Sunday, October 30, 2005

Absinthe

An interesting application of chemistry:

Breaux has made understanding the drink his life's work. He has pored over hundred-year-old texts, few of them in English. He has corresponded with other amateur liquor historians. The more he's learned, the more he's felt compelled to use his knowledge of chemistry to crack the absinthe code, figure out exactly what's in it, puncture the myths surrounding it - and maybe even drink a glass or two.


I've tried the so-called absinthe available from the Czech republic... it really is just green vodka with anise. It doesn't go milky when you add water, and it isn't an appealing taste. I'm curious to try a bottle of the Nouvelle-Orleans, but with a price-tag of 55 pounds a bottle, its a bit on the expensive side. Then again, a bottle of marginal whisky costs about 300 kroner (about 30 pounds) at the vinmonopolet, so maybe its not that bad a deal.

Oikopleura

I just realized that two weeks on, I still haven't said anything about oikopleura besides a general description of urochordates. I'll post something soon, but just to keep people interested, here is a picture of one of the little fellows:


If your wondering about why he looks so funny, its because he's glowing green (unfortunately, the camera was black-and-white only).

And no, they don't normally glow green. Thats where I come in.

Visitors....

I've been stuck at home sick for the last few days, which for me usually means a combination of frustration and boredom, interrupted by bad 50's sci-fi movies (today: Invaders from Mars, original and remake) and flipping through blogs. One of the nice utilities of the site meter is that it takes note of where a person came from when they arrived at my site. A lot of the new visits are thanks to a I and the Bird... I'm not really a bird person, preferring invertebrates, but maybe this might motivate me to post a few of my pics of the Norwegian and Shetland birdlife. We don't get a huge number of bird species up here, but up in the mountains I've seen a few ptarmigan, while the Shetland islands are a good place for gannets, skua, and guillemots.

Some of the referring links don't make much sense... blogspot has a feature that lets you jump randomly to another blog, and I think thats where a few of the hits are coming from. One odd one comes from what I'm guessing is a right wing site that quoted my commentary on Arctic penguins. I'm thinking they missed the point (I don't think they read the original Guardian news story) since their take on it is that global warming is already here, so there is no point trying to do anything about it.... lets just keep partying. I hope for their sake they don't live in a coastal area and that they don't care much for seafood.

I'm going to give a tip of the hat to one reader I came across, at The House and Other Arctic Musings. The Canadian arctic is the one part of that country I never had a chance to visit and I've always wished I had. In my university days, I knew people who did research up in the Arctic, from Tuktoyaktuk to the Queen Elizabeth Islands... including one fellow who worked on the overwintering of the Arctic Woolly Bear caterpillar. Apparently the subject of exactly how many years these caterpillars overwintered was quite contentious, and I remember one very angry blow-up at a conference between the 14-year side and the 8-year side of the question. I guess if you spend that many years watching a caterpillar grow, you take the subject very very seriously.

Friday, October 28, 2005

Random 10

To Die For, "Crimson Twins"
Cradle of Filth, "The Mordant Liquor of Tear"
54-40, "Easy to Love"
Cradle of Filth, "Mother of Abominations"
Rolling Stones, "Paint it Black"
Silke Bischoff, "Love Never Dies"
Cradle of Filth, "Thank God for the Sufferin"
Deathstars, "Synthetic Generation"
MC Hawking, "Gin and Juice"
Mindrot, "Burden"

Its been one of those days....

Thursday, October 27, 2005

Creeping nightmare... of Lewy bodies!

This is truly scary... apparently a new line of thought holds that Parkinsons disease is just the final stages of a progressive brain degeneration that works its way up the brain stem, disrupting functions as it goes. The problem is, since these disruptions cause only minor behavioral and sensory changes, the only way to know for sure that your on the road to Parkinsons is to have your brain sliced up in a hunt for Lewy bodies... clumps of the protein alpha-synuclein in the brain. Not really a practical test, although I'm sure its great fun at your autopsy to see what diseases you were in line for if you hadn't had those three bottles of Norwegian moonshine at the Christmas party.

