Paleobotany Of Four Medieval Strongholds

Palaeobotanist Jennie Andersson has analysed four soil samples for me, all from floor layers inside buildings at Medieval strongholds that me and my team have excavated in recent years. There’s one each from Stensö, Landsjö, Skällvik and Birgittas udde. Results were sadly not very informative.

Comments Jennie:

“Overall the fossil and carbonised botanical material in the samples, as well as the recent unburnt material, is meagre … No carbonised cereals were found. Three of the four samples did however contain rather large amounts of unburnt bones and scales from fish plus jurpa, a blanket term för amorphous burnt organic material which may represent bread, burnt food, cooking waste or animal fat. Both the fish bones and the cooking waste probably originate in household cooking and waste management … The presence of burnt weeds such as goosefoot, bedstraw, smartweed and clover (Chenopodium album, Galium spp., Persicaria lapathifolia, Trifolium spp.), all of which thrive on nutrient-rich, sometimes slightly damp and open ground and around farms, tally well with what we may imagine would have been common in a castle bailey or around a farm yard where livestock and people tread about every day and share space.”

Report in Swedish here.

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Meal Remains From Castles: 2016 Osteology Reports

Supported by a grant from the King Gustavus Adolphus VI Foundation For Swedish Culture, osteologist Lena Nilsson has analysed the bones we collected during excavations last year at two Medieval strongholds. Two weeks with 19 fieldworkers at Birgittas udde produced only 0.4 kg of bones, because the site has no culture layers to speak of and the sandy ground has been unkind. But from the following two weeks at Skällvik Castle we brought home 32.7 kg of bones! And now Lena has looked at them all. Here are her reports:

The reports are in Swedish, but the species names and anatomical terms are given in Latin. Birgittas udde was occupied briefly in the 1270s but then seems to have been vacant, though kept in repair long into the following century. Skällvik Castle was occupied from 1330 to 1356 or shortly thereafter.

Lena is available for more work, and I’ll be happy to help readers get in contact with this seasoned osteologist.

Update 29 May: And here’s Lena’s report on the bones from Landsjö Castle 2015.

Purported Metal Casting Mould Identified As Fossil Cast

A little archaeological conundrum found its solution this morning. At an excavation in Motala in the early 00s, colleagues of mine found a cupped piece of hard, greyish brown material with a distinctly patterned inside. They interpreted it as a piece of a lost-wax casting mould and suggested in a 2004 publication that it was for a Viking Period tortoise brooch. I’ve never seen the find live, but I could tell from the pictures that the pattern was certainly not from the Viking Period. I wrote in my 2011 book about the area (p. 119), “the object in question has a shape and a geometrical decoration style that is quite alien to the Viking Period, and must belong with the considerable amount of High Medieval material also found on the site.” Later another similar piece was found at a nearby site, but nobody’s found a good explanation for what was cast in these moulds or when.

Now it turns out that everybody who’s commented on these objects, including myself, has been wrong. My hugely talented and versatile colleague, archaeobotanist Jens Heimdahl, cracked the case.* His doctorate is in quaternary geology, and he’s studied palaeontology as well. Jens explains that the cupped brown thingies with a geometrically patterned inside are in fact fossils of Ordovician echinoderms of the genus Stichocystis! We were all fooled because these are concave casts of a domed animal. Had it been a fossil of the beastie itself, then there would have been no confusion.

Stichocystis fossil.

Stichocystis fossil.

* Jens clarifies:

“The process of identifying the echinoderm was complex and the credit should not go to me. The material was recognised as sedimentary rock rather than clay by ceramics specialist Ole Stilborg, who suggested that the imprint might be from a fossil. Archaeologist Katarina Sköld looked among pictures of sea urchins without finding any parallels, and then sent pictures to me. I confirmed the suspicion of a fossil echinoderm, but was more broad in my guess, suspecting perhaps some kind of crinoid, which sometimes have similar surface patterns. I sent the picture to the palaeontologist Jonas Hagström at the Natural History Museum, and he made the identification. I just had the honour of presenting the result.”

I’m Donating White Blood Cells

I’ve been a blood donor for over twenty years. The other day a doctor called me and asked me if instead of my normal quarterly donation, I’d be willing to give a few extra hours of my time along with a chunk of white blood cells. I said yes.

There’s this transplant patient at a hospital in Stockholm. Like all such patients this person, let’s call her Joan (I have no idea what her real name is), is on immune suppressant drugs to keep her body from tossing out the transplanted organ. She now seems to have contracted a difficult infection. Unfortunately she’s developed antibodies against run-of-the-mill donated blood that would work in most cases. So in order to give Joan white blood cells to beat the infection, you can’t just look at the AB and Rh factors, you need to look at tens of genetic markers until you find a rare match. Me, in this case.

