31 January 2007

Tentacle 15

Issue No. 15 of Tentacle, the newsletter of the IUCN/Species Survival Commission, Mollusc Specialist Group is now available (pdf).

This issue features short notes about the native and introduced land snails in the U.S., Romania, China as well as marine and freshwater mollusks. In line with the purpose of the newsletter, all articles have a conservation angle. I have a short note (p. 14) on the interaction of the native U.S. slug Philomycus carolinianus with the introduced Arion subfuscus.

Tentacle, edited by Robert Cowie of the University of Hawaii, comes out once a year, usually in January and it is now distributed almost exclusively over the Internet. It's been in color since 2006. All past issues of Tentacle are available here.

Boxcar graffiti XLI & XLII



30 January 2007

Bioturbation all around you

This little freshwater snail, probably a Helisoma sp., created a record of its movement in the fine sediment layer covering the rocks on the bottom of a shallow pool next to a creek.

Bioturbation is the disturbing and mixing of soils and sediments by organisms that live or feed in them or simply pass thru them. It is a widespread phenomenon that takes place at different scales: the large mass of soil brought up among the exposed roots of a wind-toppled oak tree and the few-millimeter thick sediment layer disturbed along the trail of a tiny aquatic snail are both examples of bioturbation.

A recent review by Meysman et al.1 presents a good introduction to the subject. Charles Darwin was apparently the first naturalist to approach bioturbation from a scientific angle. The result was his book The formation of vegetable mould, through the action of worms, with observations on their habits.

Bioturbation is especially obvious on the ocean floor where many mollusks, worms and crustaceans live buried in the sediment while others plow thru it in search of food. The result is a complex interaction of biological and physical events: "Benthic organisms modify the microtopography of the ocean floor via pellet production, track formation and different types of construction, such as mounds and pits... This biologically induced roughness modifies the hydrodynamics above the sediment layer, which in turn affects erosion and resuspension."

However, Meysman et al. point out that "for most landscapes and seascapes, the importance of the biological imprint compared with purely physical processes remains largely unknown." To return to my original example, how significant is really the reworking of aquatic sediments by snails when a flooding creek after a heavy rain storm can remove or deposit more sediment than can a river full of snails over many, many generations?

When a process is as common as bioturbation, it becomes difficult to rule out what is not bioturbation. Is the imprinting of footprints in mud count as bioturbation? If the formation of footprints had a significant impact in the lives of other organisms, I suppose the process would be bioturbation. What about the weathering of rock outcrops by microorganism and plant roots? Many rock types start out as sediments and weathered rocks eventually turn into soil. But where do we draw the line?

Meysman et al. also assign a "revolutionary" position to bioturbation in the grand scheme of evolution: "Benthic fauna had to adapt to the newly emerging bioturbated sediment conditions, thereby fuelling the 'Cambrian explosion'". But that is pure speculation.

1Filip J.R. Meysman, Jack J. Middelburg and Carlo H.R. Heip. Bioturbation: a fresh look at Darwin’s last idea. Trends in Ecology and Evolution 21:688, 2006. Abstract & Glossary

29 January 2007

Marissa-Cat gets intimate with the deer skull

In her comment on this post, Deniz inquired if my cats weren't interested in the deer skull from a few weeks ago. Yes, of course.

After the skull was cleaned in hydrogen peroxide, I offered it to Marissa-Cat. Her initial response was to smell the skull carefully for a minute or two.


This was followed by head rubbing that lasted another minute or so. This sequence of events, careful smelling followed by head rubbing is a characteristic behavior of domesticated cats when confronted with a new object.


Why do cats rub? Cats have glands producing fatty secretions between their eyes and ears, around their lips and on their chins1. When they rub their heads against people, other cats or inanimate objects, they are apparently marking them with the secretions of those glands. In the picture above, Marissa-Cat appears to be using the glands between her eyes and ears.

But what is the function of scent-marking? The brief discussions of this behavior that I have read1, 2 do not offer clear answers. The imparting of a smell, if that is indeed what the cat is doing, on whatever it is rubbing against, may be the cat's way of accepting the thing, such as a deer skull, into its world. After the smelling and rubbing ritual is finished, the object now smells like the cat and so it is a part of the cat's world.

But this doesn't quite explain why Marissa-Cat gets very rubby-dubby against my legs when she is hungry.

