Question

For you, me and everyone else who spent their Intro Biology days dutifully memorising that sponges (Poriferans, to be taxonomically precise) are the oldest, most basic multicellular animals - and who dutifully turned around and now spends their time tutoring it here on OpenStudy...

Answer 1

New research casts that widely taught biologic 'fact' into doubt.

Long story short, scientists finally sequenced some genes from a comb jelly - which is not a jelly fish proper (Phylum Cnidaria) which are relatively nasty creatures named for spear-like stinging cells, but a few exceptional creatures from Phlyum Ctenophora - and found that these comb jellies are actually likely the most primitive and oldest living animals. An honour that for the last hundred years has almost without thought been given to sponges.

I have always loved that these so called biologic truths that have been taught and memorised as truths and are written down in millions of textbooks can be blown to dust by a relatively mundane, routine piece of research like this little sequencing project.

And I am glad that I am descended from a Ctenophore or Ctenophore like animal. They are one of the few pretty marine species that live in my part of the world - we have a common species up to 10 cm in length, and on summer nights you can hang your feet off a dock and see them glowing pink and yellow in the black water - and compared to proper jelly fish, they lack stinging cells and are harmless, benign animals.

A lay person's approach to the paper can be found: http://www.the-scientist.com/?articles.view/articleNo/38619/title/A-New-Basal-Animal/

The results are reported in: J.F. Ryan et al., “The genome of the Ctenophore Mnemiopsis leidyi and its implications for cell type evolution,” Science, doi: 10.1126/science.1242592, 2013.

And attached is a picture of one of the little buggers.

From now on the official stance in the biology group on OpenStudy, when every question in every test bank out there says we are descended from Poriferans, is to explain that actually the test is wrong. With further evidence, we are descended from Ctenophorans.

Answer 2

Omg! So amazing, thanks for sharing this information.

Answer 3

You're quite welcome. :P I hope others enjoy it as much as I do.

Answer 4

omg....we are so mistaken about these facts..thanks @blues

Answer 5

WOW ..really nice information ...........thank u :)

Answer 6

well done :)

Answer 7

Oh Wow - THANK YOU BLUES!
This Was Indeed Very Interesting! Looks Like You Do Learn A New Thing Everyday!

Answer 8

Such a important info , Thank u so much @blues ..
I learn everyday new things here .Thanks OS too . :)