The worrysome bit is that the 'early' symptoms caused by this gradual brain degeneration include muscle movement during REM sleep. Normally, when you sleep a part of your brain called the pons shuts off all of your muscles except for those of the eyes... people who have damage to the pons 'act out' their dreams, flailing arms and legs around as they run and jump in their dreamworld. Up from the pons is the substantia nigra, the part of the brain that gets damaged in Parkinsons disease and causes loss of muscle control. What they think happens is that first the Lewy bodies show up in the lower brainstem, work their way up through the pons, and then expand into the rest of the brain, including the substantia nigra. Only when it hits the substantia nigra are the symptoms strong enough to get attention, however... by which time Lewy bodies are all over the place.

So now I have to worry about whether I move in my sleep... am I just rolling over, or is this the first sign of a downward spiral? It could be worse though...

Sleep neurologist Brad Boeve recalls one couple who described a particularly horrendous night-time event. While they slept in their bed, the husband suddenly grabbed his wife's head, shook it around roughly, then slammed it down hard and threw up his arms. Far from being intentional, this distressing episode was the result of a disorder that sees sleeping people physically act out their dreams. In this instance, when the husband woke up he revealed that he had been playing rugby in his dream, had scored a try and then raised his arms in victory.

That fellow may not live long enough to get Parkinsons, if his wife has anything to say about it.

Wednesday, October 26, 2005

2000

Its strange to think how two and a half years ago I sat eating lunch in a Kansas sportsbar, watching the first rockets strikes hit Baghdad on the big screen TV and listening to people cheering each explosion, as though celebrating a touchdown by the home team.

I thought then that no good could come of this war, but I don't feel any satisfaction in being proven right.

This Saturday Staff Sgt. George T. Alexander Jr. became the 2000th US casualty of the war. Our allies together have lost over 200 men, and countless tens of thousands of Iraqis have been killed in this disaster. I'd like to think that with Bush's poll numbers crashing we have reached a turning point, but Bush is not a man given to admitting wrong. I can't help thinking there will be far more than 2000 US dead by the time this is all over.

For sale: One childs mind

This is a worrying development:

Private education companies and Christian groups are lining up to enter the education market created by yesterday's pivotal reforms of the state school system.

The moves follow publication of the education white paper unveiling plans to turn all primary and secondary schools into "self governing independent state schools". Every school will be encouraged to acquire a trust, made up of business charities, faith groups, universities or parent and community organisations. The trusts will be able to appoint the governing body, own their own assets, set their own admissions policies as well as control teachers' pay and conditions.


This sounds like a perfect setup for corporate and religious groups to influence (= muck about with) the curriculum. I know the British education system has its problems, but this reeks of some ideological quick fix. Coupled with the rise in American-style fundamentalism and creationism in England, I'm wondering if Blair is taking a page from the Republican playbook and starting to pander openly to the religious right.

Tuesday, October 25, 2005

Go West, Young Blackcap!

Considering that I will soon be 'migrating' to England this winter, it seems fitting to mention another group of migrants who are willing to pass up the warmth and culture of the Spanish Mediterranean for milky tea, warm beer, and Fray Bentos meat pies.

Every year, Blackcaps (Sylvia atricapilla) migrate from their summer breeding grounds in Central Europe to wintering grounds in southern Spain and Portugal. Over the past 40 years, a subpopulation of these birds has decided to go west instead, wintering in the much less pleasant British Isles. Since migration routes are genetically determined, this is a fairly radical change of direction which has raised numerous questions. Scientists want to know both why some of the birds are heading westwards (there must be some selective benefit, or this trait would die out of the population) and how can two genetically different populations maintain their distinctiveness if they breed in the same location?

