Tardigrade (AKA Water bears)

[TinfoilCat]

Has anyone heard of the claim that Tardigrades are "aliens"?

These unique microscopic animals are quite fascinating, but many believe that these animals came from a different planet. Tardigrades are known for their resemblance to bears and of their unique nature.

Oddities of Tardigrades:
- Their eggs look like miniature pieces of art.
- They are composed of many organs such as a brain.
- They seem to be anywhere with water. (At least 10 meters from you)
- Are able to withstand "any extreme condition."
- Are able to shrivel up and dry for a long periods of time without food and needs a drop of water to revive itself. :jaw-dropp
- Etc.

A space program was launched to see if they can exist in space. Anyone hear about the results? :confused:
blog.wired.com/wiredscience/2007/09/can-the-worlds-.html

Is this woo or not?

[sanguine]

Has anyone heard of the claim that Tardigrades are "aliens"?

These unique microscopic animals are quite fascinating, but many believe that these animals came from a different planet. Tardigrades are known for their resemblance to bears and of their unique nature.

Is this woo or not?

It's woo, unless you believe that aliens will use the exact same biochemistry and genetics as life on earth, and that those aliens will be closely related to insects and other arthropods.*

This paper from Ryu et al shows that regions of the mitochondrial DNA in tardigrades look like regions of mitochondrial DNA in arthropods.

http://www.ncbi.nlm.nih.gov/pubmed/18182850?ordinalpos=5&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

This paper from Jonsson and Schill looks at Hsp70 in tardigrades -- Hsp70 is a protein common to a whole bunch of life on earth:

http://www.ncbi.nlm.nih.gov/pubmed/17261378?ordinalpos=10&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

This paper from Gabriel and Goldstein looks at common developmental genes found in tardigrades and arthropods:

http://www.ncbi.nlm.nih.gov/pubmed/17516081?ordinalpos=8&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum


*As a biologist, I think the first non-Earth life we encounter will likely be microbial and use biochemistry similar to that found on Earth and genetics that are utterly incompatible with that found on Earth. I certainly don't think they'll plug neatly into the evolutionary tree next to insects, of all things.

[Goshawk]

A space program was launched to see if they can exist in space. Anyone hear about the results? :confused:
blog.wired.com/wiredscience/2007/09/can-the-worlds-.html




The tardigrades went up, the tardigrades came back down, (http://www.bio-pro.de/en/region/stern/magazin/04196/index.html) results hoping to be published in "August 2008" but if it is, it isn't on the Internet yet. Team leader. (http://www.uni-tuebingen.de/Physiologische-Oekologie/schill/schill.html) If you're really interested, you could send him an e-mail.

ETA: They rode up on a Russian launch; it wasn't an entire space program just for them.

[bellonax]

Ooh, if you hear anything, let us know. This sounds very interesting.

[sphenisc]

ETA: They rode up on a Russian launch; it wasn't an entire space program just for them.


It was a 60 micron step for a tardigrade, a great leap for tardigrade kind!

http://pathfinderscience.net/tardigrades/cbackground.CFM

[Kotatsu]

Interestingly, one of the greatest authorities on Tardigrades (allegedly) is something of a character when it comes to believing outrageous things. I don't know the details, but he's involved in that space program in some manner.

I met him last autumn on a PhD course in meiofauna, and when we had a large lobster dinner one evening (1), he (and most of the other professors and stuff) got quite drunk, and started talking about how the Vikings discovered not only North America, but also South America, where they apparently were crowned kings of the Incas for a while. They also made a very detailed map of the entire American west coast, which was somehow stolen by the Pope. According to him, this was a quite common belief in Denmark, though I don't know how reliable that would be.

Both Iceland and Denmark, he said, had put official pressure on the Pope to release the map and send it to either of those countries, but to no avail. Supposedly, the Pope now denies all knowledge of such a map, which --- again, according to him --- is evidence that they have it, but won't admit it.

His name is Reinhard Kristensen (sp?), and he is known, among other things, for having described three new phyla of animals: the Cycliophora, the Micrognathozoa, and the Loricifera (2). Still, he is able to recite in quite a lot of detail the proposed evidence for a Viking dynasty ruling the Incas and mapping all the West Coast of the Americas. I guess this just goes to show that regardless of how well studied you are in one subject, and regardless of how highly thought of you are by your peers, you can still hold ridiculous beliefs in an unrelated field.

---
(1) Unless I misremember, we actually had that dinner when the rocket was launched, but I may be mistaken.
(2) http://icb.oxfordjournals.org/cgi/content/full/42/3/641 is an introduction to all three phyla. I don't know what amount of information is available to non-subscribers, though, as I am logged in through my university at the moment.
ETA: I notice it says "Free" next to the PDF download link, so I assume anyone who is interested could get hold of the article, should they want to.