1Turner, D.C. & Bateson, P. The domesticated cat: the biology of its behaviour. 1988.
2Morris, D. Cat watching. 1986.

27 January 2007

A recipe for snail eaters

Kapadokya Lezzeti (Cappadocia Flavor), a book by Sula Bozis, originally published in Greek and recently in Turkish, brings back the gastronomical culture and the recipes of the Turkish-speaking native Greeks of Anatolia, especially of the Cappadocia and Karaman regions. The majority of the Anatolian Greeks were forced to migrate to Greece during the 1924 population exchange between Turkey and Greece that followed the Turkish-Greek War of 1919-1922. They took with them, to eventual oblivion, their centuries old culture and traditions and the unique script, Karamanlica, that they used to write Turkish.

What was lost then, now lives in books, photographs and recipes. So here is how the Anatolian Greeks cooked their snails, in translation from Kapadokya Lezzeti. Sula Bozis traces the recipe to Uluağaç, a village of Niğde in central Turkey.

Snail yahni1

1.5 kg large snails
3 chopped onions
2 tablespoons tomato sauce
2-3 bay leaves
1 tea glass2 oil
vinegar, salt, pepper

Place the snails in a large shallow pot filled with water and vinegar, close the lid and secure it with a rock on it so the snails won't escape. Replace the water once every 2 hours3. Transfer the snails to another large pot with boiling salted water; boil for 15 min. Drain the snails, let them cool and then remove them from their shells using a sewing pin.

Sauté the onions lightly in oil. Then add the tomato sauce, water, bay leaves, salt and pepper. Bring to a boil, add the snails, simmer until most of the water evaporates. Serve hot.

Afiyet olsun!

1Yahni, originally from Persian, in the Anatolian lexicon means a dish made with sautéed onions, tomate sauce and meat.
2A traditional Turkish tea glass with a narrow waist. There are a couple of them in the photo of Peter Throckmorton in this post.
3The recipe doesn't specify how long the snails are kept in vinegar-water.

26 January 2007

I am a peer reviewer (and a beer reviewer)

In a post back in June of last year I explained why I had turned down a request from an editor of a journal to peer review a manuscript on cyclodextrins. I also noted that during my approximately 7-year "career" in malacology, I had not yet been asked to review a manuscript dealing with snails. That has now changed. Yesterday I received by e-mail from the editors of the Venezuelan journal La Revista Científica UDO Agrícola a manuscript to review. And this one is about snails.

OK, Revista Científica UDO Agrícola may not be one of the top-rated journals (I didn’t even know it existed until yesterday), but, hey, it’s a serious, peer-reviewed scientific journal and that's good enough for me. And obviously, the editors are taking their duties seriously and, as a reviewer, I will be taking my responsibilities seriously.


25 January 2007

Eventually the truth will set us free

Back in October of last year, I noted my belief that the apparent power of religion in the U.S. is nothing more than a manifestation of its death struggle. Now, I am happy to see that the philosopher Daniel C. Dennett shares my opinion. In response to the Edge magazine’s question "What are you optimistic about?", this is what he said:

I’m so optimistic that I expect to live to see the evaporation of the powerful mystique of religion. I think that in about twenty-five years almost all religions will have evolved into very different phenomena, so much so that in most quarters religion will no longer command the awe it does today...

The religious fervor of today is a last, desperate attempt by our generation to block the eyes and ears of the coming generations, and it isn’t working. For every well-publicized victory–the inundation of the Bush administration with evangelicals, the growing number of home schoolers in the USA, the rise of radical Islam, the much exaggerated “rebound” of religion in Russia following the collapse of the Soviet Union, to take the most obvious cases–there are many less dramatic defeats, as young people quietly walk away from the faith of their parents and grandparents. That trend will continue, especially when young people come to know how many of their peers are making this low-profile choice. Around the world, the category of “not religious” is growing faster than the Mormons, faster than the evangelicals, faster even than Islam, whose growth is due almost entirely to fecundity, not conversion, and is bound to level off soon.

Those who are secular can encourage their own children to drink from the well of knowledge wherever it leads them, confident that only a small percentage will rebel against their secular upbringing and turn to one religion or another. Cults will rise and fall, as they do today and have done for millennia, but only those that can metamorphose into socially benign organizations will be able to flourish...