For me, it’s three visits to the hospital. Monday morning, they first checked my health, which turned out to be very good. Then they drew some of my blood and mixed it with Joan’s in a tube to see if it would provoke an immune response. When it did not, they injected me with filgrastim. This is a synthetic analogue of the hormone G-GSF, granulocyte-colony stimulating factor. In the body, G-CSF is secreted here and there, and it causes the bone marrow to make granulocytes and stem cells and release them into the bloodstream. Granulocytes are a category of white blood cells, the immune system’s foot soldiers.

After the doctor and nurse had seen that the injection didn’t cause me to keel over, they sent me off with some dexamethasone pills to take Monday evening. This is a steroid similar to the hormone cortisone, which has a wider range of functions, one of which is apparently to get those granulocytes out into my blood quicker.

The doctor warned me that I might feel a little creaky in the evening from the sudden flooding of my system with unneeded white cells. And I did, like if I had the flu coming on distantly. But I consoled myself with the thought that I was still in much better shape than Joan. This morning I was back at the hospital and got hooked up to a centrifuge. They’re taking blood out of my left arm, spinning it up in the centrifuge until it separates into layers by density, grabbing the bottom part of the layer of white blood cells (the youngest ones), and then sending the rest back into my right arm. They’ll keep at this for two hours, then shoot me up with more filgrastim and send me off with some more dexamethasone, for the whole procedure to be repeated tomorrow morning.

Why am I a blood donor? Why am I doing this complicated thing for Joan, whom I’ll never meet? Well, because I’ve been helped many times by modern medicine, I believe in solidarity and I’ve been taught to feel good about myself when I’m altruistic. And really, it doesn’t cost me much to help out here.

If you want to be all Darwinist, then you can actually say that I’m acting in my evolutionary self-interest. Joan and I are genetically similar. In helping her stay alive, I improve the chances of my genes spreading in the population. Joan is a transplantee and might neither have any kids nor be in any shape to bear them in the future, what do I know. But maybe she has nieces and nephews, whose evolutionary environment will be a bit less harsh if their aunt is around to help feed, protect and raise them. And then they may go on to have five kids each who share a lot of my genes. Anyway, me and Joan are blood kin now.

2014 Castle Excavation Reports

Things are coming together with the post-excavation work for last summer’s castle investigations so I’m putting some stuff on-line here.

  • I’ve submitted a paper detailing the main results to a proceedings volume for the Castella Maris Baltici symposium in Lodz back in May. There are no illustrations in the file, but you’ll find all you need here on the blog in various entries tagged ”Castles”.
  • Osteologist Rudolf Gustavsson has completed his reports on the bones from the two sites (LandsjöStensö).

For the Dear Reader who doesn’t read Swedish, a short summary of Rudolf’s results is in order. As expected, there are no human bones: this is food waste. The material from both sites is dominated by youngish pigs followed by sheep/goat and cattle in roughly equal fragment numbers. Pig parts represented at Landsjö suggest slaughter on site. Chicken was also eaten at both sites. Both sites have fish species that would have been available in the body of water overlooked by the castle. Landsjö’s trench D has large parts of a fox whose femur shows a healed break. It’s from the top layer that probably represents post-Medieval, post-castle slope erosion, and thus doesn’t seem to have anything to do with courtly hunting.

Questions and comments on the documents are most appreciated!

Saturday Morning Mushrooms

blandsvampMushroom picking again this morning, this time in the area between Lakelets Skinnmossen and Knipträsket. Found more velvet and birch boletes than we cared to pick.

  • King bolete, Stensopp/Karl Johan, Boletus edulis
  • Orange birch bolete, Tegelsopp, Leccinum versepelle
  • Velvet bolete, Sandsopp, Suillus variegatus
  • Chanterelle, Kantarell, Cantharellus cibarius
  • Gypsy mushroom, Rynkad tofsskivling, Rozites caperata
  • False saffron milkcap, Blodriska, Lactarius deterrimus

Oh how annoying that the image gallery function is so bug-ridden.

Crayfish Gastroliths

It’s the time of the year when it used to become legal to catch and sell Swedish crayfish (since 1994 there is no limit), and so the grocery stores sell Turkish and Chinese crayfish for a few weeks. The traditional way to eat them is to boil them with dill, salt and a little sugar, and serve them with toast, strong cheese, beer and akvavit. I don’t drink but I love shellfish, so crayfish time is always a treat for me. My wife, being refreshingly unorthodox about traditional Swedish customs, and indeed about all traditional customs thanks to a Maoist childhood, served crayfish with smoked shrimp, aïoli and boiled potatoes last night.