The problem scientists encounter in studying this question is how to determine which birds came from where. These birds are too small for radio collars, and there are too many for mark and recapture studies. The genetic differences between the England winterers and the Spain winterers is probably extremely tiny, since the genetic change that led some to migrate west only turned up 40 years ago. This prevents any simple DNA tests to determine where the birds came from.

In a recent Science paper, Bearhop et al. make use of an original method to figure out where they birds come from... they measure the stable hydrogen isotope ratios in the birds tissues. The amount of deuterium (hydrogen with a neutron attached) to regular hydrogen (no neutron) in a bird is determined by the rainfall in the birds environment. Since England and Spain have very different rainfall profiles, Bearhop et al. were able to take small samples from birds as they arrived in Central Europe to breed and use the ratios to figure out whether the birds were Spanish or English.

What they found was that British birds arrived in Central Europe earlier than Spanish birds. When these birds went looking for partners, all they would find would be other Brits. By the time the Spanish birds arrived most of the English birds were already partnered up and the Spanish birds would naturally have Spanish partners.

The mechanism for this difference in arrival times is a very simple one... the birds use day length to tell them when to head for the breeding grounds. At northern lattitudes, the critical day length is reached earlier than at the more southerly lattitudes, causing the British birds to pack off to Europe 10 days earlier. The end result is two populations of birds breeding in the same location at more-or-less the same time but only breeding with their fellow countrymen despite the presence of other potential partners (a process called assortative mating).

So why go to England anyway? One obvious advantage is that by returning to Central Europe earlier, the British birds get first claim on breeding territories. Other possible advantages are the shorter distance that British birds have to fly, while the increase in backyard bird feeders in England may be aiding Blackcaps through the winter.

It will be interesting to know what happens to this population in the long run.... are we watching speciation in action, with the Blackcaps splitting into a British species and a Spanish species? Or are we seeing a selective sweep.... the eventual replacement of Spanish migrating Blackcaps with English migrating Blackcaps?

This will be one bird I'll be keeping my eye on when I have my own 'winter migration'.

Sunday, October 23, 2005

Shake hands with the Devil

In 1994, the world stood by and watched while all hell was let loose in a small African country called Rwanda. When a rocket destroyed the airplane of Rwandas President Habyarimana, the brutul Interahamwe militia backed by the the Rwandan military unleashed their guns and machetes on the Tutsi population... killing men, women, children, stranger and neighbor alike.

In the middle of that barbaric massacre, desperately trying to bring order and save lives, stood Lt. General Romeo Dallaire and a small force of 300 Tunisian, Ghanian, and Bangladeshi soldiers. Overwhelmed, outnumbered and abandoned by the UN, they fought on to save as many lives as they could. Their actions are credited with saving the lives of 20,000 Tutsis and Hutu moderates... a feat in itself, although but a shadow of the 800,000 people murdered during those 100 days.

Shake Hands with the Devil documents Gen. Dallaires return to Rwanda 10 years later. One of the most powerful movies I've seen in a long time, this movie relives through the generals memories the bloody events that engulfed Rwanda, and how the country is still coming to terms with the genocide. As Romeo describes the events of those horrible days, we are taken from the bustling streets of Kigali in the present day to those same streets 10 years ago... piled with corpses and patrolled by the machete-weilding death squads. We see a man still racked with guilt for a massacre he could do nothing to prevent, despite heroic efforts against impossible odds.

The movie pulls no punches. We see the grandstanding Belgian senator Alain Destexhe accuse Dallaire of complicity in the death of 10 Belgian soldiers, saying in effect that the general should have risked his entire force to save 10 European whites, nevermind the 800,000 black Africans dying all around them. We hear how the the Catholic Church stood by as Hutu extremists used the pulpit to spread hate against the Tutsis. We learn of how the French government aided and armed the Rwandan military and the Interahamwe militia (to this day, leaders of the Interahamwe live in luxury in France). Ultimately, we see a country descending into flames and the outside world at best, turning away... at worst, feeding the fire.

And in the middle of it all, one man trying to do what was right.