Let us all keep up the good work.

24 January 2007

A failed slug rescue


Early yesterday afternoon a slug, identified as Limax maximus, was found in a semi-conscious state on a cold and dry concrete path. A large stain of shiny dry slime behind it was a poignant reminder of its final struggles. After the initial assessment revealed that the victim was responsive to touch, it was quickly transferred indoors and placed in a petri dish of water on its left side so as not to block its breathing hole. The initial prognosis was considered good, because, as seen in the photo below, the victim could open its breathing hole unassisted.


Subsequently, however, when it was noted that the victim's condition had not improved after several hours of intensive water therapy, it was decided to pull the plug. The victim, who was originally thought to be an illegal alien from Europe, was later determined to be a naturalized citizen of this country. A burial in 70% ethanol is being planned, followed by an exhumation and an autopsy.

Fama semper vivat

23 January 2007

Puffball releasing spores


During my walk today, I saw a couple of these cute little mushrooms, puffballs, growing out of a cushion of moss at the base of a tree. When I poked them with my finger, a cloud of spores would be released thru the opening at the top. I took about 20 shots, but only one of them captured the spore cloud.


What triggers the release of spores when there are no photographers around? Perhaps, a heavy enough animal stepping on the "ball" of the mushroom? Or, a strong wind?

22 January 2007

Deer skull soup with free radicals


Following the advice on this page, I soaked the deer skull from a week ago in hydrogen peroxide for several days. It is much cleaner now and the sulfurous smell it had is mostly gone.

The decomposition of hydrogen peroxide generates oxygen, which is what makes hydrogen peroxide an oxidant (and also useful as a rocket fuel component)

2H2O2 --> 2H2O + O2

According to Frost & Pearson1, the decomposition reaction is very slow in the absence of a catalyst. Various metals and even rough surfaces can apparently act as catalysts and speed up the above reaction. Furthermore, in the presence of certain catalysts the decomposition mechanism generates free radicals, such as HO. and HO2. that are very reactive. I suspect it is the free radicals, more so than the oxygen, that are responsible for the bleaching and disinfecting properties of hydrogen peroxide solutions.

Bon appétit!

1Frost & Pearson. 1961. Kinetics and Mechanism.

20 January 2007

All slime trails lead to the apple


One morning a couple of weeks ago I stepped out on the deck overlooking the backyard. Something shiny in the sun caught my eye. It was an aggregate of slime trails left by slugs on a long brick. Like the railroad tracks converging at a central station, they were all directed to an adjacent apple core; obviously a favorite slug food.

When I started writing this a half an hour ago, I realized I should have looked under the brick to find the slugs that had left their slime on it. I got curious to see if I could find any 2 weeks later. Grabbed my camera and went outside. Sure enough, there were 2 Deroceras reticulatum, one in the mud and the other stuck on the underside of the brick. I don't know how they survive the freezing temperatures we've been having in the evenings.


19 January 2007

Springtail before it sprung away


I saw this little springtail—barely a millimeter long—sitting on a mushroom on a rotting trunk in the woods last weekend. I took 2 photos of it before it deployed its furcula and disappeared into thin air.

More info on springtails (order Collembola) is available here.

18 January 2007

Does organic farming benefit local biodiversity?

A study by Fuller et al. published in Biology Letters1, evaluated habitat and biodiversity differences between 89 pairs of organic and non-organic farms growing cereal crops in England.

The hedges on organic farms were higher and denser than those on non-organic farms, but the numbers of trees or the numbers of tree and shrub species in hedges were not significantly different between organic and non-organic farms. Hedges provide habitat for plants and animals. That and the exclusion of synthetic pesticides from organic farms would be expected to create a higher biodiversity on them. The findings were, however, mixed.

The mean plant species densities were significantly higher on organic than on non-organic farms. The mean species densities of spiders (but only on pre-harvest crop areas) and bats were also significantly higher on organic than on non-organic farms. Mean species densities of birds and carabid beetles, on the other hand, were not significantly different between farm types, although the mean abundances of birds and carabids (on pre-harvest crop areas) were significantly higher on organic than on non-organic farms. One exception to these trends was the mean species density of carabids (on post-harvest field boundaries) that was significantly higher on non-organic than on organic farms2.

