understood everything that I said, or asked for clarification. I told her that for an experiment I am going to collect some sea water when we [next go to] Florida and see if we can get some T. adhaerens. I don't think it will work because the water may be colder than they like (subtropical to tropical), but worth a try. And if that doesn't work, I will hit the pet stores and ask for some salt water samples. Could be interesting!