Saturday, September 03, 2005

Chimp genes, reverse laterality, Ichthyostega, outhouses, and more!

` Quite unremarkably, I've been been in Everett for a whole year now! I, Phil, and my mom ironically marked this occasion with a hike up Sunrise Pass. EdgeWalker didn't go due to sleep deprivation, though he made pizzas, which we all participated in eating.

` So what's in my Inbox on this day? Let's see... lotsa neat things! Have a scroll!
` (I happened to find a fun little thing near the end!)

` The chimp genome has finally been sequenced, and the edition of Nature that this appears in is free! Chimps share 98% of our general DNA (both coding and non-coding), and almost all of our genes.
` There's a bunch of little films to watch showing the cognitive abilities of chimps... unfortunately, trying to open them causes Foxfire to crash. Bizarre!

` Oh well, there's always this description of the papers about chimps:

The paper describes changes that have shaped human and chimpanzee species since the split from our common ancestor, and hints at what makes us uniquely human: 35 million single-nucleotide substitutions, 5 million small insertions and deletions, local rearrangements and a chromosome fusion....

The final research paper in this collection fills a big gap in our knowledge: the first chimpanzee fossils ever found show that chimps and early humans inhabited the same environments in which they evolved and diverged. The fossils — three teeth — are from half-million-year-old sediments in Kenya that also yielded fossils of Homo.

` Neat! Then, there's this weird-sounding bit of gunk I will explain:

Laterality of the nervous system is intimately associated with asymmetry of the viscera, a fact that is highlighted by the reversals of some brain structures in people with situs inversus totalis, in which the positioning of internal organs is inverted. But individuals with this condition retain left-sided language processing, which indicates that functional laterality of the nervous system does not always follow asymmetry of the viscera.
` In other words, when people's internal organs (viscera) are 'backwards' (i.e., the liver is on the left while the heart is on the right, etc), their brains are also mostly this way - though not completely: The language processing center, for instance, stays on the left side.
` The article is basically about how left-right reversals (in zebra fish, sea urchins etc.) is controlled by a very complex bunch of genes that nobody really understands that well.


` Oh hey, neat! They found that the hipocampus is active when you're asked to find the best route between friends' houses - However, it isn't when you're trying to find an optimal route between friends (using social connections instead of places as navigational markers).

The two behaviourally matched tasks elicited distinctly different patterns of fMRI activation. Importantly, the hippocampus was active in response to the spatial, but not the non-spatial, relational processing task — findings that are consistent with the cognitive map theory of hippocampal operations.
` The cognitive theory says that you should find that the hippocampus is not active when you're remembering maps between places. The relational theory basically states that the hippocampus is involved in not only spatial tasks, but other forms of relational-type things.
` Since the hippocampus only seems to be involved in spatial tasks, it looks like the cognitive theory makes the most sense.


` Ooh! There's a bunch of stuff in
Nature'sMicrobiology Reviews about horizontal gene transfer. What's that? I'm not exactly sure... I've heard that this is the swapping of genes from one prokaryote to another, and when this spreads helpful mutations around, it can mean the difference between life and death.
` Wish I knew more, but I don't have time to read up on it. I think viruses are the mediators. They'd have to be, anyway, wouldn't they? Rrrgh.
` From what I can gather, the articles are about such things as how we should structure the prokaryotic family 'tree'. These most primitive microbes not only evolve in a treelike fashion, they have plenty of genes that will go horizontally across 'branches'. This makes the 'fuzziness' between the genetics of similar eukaryotic subspecies (such as various species of newts or dandelions) downright smooth!
` I think that's neat. Most genes (in say, a bacterium) are inherited, but to shake variability up, many genes spontaneously mutate into different forms, and some are even imported from completely different lineages, for better or for worse.


` Hey, lookee! Early land-fishies! With more specimens of
Ichthyostega at hand, we can now have a more detailed look at the primitive, four-legged lungfish-like animal:
` It differs radically from previous versions in having a regionalized vertebral column that bears a striking resemblance to that of a mammal. The presacral vertebral column appears to have almost no lateral flexibility, but there is vertical flexibility in the lumbar region.
` This suggests that Ichthyostega could move on land using a bilaterally symmetrical 'shuffling' action. It may have been an early and ultimately unsuccessful attempt at adapting the tetrapod body plan of terrestrial locomotion, a problem solved by a tetrapod lineage quite closely related to Ichthyostega.

` And now, a bit of classic
Straight Dope:
Dear Cecil:

Why do outhouses have half-moons on their doors? Perhaps it's related to the great high school custom of "mooning"? --Joyce K., Seattle


Cecil replies:

This is no time for buffoonery, Joyce.