Many other factors beside farming practices probably influence the biodiversity on a given farm. The authors suggest that the proximity of a farm to population sources, that is wild(er) areas may be one important factor: "Many organic farms are isolated units, embedded in non-organic farmland managed with conventional levels of pesticide and fertilizer inputs, often coupled with relatively low levels of habitat heterogeneity, which inevitably affects species colonization."

1R.J. Fuller et al. 2005. Benefits of organic farming to biodiversity vary among taxa, Biology Letters, Volume 1, pages 431–434. Full text
2The mean species density of carabids on pre-harvest field boundaries was also higher on non-organic than on organic farms, but the difference was not statistically significant.

17 January 2007

Yocto yok!

The Turkish word yok is quite versatile. My dictionary has a half a page of entries for it. Yok primarily means "absent, missing, not available", as in ekmek yok (there is no bread). In casual conversation, it frequently means simply, "no".

Geldiler mi? (Have they come?)
Yok (No).

Yok is also used in many phrases with negative connotations except in the double-negative construction Yok yok where it creates an indirect positive: there is nothing missing.

The 13 January 2007 issue of the New Scientist explains the origin of the relatively recent scientific prefix yocto for 10-24. It was created by adding an apparently arbitrary "y" to the Greek word for 8 okto (1000-8=10-24).

It, of course, makes perfect sense. If all one has of something amounts to only 10-24 gram, one certainly has yokto!

A stinky bloomer in January


During last Monday's outing in the woods, I ran into a field of skunk cabbages (Symplocarpus foetidus), some of which were already blooming. The picture shows 2 spathes, each with a spadix (flower head). The numerous little whitish knobs covering the flower heads are the actual flowers.

The rest of the week the temperatures are predicted to go below freezing in the evenings. I wonder if the skunk cabbages will survive (they do produce their own heat).

16 January 2007

The book is out!

The first ever anthology of best posts from science blogs, The Open Laboratory: The Best Writing on Science Blogs 2006, has been published.

As noted previously, this post of mine is included in the book along with 49 others. More info is available on Bora Zivkovic's blog who edited the book.

Now, we have to work harder to maintain the quality.

Yesterday's find


Taking advantage of another spring-like day in the middle of the winter, I spent almost 2 hours wandering in the woods yesterday. This deer skull was one of the highlights of the day.

It is an almost perfect specimen with 2 complete rows of teeth (the bottom jaw is missing, of course). It is also quite clean mostly because it was not directly on the ground, but was resting on a fallen log as you can see in the picture. However, it has a peculiar permeating sulfurous smell. Brushing it with window cleaner, which contains isopropyl alcohol and some detergent didn't help. I am going to soak it in hydrogen peroxide tonite.


15 January 2007

The one that didn't make it


This is a Monacha syriaca shell—one of the specimens we collected last summer in Turkey. Its aperture is almost perfectly sealed by its calcerous epiphragm. What appears to be a hole at the bottom doesn't open to the inside of the shell. There is only a very narrow, short gap, visible at the top corner of the epiphragm, that the snail may have left open for air exchange, although I am not sure if it goes all the way thru the epiphragm to the other side.

The snail was obviously ready for the long, hot, dry Mediterranean summer.

But, the shell is empty; there is no snail in it. When it is backlit, the light shines thru the shell, except at the apex where there is some dark matter. And there is no hole anywhere in the shell.


The snail died, decomposed and dried up. It couldn't survive the heat or the lack of water or something else. Its sealed home became its sealed coffin.

13 January 2007

Crayfish chimney


Crayfishes, despite what their name suggests, are not fishes, but freshwater crustaceans resembling small lobsters. They are quite common in the creeks that run thru the woods near my house. Occasionally, I encounter their chimneys, the openings of their burrows.

According to the literature1, 2, some species of crayfishes spend most of their lives in burrows, while others burrow for various reasons, for example to escape desiccation during times of drought or to move below the frost line during winter.

Different types of crayfish burrows (from Pennak). X marks the place where the crayfish was found.

I don't know what type of a crayfish had made this chimney that I photographed last September. It was on muddy ground near an inlet of Little Seneca Lake that had become too shallow for a crayfish to live comfortably. Perhaps, in this case, the crayfish was hiding in the burrow underneath this chimney waiting for the water level to rise.