Conservatives eat their young...

...at least, that was my first impression when I read this:

While the recent nomination of Hariet Miers for the Supreme Court by George W. Bush may have revealed more than a few cracks in the usually lockstepped Conservative Movement in America, Daniel Borchers has been calling out "fake Conservativism"

...

Borchers' organization, Citizens for Principled Conservatism (CPC) is currently in-production of a documentary named The Truth About Ann which aims squarely at political and religious hypocrisy of Rightwing commentator and author, Ann Coulter.


I don't have a lot of regard for the Christian Right, and none at all for Ann Coulter, but I've lived in the midwest long enough to know that somewhere obscured by the self-serving pundits, hate-spewing preachers, and their extremist supporters there are decent conservative Christians who do not stand with the hate and the hypocracy that has engulfed the conservative side of politics.

There is much more at bradblog... its worth a look to see how Ann Coulter is beginning to alienate her base. Hopefully, obscurity beckons.

Friday, October 21, 2005

Anomalocaris

Pharyngula has a slightly different take on the same article.... focusing more on the tagmosis side of things (appendage homology based on which segment they emerge from). Tagmosis is a bit of a nightmare though... the farther back from the head you go, the more the appendages diverge into different specializations among different arthropod lineages, and the less sure you are about homology. Molecular work on developmental genes is going a long way towards sorting this out (thats how we know that the chelicerae in spiders is innervated from the deutocerebrum rather than the tritocerebrum), but for me its less interesting to argue over whether a pincer in one lineage is homologous to a paddle in another than to examine how both derived from an ancestral precursor.

That said, the more I think about linking the chelifores of sea spiders to the 'great appendages' of Anomalocaris, the more uneasy I get that we are leaping well ahead of the data. The big problem with the Cambrian lagerstatten is that they are snapshots in time... you don't get much in front of them and even less behind as they formed under fairly rare conditions. Anomalocaris appears then disappears, and its next to impossible to link it to any previous ancestor or descendant species. Although a few interesting lagerstatten fossils have shown internal anatomy, thats pretty rare, and usually confined to digestive systems. We don't have any idea how the neuroanatomy of Anomalocaris is arranged, and barring some miracle we find them swimming about a deep sea trench, we never will. The problem we have with Anomalocaris (and with other Cambrian arthropod-like fossils) is the same problem we have with contemporary arthropods... uncertainty about which segment is truly homologous with which, and (until recently) only the appendages to give a clue as to identity. What work like that of Maxmen et al. have done is show that appendage identity is really not that reliable a marker for segment homology. Unfortunately, studies such as hers are impossible on 500 million year old fossils.

Comments back up again

Looks like haloscan was having a bad day.

Comments look down

Wonderful... haloscan doesn't appear to be working this morning.

Thursday, October 20, 2005

Getting a head in the world...

The power of segmentation has always fascinated me. Starting with some generic animal where every segment is identical, you can evolve a myriad assortment of specializations: segments with legs, with wings, with cutting jaws, with specialized hairs for digging, with paddles for swimming, flaps for moving water through a burrow, tentacles for filter feeding.... the possibilities are tremendous. The diversity that can emerge from a simple body plan through specialization of segments can be seen all around us - from centipedes and spiders to giant Atlas moths, dragonflies, lobsters and barnacles.


One of the side effects of segmentation in arthropods is their decentralized nervous system. Each segment has its own mini-brain – a cluster of neurons organized into a mass called a ganglion – that takes care of local tasks such as moving that segments appendages and collecting information from that segments sensory neurons. The arth
ropods actual brain is more of a coordinator… it tells the segment what to do, but leaves it up to that segment to handle how to do it. That’s why when you remove the head of a cockroach, the body can scuttle away in one direction while the head flops about in the other.