There’s a fun detail about these animals: sometimes you find a pair of little white buttons in their heads. These are known as kräftstenar in Swedish, “crayfish stones”, and gastroliths in English. (The same word is also used for actual stones eaten by crocodiles, birds and other dinosaurs to help digest their food.) As Andrew Hosie of the Western Australian Museum explains:

… crayfish gastroliths … represent a remarkable physiological process to conserve calcium.

Much like people require calcium for strong and healthy bones, so too does a freshwater crayfish to maintain its armour. … As crayfish (indeed all crustaceans) grow bigger, they must periodically shed the exoskeleton and form a new one. To start a new exoskeleton from scratch would require large amounts of new calcium.

The hormones that drive moulting (referred to as ecdysis) trigger calcium carbonate to be removed from the exoskeleton and starts forming a pair of these gastroliths in the stomach. After the crayfish has moulted, the gastroliths are reabsorbed and used in the strengthening of the new exoskeleton. Only freshwater crustaceans form gastroliths because unlike seawater, freshwater has very little dissolved calcium salts, so in an effort to retain calcium, crayfish form these little gastroliths, or even eat the old exoskeleton.

Check out the strange story of what my friend Eddie unexpectedly caught in his crayfish trap.

Friday Mushrooms

zvampHas it really been almost four years since I blogged about mushrooms? This afternoon me and my wife repeated our September 8, 2010 expedition to the hills between Lakes Lundsjön and Trehörningen and picked almost a kilo of mushrooms in a bit more than an hour. We got:

  • King bolete, Stensopp/Karl Johan, Boletus edulis
  • Bay bolete, Brunsopp, Boletus badius
  • Orange birch bolete, Tegelsopp, Leccinum versepelle
  • Birch bolete, Björksopp, Leccinum scabrum
  • Entire russula, Mandelkremla, Russula integra
  • Two kinds of red or brown brittlegill, mild-tasting and thus non-poisonous. Scandyland has more than 130 species of brittlegill, none are deadly and luckily there’s a simple taste test for which ones are good to eat.

Japanese Robot Development Driven By Xenophobia

Reading a term paper by one of my Växjö students, I learned something surprising.

Being a well-read and erudite sort, Dear Reader, you may not be surprised. You already know that Japanese women have been having very few babies each since the 1950s, and that thus there’s a growing shortage of strong young people to work in the care for the elderly. It has gone so far, and the prognosis is so dire, that the Japanese electronics industry is busy developing robots to care for old folks.

What I learned is that the problem is really one of xenophobia. All of Japan’s neighbouring countries across the sea have a completely different demography and offer an endless supply of nursing staff. But it’s politically impossible to lower the bar for entry onto the Japanese labour market. Foreign nursing certificates aren’t recognised. The Japanese voter prefers to have simple automatons caring for grandma when the alternative is a darker-complexioned Philippine person who doesn’t speak Japanese.

Seen from the larger ecological perspective, Japan is simply an isolated human population that is not reproducing well and so will soon be unable to fill its niche. I’m pretty sure neighbouring populations will redress this imbalance within a few decades.

Bread and Microbes

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I found some slightly mouldy bread in the cupboard, cut off the mould and made toast. And I thought about bread and microbes.

For flavour, not as a raising agent, I make sour dough. My method is simple: I mix rye flour with water in a glass, cover it with cling film and put it on the countertop for a week or so. Lactic acid bacteria soon colonise the mix, lowering the pH to make the environment cosy for themselves and deter any other opportunistic microbes.

When the sour dough smells like vinegar I make bread dough with it, adding a second microbe: yeast fungus. The yeast eats sugar in the flour that the lactic acid bacteria haven’t had time to gobble up, and then it emits carbon dioxide gas, causing the bread to rise. (Rubbery gluten protein in the flour makes sure tenacious bubbles form instead of the gas seeping out of the dough.)

Then I bake the bread, which kills off the bacteria and yeast. After 50 minutes at 225 C, the bread is sterile. And delicious! But after a week or so, the bread gets recolonised by microbes, unwelcome ones. This time its another group of fungi, blue-green mould. Tastes awful, so I cut those bits off.

And my toast? I ate it all, sending it straight into the greatest throng of microbes it had ever encountered: the symbiont bacteria in my gut.