1Pennak. Fresh-Water Invertebrates of the U.S., 3rd ed., 1989.
2Hobbs (Chapter 22) in Ecology and Classification of North American Freshwater Invertebrates (Thorp & Covich, eds), 1991.

12 January 2007

Natural selection speaks

Pearls Before Swine by Stephan Pastis

Posts on natural selection:
Falcons hunting pigeons
Wild dogs hunting impala
Predators and natural selection in lizards

A book for bivalve collectors

bivalvesbookIf you are going to Florida to collect seashells, take this book with you. The Bivalve Seashells of Florida by Trish Hartmann should become an indispensable field guide for many years to come. It is well written and has nice sharp color pictures of most bivalve mollusks you are likely to find. As the author indicates, the book should also be useful, as species' ranges overlap, for collectors along the northern coasts of the Gulf of Mexico as well as for those in the Caribbean.

In addition to species descriptions, the introductory chapters give information on taxonomy, shell nomenclature, ecology, habitats, anatomy and collecting methods; the basics that every novice should learn. The discussion of the bivalve anatomy, however, could have used a diagram to better illustrate the general organization of bivalve anatomy. And a page or two about bivalve evolution would also have been quite appropriate.

Many US-printed field guides I have seen over the years still inexplicably stick to inches as their sole measurement unit. I commend Trish for using both inches and millimeters. My only other criticism is that I think a shell size range rather than the maximum size given in this book would be more useful. For example, Tucker Abbott, in the 1954 edition of his American Seashells gives (in inches) size ranges.

The Bivalves of Florida is available directly from the publisher, the Anadara Press.

After I mentioned this book briefly in a previous post, Trish Hartmann kindly sent me a courtesy copy. However, my review was not biased by her favor.

11 January 2007

Why did the earthworm climb the tree?


I saw this earthworm moving horizontally on the wet trunk of a live beech tree last Saturday morning when I was actually looking for slugs. It was about knee high above the ground. A few seconds later, it started crawling down towards the roots.


Everything that grows on beech trunks, the fungi and the algae, are rather flat. I don't think an earthworm's mouth anatomy would let it eat any of that stuff, although I could be mistaken. I suspect this individual was simply exploring, taking advantage of the wet trunk to experience life above the ground for a change.

10 January 2007

Throckmorton down under the Aegean

It was the spring of 1958. Peter Throckmorton (1928-1990), an American photographer, diver, freelance journalist and above all, adventurer, was returning to Europe from a filming assignment in India. While in Istanbul, he heard that a bronze bust of Demeter had been found by fishermen off the southwestern coast of Turkey. He decided to investigate.

The rest is history. And that history is told in Throckmorton's 1965 book, The Lost Ships, which I recently finished reading.

A shipwreck enthusiast since childhood, Throckmorton wanted to find out where the bust of Demeter had come from. So he went south, first, to Izmir on the west coast, where he became friends with the Turkish photographer, diver Mustafa Kapkin. With Kapkin as his guide and translator, he then proceeded to Bodrum, which was then the hub of Turkish sponge divers. There, the two of them befriended divers, spent with them long nites eating, smoking lots of cigarettes and getting drunk in rickety restaurants. They also learned the locations of the ancient wrecks the divers had been spotting for years along the bottom of the Aegean.

During the days, they did foolishly dangerous dives using homemade scuba gear. They survived and eventually managed to obtain better equipment and assemble a team of divers and started exploring the wrecks in the company of sponge divers along the Aegean coasts of Turkey1.

One of the amusing parts in the book is Throckmorton's unsuccessful attempt to get away from Turkey's peculiar pseudo-homosexual, female-shy male culture that he disliked (and I can't blame him).

I set out for [the Greek island of] Kos, looking forward to a room by myself, a shower, a meal all alone in a shady cafe, perhaps even reading a magazine. The greatest luxury of all was the idea of seeing women. The strange life I had been leading in Bodrum started me thinking about the whole question of the Turks' attitude toward women and, in a way, my own. At the moment women were more important symbolically than as actual sexual objects. I was not interested in women physically when I was diving, for like most divers, I was always tired. What bothered me in Bodrum was the absence of the idea of women as possible companions. I was not demoralized so much by the absence of women as by the suspicion that nubile women didn't really exist at all. I wanted to sit and watch the pretty girls of Kos walk by, not necessarily even speaking to them, but simply renewing my imagination with the assurance that pretty girls actually existed in the world, wearing nice clothes so that men would look at them.