Interestingly, the brain of arthropods started out as a set of segmental ganglia like those found in other segments. While most segmental ganglia specialized to coordinate movement, the ganglia of the first three segments of the ancestral arthropod developed around collecting and processing sensory information, and coordinating activity for the other body segments. Even though arthropods no longer have obvious head segmentation, we can see remnants of this ancestral segmentation by looking at what appendages are directly controlled by the brain.

The arthropod brain consists of three parts – the protocerebrum at the front, deutocerebrum in the middle, and the tritocerebrum at the rear. In insects, the deutocerebrum supplies nerves to the antenna while the tritocerebrum sends nerves into the labrum (a plate in front of the mouth that helps hold food in during chewing). In crustaceans, the deutocerebrum and tritocerebrum feed nerves into the primary and secondary antenna respectively. In spiders, it is the deutocerebrum that handles the head appendages (in this case, the chelicerae – the ‘fangs’ of the spider).

The big question has always been where did the protocerebrum come from? Unlike the other brain segments, there are no appendages associated with the protocerebrum – instead, it sends nerves into the eyes. This has led some people to think that the protocerebrum is a special structure originating from a hypothetical anterior region called an acron that never had appendages.

However, a recent paper in Nature describes how an obscure group of arthropods known as sea spiders or pycnogonids uses its protocerebrum to control its feeding arms (known as chelifores). These animals start out almost as little body-less heads… they have only a set of chelifores and two pairs of legs, innervated by the proto, deuto, and tritocerebral ganglion respectively. As they get older, they metamorphose into a creature that resembles a very thin spider, with 4 to 6 pairs of true legs. The head retains the chelifores and the larval legs are modified into feeding appendages (palps).

a, The three appendages of the protonymphon larva (shown) correspond to the cephalic appendages of the adult pycnogonid. b, The adult male cares for embryos until hatching (Nymphon rubrum).

Neuroanatomy of sea spiders implies an appendicular origin of the protocerebral segment
Amy Maxmen, William E. Browne, Mark Q. Martindale and Gonzalo Giribet
Nature 437, 1144-1148 (20 October 2005)

While insights into the brains of arthropods are interesting in their own right, whats fascinating about these findings is that we may be getting a glimpse into the ancestral arthropod ground plan. An accumulating body of evidence suggests that sea spiders represent the earliest branch of the arthropod lineage, before it diverged into insects, spiders, and crustaceans. While sea spiders are clearly specialized and have a fossil record that only goes back to the Devonian, the presence of appendages at the very anterior of the animal is tantalizingly similar to structures found on several Cambrian fossil animals such as Anomalocaris.

Its possible that the ancestral arthropods started life much as sea spiders do – as a body-less ‘head’ with a pair of anterior feeding appendages and two pairs of legs, and that as they grew they added additional leg bearing segments. Over the course of evolution, the legs (both the original two pairs and those occurring on later segments) specialized, with the anterior legs becoming additional feeding appendages and the posterior legs devoted entirely to walking. Finally, a point was reached where the appendages of the first segment were no longer needed and they were lost in the ancestor to most modern arthropods… except for the sea spiders, which had already diverged. During the course of these events, the original three ganglia expanded their function form simply moving the appendages to coordinating the sensory input and behavior of the entire animal.

Of course, this last bit is speculation… the Cambrian fossils have left no trace of their nervous systems and little is known about the larval stages of most Cambrian animals…. but if correct, it would go a long way to explaining how simple segmentation led to the most diverse group of animals on this planet.

Back away slowly....

From Krauthammer at the Washington Post:

Beyond the brilliance lies the sheer terror. We have brought back to life an agent of near-biblical destruction. It killed more people in six months than were killed in the four years of World War I. It killed more humans than any other disease of similar duration in the history of the world...

...resurrection of the virus and publication of its structure open the gates of hell. Anybody, bad guys included, can now create it....

Why try to steal loose nukes in Russia? A nuke can only destroy a city. The flu virus, properly evolved, is potentially a destroyer of civilizations.

We might have just given it to our enemies.

