State of the Farm, March 2024

I like this time of the year. We’re just starting to pull together what we’ll be doing this year. We’ve been going over seed catalogs and looking at plants since the first of the year.

 

But, even more than that, there’s a certain blasted look to a New England landscape after winter. The snow has flattened the grass. The rot has settled into the garden where we didn’t prepare in the fall. This is the time of year where we start to remedy all that. In that blasted landscape lies infinite possibility.

 

In the two pictures above, the first is a before where I pulled out an old arbor—visible as a black structure—and cleaned up a pair of grape vines. The after picture is the resulting new arbor made from cattle fencing panels.

 

We’ve been doing a lot with these panels for a few reasons. For one, there are a lot of things we like to grow that benefit from trellising and cattle fencing panels make good trellises. Last year we grew beans, cucumbers, and melons on them with good success. 

 

For another, we’re moving away from perhaps the more attractive wooden trellises and arbors in favor of metal. This is mainly because metal structures outlast wooden ones. The wooden arbor in the background is about twenty years old and  needs to be replaced. The cattle fence arbor in the foreground of the second picture should outlive me. 

 

We’ve decided against doing runner beans again. They grew well but I’m not happy with the taste. We’ll replace them with more pole beans. In addition, we want to grow pinto beans. We found a source of good beans with Baer’s Best Beans. Pintos can be raised as either a half-pole bean or a bush bean. We tried them last year without success but I think that was because I asked too much from the plantings inside the arbors. 

 

We’re going to try a succession planting with early spring peas, followed by beans, followed by fall peas. I very much like pea soup. This will give the trellis double duty.

 

We’re going to try sugar beets again—in spite of the failure from last year. We tried to make sure from them but the impurities in extract made it hard to manage temperature. I ended up with a taffy that tasted like grass. Not great. This year we’re going to attempt to filter the syrup and see if that helps.

 

We have two new fruit plants, a goji berry and a new kiwi. We’re still talking about where to put them. Turns out Wendy had ordered a new kiwi for the kiwi/grape arbor and I’d forgotten when I picked one up at Tractor Supply. The goji berry will replace a Manchurian apricot that wasn’t doing well.

 

We finally processed the medlars we harvested last year. In previous years we would get one or two. But last year we got more than a dozen. We tried to turn them into jam but the temperature got away from us and they ended up being a very tasty soft candy—more of a taffy, really. Maybe this fall we can bit the bullet and make hard candy out of them.

 

One experiment we’re trying is goldberries or groundcherries. These are a member of the tomatillo family only much, much sweeter. More like a berry than a tomatillo. We had some this winter from the market and they were quite tasty. More to try.

 

One thing we’ve been trying to do is move away from hybrid seeds. Hybrid seeds come from cross breeding two different varieties. Often, the result is quite strong but they do not breed true in the second generation and consequently are no good for seed saving—which we are trying to do. Heirloom seeds are usually not hybrid.  We have to be careful, though. The reason people generate hybrid seeds is they often have good disease resistance or other valuable qualities the varieties themselves don’t have. It doesn’t make sense to get a nice heirloom cabbage only to see it eaten by pests because it has no resistance.

 

The alternative is called open pollinated seeds. This means that they breed true when pollinated with each other. But that has its own issues. If you plant one open pollinated variety of corn next to a second open pollinated variety, the result can be a hybrid—defeating the reason you started this confusion. We have a couple of varieties of the same vegetable and we’ll have to plant them far enough apart the wind and insects don’t cross between them.

 

We invested again in more Birdie Beds this year. Two more big ones to replace a long raised bed that has finally rotted away. We like them a lot for many of the same reasons we’ve been moving to metal trellises and arbors. In addition, they are tall enough I don’t have to bend down to work them. I’m getting less flexible every year.

 

That’s the news. Now, it’s time to go out there and start preparing (ripping apart) the garden for spring.

 

 

Teeth

I decided to talk about teeth today for purely personal reasons.

 

(Picture from here.)

 

Teeth are a structure unique to vertebrates. There are similar feeding structures in some invertebrates. Some molluscs have a tongue-like radula that is studded with chitinous bits that serve a similar function. But these bear no embryonic relationship with vertebrate teeth.

 

A tooth is a hard structure in the jaw or mouth of vertebrates possessing them. Some have deep roots as in mammals. Some do not. They use dentine as a hard structure that is often capped with enamel. Teeth development is quite different among the different vertebrate classes. Turtles and birds have lost their teeth, replacing them with what is assumed to be a less expensive alternative: beaks. In both turtles and birds, there was an evolutionary stage where both beak and teeth coexisted. Later, tooth growth was inhibited and only the beak remained. Interestingly, the platypus has no adult teeth but has an egg tooth similar to reptiles and birds to aid in hatching.