We chugged into the harbor on the rotten old wreck that served as the twice weekly ferryboat, and I was struck by the beauty of the little ships in Kos harbor. The caïques of Kos, like the women, were well painted and kept with pride, unlike the shabby ships of Bodrum. But there was no hotel space in Kos and I had to accept the captain's invitation to sleep on the dirty caïque with the rest of the men from Bodrum. I was stuck with friends from Bodrum during breakfast, lunch, and dinner.

Later, he relocated a bronze age wreck off Cape Gelidonya in southern Turkey that had been first spotted by a sponge diver. After returning to the U.S., Throckmorton was able to convince a young archaeology student, George Bass, that the Cape Gelidonya wreck was worth excavating. The 2 of them returned with a motley team of Americans, Turks and Europeans and excavated the wreck over the summer of 1960. Cape Gelidonya was where scientific underwater archaeology more or less originated. The Institute of Nautical Archaeology at Texas A&M University has information and photographs of the Gelidonya excavation.

Throckmorton was a good writer2 and this was a fun book to read except for one sentence where he seems to have lost his common sense to include a hearsay claim about something outrageous that Turkish villagers on the Bodrum Peninsula were said to have committed against the remains of some Greek soldiers during World War II. The story is so nonsensical that I am not going to repeat it here (it's on p. 134 of the book). The moment I read it I wrote it off as untrue, but only after I read Throckmorton's "disclaimer" about it at the end of the book did I find my instinct confirmed: Throckmorton had heard it from a Greek captain who, however, could not have witnessed the purported event personally, because at that point he would have already left Turkey. In other words, it was obviously a rumor told by one Turk-hating Greek to another, probably many times, before it reached Throckmorton. The perpetuation of an incriminating, yet unconfirmed and ugly story was Throckmorton's inexplicable stab in the backs of his sponge diver friends in Bodrum.

Throckmorton at his typewriter in Bodrum with cheap Turkish cigarettes and Turkish tea.

The artifacts Throckmorton and Kapkin found during their dives formed the nucleus of the collections of the museum they started in the Castle of the Knights in Bodrum in the late 1950s. Back then, Throckmorton wrote, the castle was being used as a stable for donkeys. It now houses the Bodrum Museum of Underwater Archaeology. The museum's website has a short tribute to the contributions of Throckmorton, Kapkin and Honor Frost, the British archaeological illustrator who worked with them in Bodrum.

As for the wreck from where the Demeter bust may have come from, its whereabouts is still a mystery as this 2004 report by Australian archeologists shows.

1In my review of Lord Kinross's Europa Minor, I mentioned that a sponge diver in Bodrum had told Kinross about the wreckages of some British aircraft shot down during World War II. Throckmorton dived to one of those planes, but could not recover anything identifiable.
2However, Throckmorton misspelled almost every Turkish word he included in his book, including the name of the sponge boat on which he spent many days, Mandalinci (pronounced, Mandalindji). Throckmorton's, Mandalinche, even if it was an attempt at phonetic spelling, should have been avoided for accuracy (the correctly spelled name of the boat was, of course, written on its bow and is clearly visible in one of the photographs in the book).

MAM 2007

Ninth almost-annual meeting

Saturday 31 March 2007 10:00 am
Delaware Museum of Natural History
4840 Kennett Pike, Box 3937, Wilmington, DE 19807, U.S.A.
Host: Dr. Liz Shea, Curator of Mollusks

The 9th almost-annual meeting of the Mid-Atlantic Malacologists will occur Saturday 31 March 2007 at the Delaware Museum of Natural History (DMNH) in Wilmington, Delaware. This one-day gathering is designed to facilitate contact among professional, amateur, and student malacologists who are interested in any aspect of molluscan biology. There are no dues, officers, abstracts, or publications. Meeting and parking are free of charge. Participants are encouraged to present and discuss data, compare notes on methods and problems, and catch up with colleagues and friends. Presentations (15 minutes max.) are very informal and cover topics as diverse as current research, trip reports, and collection issues.

For more information or to say you will attend and/or give a talk,
please contact Liz Shea at eshea AT delmnh.org.