Ooookaaaayyyy..... Someone needs a dose of reality. This is the sort of bad writing on science that is fueling the current panic over Avian flu. Sure, there are dangers involved in influenza research, particularly with the recreation of the 1918 Spanish Flu strain, and yes Avian Flu has the potential (albiet small) to adapt to human-to-human transmission and become a major threat. However, the last thing we need is crazy doomsday scenarios being touted as established fact and an already jittery public whipped up into a frenzy.

To begin with, we have had the ability to recreate influenza strains for some time now... almost a decade in fact. Since the influenza genome consists of 8 small stretches of RNA, its not hard to translate the RNA into a more stable DNA molecule and 'store' each stretch as a plasmid... a circular loop of DNA with extra sequences that allow it to grow and be maintained within bacteria. If you want to reconstitute your flu, all you need to do is put all 8 stretches of RNA into a cell (well, its not THAT easy, but definately not new technology). The real innovation in the recreation of the Spanish Flu was recovering the original RNA from samples preserved or frozen for almost 90 years.

That said, we are a far cry from Osama bin Laden cooking up fresh flu in some cave in Pakistan. You need a fair amount of specialized equipment and know how to do this... not easily accessable to terrorists. Sure, the sequence is published online, but despite what Krauthammer thinks, companies that make DNA do not just sell it to anyone who asks. Trying to remake Spanish Flu by stitching together several thousand tiny bits of DNA is going to require an incredible amount of patience and will definately catch the attention of the authorities.

What frustrates me is Krauthammers conflation of Spanish Flu and Avian Flu... these are two very different flu strains, and the fact both originated in birds is meaningless. What is important is that Avian Flu is a new virus with a high mortality rate, but a very low level of transmission in humans. Its not adapted to us, and with as a high a mortality rate as it has, its unlikely it will get the chance. Spanish Flu, on the other hand, is a product of the unique environment of the first world war. Unlike Avian Flu, it actually got worse as time went on.... adapting to an environment of crowded conditions and poor health, where a highly virulent pathology meant greater success at spreading, rather than being trapped in a dying, isolated host.

Wednesday, October 19, 2005

Or is it?

If there is one hope for the Antarctic organisms threatened by rising ocean tempertures, its phenotypic plasticity.... the ability to be flexible in response to environmental change.

When we usually think of populations of organisms responding to a change in the environment (rising temperatures, new or better predators, new diseases) we often think in terms of genetic changes. In most populations of animals, there is usually genetic variation for any given trait (phenotype)... for example, some animals will be genetically programmed to have taller necks, or more body fat (better able to withstand lower temperatures), or brighter coloration. If the environment changes, some genetic variants within the population will be favored and produce more offspring, while others will die out or fail to reproduce. The end result is that when the population is viewed as a whole, both the the trait in question and the underlying genetics can be seen to change over time... natural selection and evolution at work.

Phenotypic plasticity is the ability to alter ones traits (neck size, fat layer, coloration, etc.) without undergoing a genetic change. The plant or animal may sprout spines in response to predators, change color to better blend in to the background, or produce more offspring when food is abundant.... without changes in the underlying genes. Whats interesting is that this ability to respond to the environment is genetic. When environmental conditions change rapidly, an organism that can alter its traits will do better than one that takes a gamble on its genes and either lives or dies as a result.

I mentioned in my last post how global warming is like a giant man-made experiment in adaptation... well, one of the ways plants and animals are adapting to the rapid changes in climate is to evolve the ability to adapt. In this weeks Science there is an article on how climate change is causing Great Tits (Parus major) to become more flexible as to when they lay their eggs. Great Tits, like most passerine birds, feed their young on caterpillars. In order to ensure their young will have an ample food supply, they try to time the laying of their eggs so that when the eggs hatch, the number of caterpillars available to feed them will be at its peak. Because the growth rate of caterpillars is directly affected by the climate, if the birds want to get the most caterpillars for their chicks they have to breed earlier in warm years than they do in cold years. With recent changes in climate, the Great Tits have been getting more and more out of sync with the caterpillars they depend on, as the caterpillars now peak two weeks earlier, around when the Tits are laying their eggs - not when they are hatching.

