My latest Seed column slipped quietly onto the interwebs last week — it's an overview of how the glues that hold multicellular organisms together first evolved in single celled creatures, represented today by the choanoflagellates.
Just as a teaser, the next print edition that should be coming out soon will continue the focus on enlightening organisms of remarkable simplicity with a description of the results of the Trichoplax genome. Get it! You will also be rewarded with a great issue focusing on science policy.
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What are the key innovations that led to the evolution of multicellularity, and what were their precursors in the single-celled microbial life that existed before the metazoa? We can hypothesize at least two distinct kinds of features that had to have preceded true multicellularity.
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Would you believe that Nick Lally has responded — well, reacted might be the better word — to our criticism of his silly letter? This is a reply to one of the editors to whom he had sent his original mail.
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Every time I talk to creationists, I'm always stunned at the depth of their misconceptions. There are always the same old boring arguments that are ably dismissed with a paragraph from the Index to Creationist Claims, but there are also occasions when they get, errm, creative, and unfortunately…
Another outstanding article, PZ! I just got SEED renewal notices for subscriptions that I send to relatives for the holidays. I'll definitely be renewing them again!
I wasn't going to link over to the article as I feared it would be to technical for me, but I'm so glad I did. I understood it! I never knew I was, literally, stuck together.
"enlightening organisms of remarkable simplicity"
This organism of remarkable simplicity thanks you for this opportunity to enlighten itself.
(Or is that what you meant? :))
Interesting article - another piece of the evolutionary puzzle. Thank you for the link. Stuff like this drives me nuts, because I always end up with a bunch of questions at the end (i.e. can they unstick after they form a colony, what is the mechanism behind that, does that mechanism apply to multicelled organisms..)...sigh..and my university biology days ended almost 30 years ago.
Minor typo: "These organisms are pf great interest".
Sorry, it just caught my eye.
One of the things that anti-evolutionists get caught up on is something like "how can everything hook up if one part changes?" I didn't understand myself, when I first saw the argument, how to respond to that. But understanding that the process of development is itself a matter of cells coordinating by way of very ancient chemical signals is the key.
Maybe we need a developmental biology for dummies that could be pointed to. And I don't mean a book (as excellent as the works of Carroll, Shubin, Zimmer, etc. are), I mean a basic article that is so simplified that even someone with no advanced biology study (such as myself, before reading Zimmer, Carroll, LeRoi, Shubin, etc) can understand what's going on.
Very nice, very clear, but--wow!--brief! That wordcount is a constraining format, so kudos for packing in enough information to make it intellectually satisying.
hey have you seen that video showing sarah palin being pranked by fake nicolas sarzozy. she laughs at canadian yearly seals' massacre.
I liked the glue, nails and cathedral analogy. Solid and creative writing as usual.
Now where's "Natural Revelation?" I want to pre-order now.
Oh Spore Magazine, you mean that thing this whole blogging edifice belongs to? Yeah, maybe I should check them out.
Ignore my comment at #9,
Apparently my brain not work so good today.
Damn! What a wonderful article. Thanks so much.
MOAR!
Mine too. Does Seed lack proof-readers?
And me. This is such an easy one for a spell checker that it is hard to imagine how it got by.
Correct spelling is one of the building blocks of language. Makes me think of a marble cathedral dome with one block slightly off in colour.
Everything else in the article is most excellent, at all levels.
The computer I usualy use has a spellchecker in the taskbar I've been trying to get one on this one without success. Yu know a person can have problems with spelling without being an idiot. It can be a mild touch of dislexia
Even the level of cellular integration of Trichoplax is hard to understand. Not surprisingly, most scientists favour other pluricellular models such as slime molds.