09 January 2007

Wilson's fundamental laws of biology

The New Scientist magazine's latest free science podcast* (dated 5 January 2007, available on this page) has an approximately 5-minute excerpt from a talk the Harvard biologist Edward O. Wilson gave last December in New York at a celebration of the New Scientist’s 50th anniversary.

Wilson briefly discusses the nature and the current standing of biology, which he calls the "paramount science", and then proposes 2 fundamental laws of biology.

1. All of the phenomena of biology are ultimately obedient to the laws of physics and chemistry.

2. All of the phenomena of biology have arisen by evolution thru natural selection.

Of course, it is not quite accurate of me to call them Wilson's laws, because Edward Wilson didn't come up with them.

That all biological phenomena obey the laws of chemistry and physics without the need for a vital force (or, for divine intervention, for that matter) was established by the collective scientific effort of the late 19th and the early 20th centuries.

And the idea that evolution by natural selection is responsible for all biological diversity was first proposed by Darwin and Wallace in 1858 and has since been demonstrated, again, by the collective scientific effort, to be a fact backed up by insurmountable evidence.

We should follow Wilson's lead and teach and demonstrate the validity of these laws and defend them, if need be.

*Note added 28 February 2008: The New Scientist has since stopped producing regular podcasts and the existing archive doesn't list the podcasts from before April 2007. However, the said podcast is available here at the New York Academy of Sciences web page.

The good, the better and the best

Coturnix at A Blog Around the Clock is editing the Science Blogging Anthology 2006 that will be published as a book pretty soon, in fact, by the end of next week.

I am delighted that this post of mine has made it to the final 50 from among 218 entries and will appear in the anthology. The other 49 posts are listed at A Blog Around the Clock.

This is the first-ever Science Blogging Anthology (a collector's edition, perhaps?). It may be a minor effort in our struggles to introduce scientific thinking and to disseminate scientific knowledge to the masses, which is something we desperately need, especially in the U.S., but it is a good start and will hopefully become a yearly tradition. I congratulate Coturnix for undertaking this project.

08 January 2007

Saturday's slug


I went slug watching last Saturday morning. This is something that I normally do in the spring, but Saturday's weather was indeed spring-like. Moreover, it had rained all day Friday and throughout the nite. So, on Saturday morning the slugs that would normally have been hiding away from the cold, the snow or the ice this time of the year were instead out on the wet trees feasting on the fungi and the algae.

This particular individual was on a small branch on the ground. It is probably a Megapallifera, one of the eastern U.S. natives. They are usually hard to identify without dissection. They leave characteristic feeding tracks on beech trees.

If you watch a slug carefully, you can tell when it is scraping something with its radula, because its head will rock back and forth. This one was doing that when I photographed it.

After I removed the slug to a nearby tree, I broke the section of the branch it had been on and took it with me. Later, under the microscope I could see that the surface of the branch was covered with some sort of crust fungus. There were also lighter colored areas where the top layer of the fungus had been removed (arrows in the picture below). I believe those are the marks left by the slug's radula.

Ruler is in millimeters.

06 January 2007

Is it warm outside or is it me?


Hi 21°C

It is warm outside. The National Weather Service (NWS) had predicted that today the temperature would go up to 21ºC (70ºF) and the last time I checked about an hour ago, it was reported as 21ºC.

According to the NWS summary for December 2006, the average monthly temperature in the Washington D.C. area of 44.2ºF ties it with 1994 as the 10th warmest December on record. The chart below is from the NWS.

You will notice that the 4th column gives the "normal" values. Back in November of last year, Duane at Abnormal Interests had an abnormal criticism of the use of the term "normal" to mean "average" by a local weatherperson. I agreed with Duane back then. But, it turns out that the NWS is also using the term normal in addition to average (and also mean). If I understand it correctly, they use average and mean to denote monthly values and "normal" to denote the average over a longer period (1971-2000).

So far we have had none of that white fluffy stuff that is supposed to fall down from the sky in the winter either.

05 January 2007

Amufe yourfelf with fparks

This is from a letter published in 1755 or 1756 in the Royal Society's Philosophical Transactions, Volume 49, pages 251-254. The original title is A fhort Account of fome new Aftronomical and Phyfical Obfervations made in Afia; and communicated to Matthew Maty, M.D.F.R.S. by his Excellency Mr. [James] Porter, his Majesty's Ambaffador at Conftantinople, and F.R.S.

