Science

[Grey_Wolf]

Thanks, Eärniel, for your informative answer.

[Nerdanel]

"Our gut contains trillions of bacteria, known collectively as the microbiome. Their cells outnumber our own by ten to one. We are, to the closest approximation, thriving communities of bacteria encased in a human shell."

isn't that awesome? we call ourself human, and think of ourselves as individuals. still, when we actually look at it, less than 10% of our cells are 'human' and those over 90% that make up the rest of our bodies (and that we couldn't live without) are remarkably similar in most humans. they usually fall into 3 main groups. we also have 100 times more bacterial genes in our bodies than human genes.

combined with the fact that only 1.5% of our genome consists of genes and up to 9% of it consists of viral DNA, you can really start asking how to define a human, how to think of an individual (are we even individuals? are we communities?) and over all, what is a species?

i love biology.



more about human gut bacteria: http://tinyurl.com/6k78jkq
more about viral DNA in our genomes: http://tinyurl.com/6j652lf

[The Gaffer]

IIRC there is a lot of research going on into improving photosynthesis, which is a very inefficient reaction. However there are many limitations. And in the end, they are talking about improving crop yields, not metabolising the atmosphere.

Not so say there wouldn't be benefits: increase crop yields might reduce pressure on existing carbon sinks like rainforests etc.

Agree 100% Nerdy, all that stuff is amazing. Not mention Mitochondrial DNA, an even more intimate union between us and bacteria.

[Gwaimir Windgem]

Just dropping in to note how amusing it is that we have a thread for "Science."

Well, that's nice and specific . . .

[GrayMouser]

Originally Posted by Nerdanel

"Our gut contains trillions of bacteria, known collectively as the microbiome. Their cells outnumber our own by ten to one. We are, to the closest approximation, thriving communities of bacteria encased in a human shell."
i love biology.

Yeah, I remember after spending ten months in India and Nepal I came out with a case of dysentery so bad that the doctor in Australia gave me some kind of medicine as a last resort which was a kind of gut bomb that nuked everything in my stomach- sort of "we had to destroy the village in order to save it".

Then I had to go on a course of treatment to rebuild my internal ecosystem. One little bottle had the label "contains a minimum of two billion living organisms".

[Nerdanel]

Originally Posted by GrayMouser

Yeah, I remember after spending ten months in India and Nepal I came out with a case of dysentery so bad that the doctor in Australia gave me some kind of medicine as a last resort which was a kind of gut bomb that nuked everything in my stomach- sort of "we had to destroy the village in order to save it".

Then I had to go on a course of treatment to rebuild my internal ecosystem. One little bottle had the label "contains a minimum of two billion living organisms".

ouch. >.< i guess that's one way of really getting to know the bacteria in your body...

but you completely recovered from that? how long did you have to take in bacteria for?

[Jonathan]

Antibiotics and probiotics. Youghurt (lotsa good bacteria) is supposedly good for your gut after an intensive antibiotics treatment.

[GrayMouser]

Originally Posted by Nerdanel

ouch. >.< i guess that's one way of really getting to know the bacteria in your body...

but you completely recovered from that? how long did you have to take in bacteria for?

It was a long time ago, but IIRC only a couple of months- huge dietary restrictions at the time, though.

[GrayMouser]

Originally Posted by Gwaimir Windgem

Just dropping in to note how amusing it is that we have a thread for "Science."

Well, that's nice and specific . . .

I dunno- if you go to some science sites, they may have a thread for 'literature' or even "non-science topics".

[The Gaffer]

@ GM: ouch.

University Challenge has one category for science and about a million for each Greek play. Bloody toffs.

[Rían]

Originally Posted by Nerdanel

"Our gut contains trillions of bacteria, known collectively as the microbiome. Their cells outnumber our own by ten to one. We are, to the closest approximation, thriving communities of bacteria encased in a human shell."

Kinda sounds like the upcoming Dr. Who episode!

[Nerdanel]

Originally Posted by RÃ*an

Kinda sounds like the upcoming Dr. Who episode!

XD indeed! i wonder what the doctor's microbiome is like - after all, he's been basically everywhere and everywhen.

[GrayMouser]

Just yesterday came across a bit of info on a subject I'm interested in, which is ther origins of the Austronesian people. Most linguistic research shows this to be Taiwan, but evidence confirming it was recently found by doing DNA comparisons of a stomach bug Helicobacter pylori

The authors collected samples of the bacteria from the stomachs of more than 200 individuals living in Taiwan, New Guinea, Polynesia, and dozens of other Pacific islands. Using techniques similar to those used in human DNA studies, the authors were able to track the different strains of H. pylori back to their common origin: Taiwan, about 5,000 years ago.

But how do these results stack up to findings by other researchers? Interestingly, a companion piece in the same issue of Science also examined the peopling of the Pacific, this time focusing on the linguistic history of the Austronesian peoples. That study analyzed more than 400 languages in the Austronesian linguistic family, using the similarities and differences to figure out when and where the group originated. The results of this study also support an origin of Austronesian peoples in Taiwan about 5,000 years ago. In addition, both studies argue that people expanded in a similar direction: from Taiwan eastward towards Melanesia, Oceania, and finally Polynesia and the Hawaiian Islands.

http://spittoon.23andme.com/2009/01/...f-the-pacific/

[Nerdanel]

no insect has 3 pairs of wings - there are those with 2 pairs, and those with 1 pair. well, that's actually not accurate, because in a recent scientific paper, scientists claim that on group of insects - the treehoppers - have developed 3 pairs of wings. it's just that the first pair doesn't look like wings at all:




yup, those weird-ass structures the insect has on its head are modified wings. they develop from wing genes and are attached to the thorax by muscles, so they can also move them. they can also lose the structure without being badly injured - like insects can lose a wing without dying as a direct consequence. this is in contrast with other magnificent head structures that can't be removed from the insect without killing it:



the genes that are responsible for the body plan in most animals are called hox-genes, and they're extremely conserved. otherwise, we'd end up with legs on our heads and antennae on our thoraxes. the treehoppers have managed to modify genes that do allow for 3 pairs of wings, but have been repressed in all other insects. and the end result has been incredible.




more from:
not exactly rocket science
alphagalileio

[Earniel]

Heh, always fun to find other people who read the same blogs.

I Not Exactly Rocket Science.

[The Gaffer]

Thanks for the link.

Stag beetles rule.

What does "extremely conserved" mean?

[Tessar]

Those are so cool.

Nightmarish, but cool....

[Nerdanel]

Originally Posted by The Gaffer

What does "extremely conserved" mean?

ok, 'extremely' might be a bit much. basically it means that all animals have hox genes that are of the same origin, which in turn means that they appeared very early in the evolution of animals. they're interesting genes in the way that the genes coding for different developmental structures are in the same order as the structures they encode: so for instance the genes for mouth parts, antennae, the head, the forelegs, the thorax, the hindlegs and the abdomen are in that same order on the chromosome (in fruit flies). this is also the case for vertebrates, but of course some of the structures are different.

mutations in hox-genes are quite interesting and quite extreme (which is why they're conserved). they're called homeotic mutations and one of the well known ones is the mutation in the antennapedia-gene, which causes legs to form on the head instead of antennae:



plants also have hox-like genes, but they're not of the same origin as the animal hox-genes.. so yeah, 'extremely' is maybe a bit extreme.

[Nerdanel]

Originally Posted by Tessar

Those are so cool.

Nightmarish, but cool....

hehe.. especially that one with an ant on its back! pretty cool structure to have evolved (and apparently pretty good defence against predators).

[The Gaffer]

Aha, so that's why they call them "conservatives".