 

Once teeth were introduced to vertebrates, they were subject to natural selection and from that an enormous variation reflecting form and function. It is clear that carnivores have sharp, tearing teeth and herbivores have flat grinding teeth, though this is a serious simplification. However, there can be no natural selection without natural variation. One can deduce that since natural variation has been so well rewarded across vertebrates that variation in tooth expression has been preserved. You can’t get sharp tooth carnivores and flat tooth herbivores if there isn’t variation in tooth form for natural selection to act on.

 

The scales of sharks, called dermal denticles, and their teeth derive from the same embryological mechanism. Both have an interior cavity surrounded by dentine, a blood supply, and a nerve. This is one basis of the outside-in hypothesis of tooth origin.  The alternative hypothesis, the inside-out idea, is shown with extinct placoderms, who have tooth-like structures in their palate. 

 

Mammals have a single jawbone, the mandible. Reptile jaws are made up of several different bones. The bones of the mammalian middle ear derive from those jaw bones in the reptile. Consequently, one would expect significant variation in tooth development. 

 

Lizards have acrodont or pleurodont teeth. (See here.) Acrodont teeth are sharp and pointy. They’re not attached strongly to the bone. Lizards, for example, do not have tooth sockets. (See here.) Acrodont teeth are usually not replaced. Eventually, as the teeth wear, the biting surface becomes the underlying bone.

 

Pleurodont teeth have long roots. They are attached directly to the cheek side of the jawbone but not the tongue side. They are held in place with ligaments. While they are more strongly attached to the jawbone, they are not that strongly attached. Those big teeth on the Komodo Dragon Lizard? Pleurodont teeth. 

 

There are ancient, extinct reptiles with complex tooth forms. (See Priosphenodon here.) These have similar complexity to mammalian teeth with dentine and enamel caps. These could have been inherited since mammals and reptiles diverged long ago. This is likely a case of convergent evolution in that selective pressures triggered Priosphenodons to come up with similar structures. 

 

Crocodiles, on the other hand, have socketed teeth similar to mammals. As do dinosaurs. This kind of dentition is referred to as thecodont, and used to refer to the stem reptiles from which dinosaurs, pterosaurs, and crocodilians derived. 

 

Amphibians often have teeth though some frogs and other groups have lost them. Those teeth that remain are either in the rear of the mouth or the front and are small. Amphibians have lost and re-evolved teeth several times over the last 200 million years.

 

Which brings us to mammalian teeth.  

 

As I said before, mammals lost the complex lower jaw of reptiles, using a single bone, the mandible act as a jaw bone. Other bones of the jaw migrated to new locations and purposes or were lost entirely. Unlike lizards, mammalian teeth have deep roots, embedded in the mandible and surrounded by bone on all sides. It takes a significant effort to remove a mammalian tooth from the socket. I have personal experience with this.

 

Often, mammals are diphyodonts—they produce two sets of teeth in the organism’s lifetime. In humans, these are the baby teeth and the adult teeth. Monophylodonts have a single set of teeth for the organism. Polyphyodonts have more than two. Some are a blend. Elephants, for example, have a baby tooth tusk that is dropped and replaced by a permanent tusk. The tusk represents the incisor of mammal teeth. The elephant has six sets of four molars. As one wears down, it is replaced.

 

Humans—and, by extension, other primates—are typical mammals with diphyodont teeth. In our history, like many groups, we’ve had vegetarian relatives (e.g., gorillas and orangutans) and omnivores (humans and chimps.) Their teeth reflect that difference.

 

One would think that primitive human beings would have died out long before now because of the way their teeth decay. Decay requires a tooth surface, the appropriate bacteria, fermentable carbohydrates, and time. The latter two might have been in shorter supply in ancient human beings. I.e., fewer sugars and a shorter lifespan. This suggests farming might have been the problem.

 

However, a 15,000 year old find in Morocco, long before farming, gives evidence otherwise. This find showed that they were eating a particularly soft species of acorn that becomes sticky when cooked. Sweet material adhering to the teeth—well, you get the idea. Dental hygiene was not well known at the time. Long before, back in the days of Lucy, there was a shift in diet that caused a change in our ancestors’ teeth. (See also here, here, and here.)

 

I close with a quote from Jonathan Swift: “I’m as old as my tongue and a little older than my teeth.”