Level with me: you've never actually seen an outhouse with a half-moon cut into the door, have you? Neither have I, despite several decades of camping trips. I'll bet the same goes for just about everybody else.
` The idea that outhouses always have moons on them has been perpetuated largely by several generations of cartoonists (e.g., Al Capp), probably none of whom ever saw one either.

The only reference I can find to the practice is in Eric Sloane's The Little Red Schoolhouse: A Sketchbook of Early American Education. Discussing 18th- and 19th-century schoolhouses, Eric writes:
` "The woodshed was often a lean-to attached to the schoolhouse, but the most accepted arrangement was to place it between the schoolhouse and the privy, with a fence separating the boys' entrance from the girls'. The ancient designation of privy doors was to saw into them a sun (for boys' toilet) and a moon (for girls' toilet)." Eric has supplied a sketch of both versions, showing the familiar crescent moon for the girls and a radiant sun for the boys.

By way of corroboration, I note here in my manual of semiotics that the moon "is usually represented as the feminine power, the Mother Goddess, Queen of Heaven, with the sun as the masculine." Isn't that just great? All this time you thought you were in there just doing your business and now it turns out you were participating in a pagan ritual.

Why cartoonists picked up on the moon rather than the sun as the universal symbol for outhouse is hard to say. But knowing cartoonists I'd guess it has something to do with the fact that the radiant sun is hell to draw. The reason there's a hole in the first place is a lot simpler: it provides ventilation.
` But then, someone else writes to argue about it, and he finds, in The Vanishing American Outhouse, a more elaborate explanation.
"Luna, the ancient crescent shaped figure, was a universal symbol for womankind. A moon, sawed into a privy door, served as the 'Ladies Room' sign of early innkeeping days. Sol, a sunburst pattern, was cut into the men's room side of the outhouse. These symbols were necessary because in Colonial times only a fraction of our population could read or write.

"As time passed by and frontiers were pushed further westward, the gentlemen's restrooms fell into disrepair and eventually were abandoned altogether. Accommodations for ladies were better maintained and this is why the moon symbol remains on many outhouse doors today. Its original meaning, however, was lost to the general population sometime in the mid 1800's."
` Ooo-kay... If that's true, then I wonder why the men's rooms were, over time, taken for a lost cause? Maybe they just weren't as important? I wonder if the men just started using the ladies' rooms then?
` Hmm.


` My last piece of mail worth note is this
eSkeptic article about how this Dr. Krukoff guy blew this prayer experiment way out of proportion:
In news interviews following its publication, Dr. Krucoff claimed he and his co-authors saw “impressive reductions in all negative outcomes” — including congestive heart failure and death — among patients who received remote prayer treatment, compared with those who were not treated with prayer.

“If one takes the trouble to read the MANTRA I study,” says Skolnick, “ one can see that the prayed-for group of patients had one more death than the patients in the group who received only standard care. Contrary to what Dr. Krucoff told the news media, there was no difference, impressive or otherwise, in the number of patients who suffered congestive heart failure.”

In the pilot study, 30 patients undergoing conventional therapy to unblock their coronary arteries unknowingly received prayers from people they did not know. A variety of clinical results from these patients were then compared with those of 30 patients who received conventional care, but no prayer therapy.
` While no patient in the conventional care group died, one patient in the prayed-for group died during the six-month study period. In addition, no patient in either group suffered congestive heart failure.

Nevertheless, in an interview for the Discovery Channel, Dr. Krucoff states:

We saw impressive reductions in all of the negative outcomes — the bad outcomes that were measured in the study. What we look for routinely in cardiology trials are outcomes such as death, a heart attack, or the lungs filling with water — what we call congestive heart failure — in patients who are treated in the course of these problems. In the group randomly assigned to prayer therapy, there was a 50 percent reduction in all complications and a 100 percent reduction in major complications....

The Lancet study included many more patients than the MANTRA I study and involved eight medical centers in addition to the Duke University Medical Center. It concludes that prayer therapy had no detectable effect on the health outcomes measured in the study. While Skolnick says he hopes these results will finally correct the misinformation about the earlier study that continues to circulate, he fears they may be spun to support the claim that intercessory prayer is effective medical therapy.
` Yeah, it's not like that kind of thing hasn't happened before...

` Anyway, that's all I have for now. Tune in next time...

5 comments:

ChrisWoznitza said...

I hope you had fun and the pizza was delishes

S E E Quine said...

Thanks ;)

Galtron said...

Wow... Pagan outhouses. Deep, man!

Galtron said...

Do the Ichthyostega shuffle!

S E E Quine said...

` Hee hee! Hey, neat Ichthyostega page!