The reported observations had been made by someone whose identity Porter did not reveal.

The dry country where men could be made electrical was not identified either, but it was presumably the vicinity of Aleppo, in present day Syria.

04 January 2007

Naughty mushroom graffiti


It's art.

03 January 2007

Poor Mr. Mittens


Mittens is a neighbor's cat. He spends most of his time outdoors. We have the key to the neighbor's house. Occasionally, when we are certain that they are not home, we open their door to let Mittens in. And several times a year when they are away, we take care of Mittens and their 2 dogs.

So Mittens knows us and whenever he wants to go inside his house, he comes to our porch and starts waiting. From there he can also spot his owners' cars turning the corner and go after them to be let in.

Ironically, however, Mittens often gets stranded outside when his owners are home, because they don't check up on him and, we wouldn't, of course, just unlock their door from the outside to let their cat in.

We've found Mittens on our porch wet and cold more than once. We now keep an old towel ("Mitten's towel") on the porch with which to dry him. He frequently sits on our old rocking chair and occasionally, perhaps when he is really cold, lets me put the towel around him. Last Monday nite was one of those occasions.

One interesting thing about Mittens is that he recognizes me as a friend only in the front of my house. A few times when he encountered me in the backyard he quickly turned around and ran away even when I was calling out his name.

02 January 2007

New year, new snail: Theodoxus fluviatilis

The scale is in millimeters.

This species has never been on this blog before. Theodoxus fluviatilis is an aquatic snail and I don't often write about aquatic snails. These specimens are from Köyceğiz Lake in southwestern Turkey where we collected for about half an hour one morning last summer.

As its name implies, T. fluviatilis lives in rivers and also in lakes and brackish waters with salinities up to 13 parts per thousand, according to Fretter and Graham1.

Many of the live snails I pulled out from the lake had tiny eggs in rows attached to their shells near their apertures. Fretter & Graham1 describe the eggs as "a flattened sphere made up of approximately equal halves sutured together around the equator." Apparently, the 2 halves are separated when the young snails escape.

Theodoxus fluviatilis with eggs. Snail's operculum is closing the shell aperture.

Another characteristic of this species and its relatives is that as they grow they resorb the inner walls of their shells (that is, the previous outer walls that became the inner walls after they were covered by subsequent whorls). As a result, the inside of the shell becomes a little bit more spacious than it would otherwise be. In the picture below you can see the inside of a T. fluviatilis shell thru the hole I opened in its wall. The diagram shows the location of the missing (resorbed) inner walls that would be seen from the direction of the red arrow. The edge of the remaining portion of the inner wall (blue arrow) gives the false impression of being the columella. The actual columella, which was resorbed, would be located directly under the apex of the shell.

Inside of a Theodoxus fluviatilis shell.

Vermeij2 suggests that the function of resorption of inner shell walls is to increase the available space within the shell. He speculates that in carnivorous species, resorption makes room for the swallowed prey. Increased space inside its shell may also help an intertidal snail to store more water in its shell for times when it is exposed to air. In the case of T. fluviatilis, which is neither carnivorous nor intertidal (although they do live quite close to the shore), I suspect resorption creates more room for eggs.

1. Fretter & Graham. 1994. British Prosobranch Molluscs.
2. Vermeij. 1993. A Natural History of Shells.

01 January 2007

One big sucker

The tick attached to Marissa-Cat's neck right below her mouth. Her nose is at the top.

I felt this tick on the neck of one my cats this morning. My wife and I made several attempts throughout the day to remove it without success. It was deeply embedded and the 4-legged victim, Marissa-Cat, who doesn't hesitate to bite the hand that feeds her if the same hand is attempting a painful or annoying operation on her, wasn't exactly cooperative.

Finally, I succeeded late in the afternoon when she was dozing off on the sofa. Sleepy cats are always easier to handle for about 3 seconds.

The marks on the tick's abdomen were left by the tweezers. The ruler is in millimeters.

The subsequent examination of the 8-legged victim, who got ruptured* during the removal process, revealed that it had left its mouth parts behind probably still in Marissa-Cat's skin. We will be keeping an eye on her neck.

*I was expecting the tick's contents to be redder. Their metabolism must process hemoglobin quickly.