However, the history of Trichoplax science speaks volumes about our knowledge of life diversity:
Trichoplax was discovered growing on the walls of an aquarium in 1883 by F.E. Schulze, a German scientist who provided a thorough morphological description. While Trichoplax was recognized as distinctive when first described, its status as an outlier became increasingly clear as the bounds of metazoan morphological diversity came to be well known. However, early in the 20th century Schulze's work was submerged and erroneous reinterpretations of Trichoplax as a hydroid, or even a sponge larva, made their way into textbooks and journal articles. This recasting of Schulze's results was possible only because no further discovery of the animal itself was reported for over 70 years. Then, in 1969, the noted German protozoologist Karl Grell redis-covered Trichoplax in Red Sea algal samples. Over the next 2 decades Grell and his colleagues systematically investigated several features of the animal's biology. In the years since, various invertebrate zoologists have collected Trichoplax, but with the exception of the original Grell isolate, there has been no systematic effort to collect and establish new clones in laboratory culture. (Peabody at Yale University)
Would someone be kind enough to compare SEED to the magazine NEW SCIENTIST, reading-level-wise and so forth?
I realllllllly liked NEW SCIENTIST & considered it my replacement for what SCIENTIFIC AMERICAN used to be like in the 1970s, but then I realized it was a product of the $%)*@#!#!@^ Elsevier publishing juggernaut and dropped my subscription. That may be naive, but ... :: sigh ::
Anyway, I'd be interested to know because I keep seeing the ads for SEED here ... if anyone has the inclination to make such a comparison, I'd be grateful.
What's wrong with Elsevier?
Re: Elsevier.
I am a fan of John Baez' "This Week's Finds in Mathematical Physics" column:
http://math.ucr.edu/home/baez/README.html
He has a whole section called "Nasty Stuff" and overpriced journals/books is one of the targets there. I decided (based also on my own experience purchasing stuff for university library collections) to join his Elsevier boycott. He describes the whys and wherefores here:
http://math.ucr.edu/home/baez/journals.html
... me, I'm uncomfortable with giant conglomerates of all kinds and dislike giving them my money ... so try to avoid doing so. I know it is becoming all but impossible to follow such a thing 100% but this was an area where I felt strongly and so ...
I was particularly a fan of the "How We Evolve" article.
http://forthesakeofscience.wordpress.com/2008/10/29/how-we-evolve/
I liked The Mason's Apprentice so much I sent PZ a long, rambling email about it. Now that I can link to it I'll be putting up a blog post as well.
As to Trichoplax, it's amazing how simple an animal can get.
Where the typo is concerned, it's not always the author's fault, or the fault of the magazine. More often than you think it's the printer who makes the mistake.
For PlainJane, #4
Good question. I do know that of the four slime mold kingdoms (one bacterial) three of them (one bacterial) go through the same life events; independent units in a loose organization, an aggregated 'slug', then a base with fruiting bodies where spores are produced and then cast wide. At the end of which the original organism dies. Trichoplax might be an advanced slime mold that cut out parts one and three.
#16
Quartermass, some good news for you: Elsevier is selling off New Scientist, or least the company that NS is part of.
We (NS) very seldom had any direct dealings with Elsevier anyway.
I'll leave it to others to compare us to Seed
...but it almost certainly isn't. Genetically it's clearly allied with the early branches of the true animals, not with slime molds.
Sven DiMilo, #22
Now it's clearly allied with the other animals; after all, a lot of time has passed since the possible split between slime molds and animals. There is nothing that says that "less advanced" life forms can't keep evolving.
Just remembered this . . .
What if Trichoplax is a recent descendant of an independent cancer (cf Canine Transmissible Venereal Tumor)?
Hey PZ, Thanks for the press. I just wanted to point out a technical detail. To the best of our knowledge, Monosiga brevicollis does not have integin proteins, but integin domain containing proteins. Also, at this point the cell biology of colony formation is poorly understood, while agreggation is a possibility, colony formation through cell division is also possible and potentially more exciting. Thanks again for the press and I will keep you posted on the advances in our research.
Hey EvoStevo,
No, I'm pretty sure choanoflagellate colonies form by aggregation -- making them a less relevant 'system' for studying animal origins than, say, sponges.
See ya in lab.