What Nussey et al. have found in their review of 30 years of Dutch bird data is the emergence of a sub-population of Great Tits that has become much more flexible in its response to rising temperature and caterpillar emergence. While the Great Tit population as a whole is in decline, these adaptable birds are managing to hold their own and produce more offspring than their less adaptable peers. Its still early in this 'grand experiment', but the outcome looks like these birds that have evolved flexibility will take over and replace their more 'conservative' bretheren. The next big question is whether these birds can evolve enough flexibility to survive as the pace of climate change increases.

Last chance to see.... penguins?

Depressing news from the Antarctic... ocean temperatures are rising much faster than expected, with potentially devastating effects on the marine wildlife.

Animals that live on the seabed around the Antarctic Peninsula, where summertime water temperatures currently peak at about 0.5C, are sensitive to small shifts in temperature. In water just two degrees warmer, molluscs become unable to bury themselves in seabed sediment, limpets cannot turn over and scallops lose the ability to swim. These changes would make them more susceptible to predators, disrupting the food chain and quickly endangering larger animals and birds. "If the warming goes on at the same rate for 50 years or 100 years then lots of populations of animals I work on, and maybe entire species, would be at risk," Professor Peck said.

This doesn't really surprise me.... the arctic and antarctic regions of this planet have been seeing some of the strongest effects of global warming, with average air temperatures rising and glaciers showing signficant melt. It only makes sense that the warming would affect the ocean water itself. Unfortunately, these effects are not going to limit themselves to just the polar extremes.... its tempting for some to think that we are just going to lose a few obscure animals in a place that no one ever visits, so who is going to care? However, the Antarctic and Arctic oceans are important food resources for birds and mammals (particularly whales) that migrate there to feed before returning to more temperate water. Extinctions at the extremes of the globe will have effects that reach far into our own familiar territory.

The worst part is that there isn't much we can do about it now... we've passed a point of no return in global warming. Not much to do now but enjoy the worlds largest experiment in organismal adaptability.

Journalism and Science

Once upon a time I thought of being a science journalist instead of a scientist.... this blog is in some ways an attempt to try and write about science for a general audience. I've always felt that it is important for scientists to convey to the 'ordinary Joe' what it is they do, not the least because the 'ordinary Joes' of the world pay our salaries.

So why did I major in Biology instead of Journalism? Well, for a start, attitudes like this one:

A problem exists within the high-school education system: It doesn't prepare students for their careers. When I decided in high school that my major was going to be journalism, I took the only class offered by my school in hopes of learning the journalistic writing style. I didn't learn anything from that class. My teacher was not a journalism teacher; she was an English teacher. We spent every class silent reading instead of learning about the inverted pyramid.

The school system needs a reality check; most students aren't going to be mathematicians, historians, or chemists. So why do we have to take these classes
This from a journalism major. Worse, this was printed in a school paper, with the approval of various collegues and editors... also (I would guess) journalism majors and professors.

PZ Meyers and SuperDoomedPlanet have already had a take on it, so I'm not going to say more about our budding young journalist from Iowa. Her attitude doesn't surprise me though... I've written for several university papers, and one thing that has struck me is how journalists are encouraged to be empty vessels that merely regurgitate whatever is fed to them. This makes the average journalist fresh from J-school a terrible science reporter, since they lack any background at all to understand what scientists are telling them, never mind to evaluate what they are saying. What I've always found ironic is that the one area of journalism where this emty-vessel attitude is not encouraged is sports journalism. Would a newspaper hire a sports journalist who thought Knute Rockne was the British ski jumping champion? Why then do they discourage thinking skills in other forms of journalists?

Journalism shouldn't be a major at all, but rather a set of courses that focus on the specialized style of writing and information gathering journalists need, taught alongside a major in some other field... science, english, psychology, philosophy... something that broadens the future journalists horizons so that they can understand, evaluate, and ultimately select the information given to them for inclusion into their articles. Journalists need to be intelligent, well rounded individuals. Not empty echo chambers like our aspiring journalism major from Iowa.

Adding a site counter

Perverse curiosity if anyone is actually reading any of this...

Urochordates

Well, now that the introduction is out of the way, time to bring out the first (of I hope, many) creatures I'll be highlighting on this blog. And what better organism to start with than the one dear to my heart, Oikopleura dioica? But first, I need to throw in a bit of general background on the larger group of organisms to which Oikopleura belongs.... the urochordates.

So what is a urochordate? Probably the most familiar member of this group is the sea squirt... a marine animal that sits attached to rocks, spending its life sucking in water through one hole, filtering out the food with a big bag of mucus, and then sending the waste water out another hole. Sea squirts lead a sedentary existance, quietly filtering away until old age or predators get them. However, for a very brief period in their life sea squirts can be very active. Newly hatched sea squirts come out of the egg looking like little tadpoles... a lump of a body with a tail attached to the rear. They swim about for several hours looking for a solid surface to land on, then glue their heads to ground, absorb their tails, and metamorphosize into a sac-like creature with an intake and an outflow hole.

Its that tail that makes sea squirt larva so interesting... it has several features that indicate urochordates branched off early from the same evolutionary line that led to us. Running down the center of a sea squirts tail is a rod-like structure known as a notochord, which gives support to the tail and helps provide something for the muscles to act upon. Running the length of the tail just above the notochord is the dorsal nerve cord, transmitting signals from the sea squirts brain to the tail muscles.

If this sounds a bit familiar, its because we have a similar system in our bodies... a dorsal set of vertebrae to which our skeleton and muscles are attached and a dorsal nerve cord running above the main axis of the vertebral column (although also surrounded and protected by vertebrae). Early in our development, we also have a notochord, but as we grow it becomes replaced by our bony vertebrae. The reason for this replacement is obvious... what can provide structural support for a 2mm long aquatic larva would barely hold together a 6 foot tall terrestrial biped. In fact, only two other groups retain their notochords... the lancelet fishes (not an actual fish, but similar in appearance) and the hagfish. In all other chordates, the notochord is replaced by either bone or cartilage.

Although all urochrodates have a notochord, a dorsal nerve chord, and thrive by filter feeding plankton through a mucus bag, not all have become sedentary animals like the sea squirts. Oikopleura belongs to a group of urochordates called the Appendicularians.... these fellows hatch out of the egg looking like sea squirt tadpoles, but instead of attaching to a rock and losing their tails, they keep their tails into adulthood. Whats unusual about the Appendicularians is that to help themselves get food out of the surrounding water, they build for themselves houses of protein and cellulose that contain an elaborate system of filters to concentrate the food, remove stuff they can't eat, and bring the rest into their mouths. The beating motion of their tails powers this massive food concentrator, drawing in the food laden water to the filters.

I'll have more to say about the Appendicularia in my next post... hopefully with some pictures included.

Tuesday, October 18, 2005

Year 0

Welcome to yet another blog cluttering the pages of the internet.... though hopefully this will be a blog with a difference.

The aim of this blog is to talk about my favorite subject, the biology of obscure organisms.... all of those little creatures that rate only a paragraph or two in the back pages of dusty tomes, or which occupy a single slide on the neglected shelves of museum collections. You might remember them from some college lecture... mentioned briefly then forgotten. Something jelly-like, or with legs sprouting in all directions, or tendrils creeping through some other creatures body. The strange plants and animals that made you sit up in biology class and think 'that is really weird'.....

Of course, I'll be posting on other subjects as well.... mostly science related with a few scattered rants, though I want to avoid this becoming a political blog. Hopefully every week or two I'll be able to profile an obscure organism... something newly discovered, or more likely, almost forgotten.
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