Monday, March 17, 2025

There Is No Watchmaker


Richard Dawkins wrote The Blind Watchmaker in 1986. 

 

(Picture from here.)

 

His intention was to refute the idea that the complexity of living systems made a Creator self-evident. The analogy was of finding a watch implied a watchmaker, a metaphor created by William Paley. I am not a fan of Dawkins in that I think his idea of evolution—especially human evolution—to be far too narrow. But TBW was a good starter book on evolution.

 

Current life origin hypotheses put the start at about 3.7 billion years ago. This is the evidence of life that survived on the early Earth. Earth is about 4.5 billion years old and the conditions amenable to life are supposed to have been present at 4.3 billion years ago. So, there’s a six hundred-million-year gap where life could have started, failed, and restarted. Or, life could have started and left nothing that could be traced until that 3.7-billion-year mark.

 

The current hypothesis of Moon formation is that it was struck from the Earth by a collision from a Mars-like body early on. This would have left the surface of the Earth in a molten state. Unless you want to imagine lava-breathing ichthyosaurs, that pretty much lets out life until things cooled down.

 

The base for what we call complex life—Eukaryotes—seem to show up about 1.6 billion years ago. That means we have something like bacterial life on the planet for 2.1 billion years or so. If they breed like bacteria—say, a division on the order of 1/hour—that’s 50.4 billion generations before we get to Eukaryotes. Maybe more generations since some bacteria divide every twenty minutes. I’d say that should be plenty of time to evolve pretty much anything. 

 

We have no idea if pre-Eukaryotes were like bacteria. We have no idea of “Eukaryotes” actually had all the components that we identify with Eukaryotic cells. That would things like a nucleus, mitochondria, etc. We think it’s likely but it is speculative at best.

 

Animals, whose evolution I am most familiar with, arose about 650-700 million years ago. So, roughly a billion years. Cell division in Eukaryotes is considerably more complex and, understandably, it takes longer—approximately 16-24 hours

 

The Ediacaran period happens just before the Cambrian. In the Ediacaran, early animals developed. These were defined into modern phyla in the Cambria. The Ediacaran began roughly 635 million years ago—barely fifteen million years after Eukaryotes were first identified. We can use sponges as an example. The sponge reproductive cycle can be budding—where a chunk breaks off and ends up somewhere, takes root, and grows—or sexual. In either case, there has to be a minimum time between a larva and the first offspring. If we go by sexual periods, this breaks down to once or twice per year. 

 

We’ve gone now from an hour for generation time, to approximately a day, now to a year. We know of many animal species—us, for example—where the generation time is measured in years. Evolution is the selection of variations within offspring. The irreducible atom of evolution is the generation. While animals can adapt within a generation, the only means by which these changes are realized is in the next generation. Looking at this, we might expect animal evolution to slow down. 

 

Instead, it speeds up. The Cambrian isn’t called the Explosion for nothing.

 

This is the point that if we would invoke a Creator if we were so inclined.

 

We are not.

 

But something happened. 

 

That something is embryonic development. 

 

The embryo is a well of potential. It has to go from a zygote to a larval form (at minimum) containing only the information it starts with. Most zygotes in the animal kingdom are cast into the wild. A few (I’m looking at you, placental mammals) develop within the mother organism. Even there, the mother is walled off from the developing embryo so that there is little interference. 

 

Here’s where we get muddy about the language. We talk about how the “design” of the zygote results in the new organism. Or how the process of embryonic development is like a symphony, each part played and leading to the beautiful. 

 

None of this is true. There is no design. If you boil down what’s in the nucleus for a human you won’t see a gene for blue eyes or red hair. You might see a melanin deficiency that manifests at a particular point in development such that the iris of the eyes is without pigment. You might see a keratin gene get over expressed in the creation of hair follicles. But there is no one gene for the shape of your nose, angle of your neck, or your height. Repeat: there is no design. (See here.)

 

Imagine two dancers on a floor. One dancer moves their arm. The other responds by waving a hand. The first then turns. The other turns the opposite. Both of them are following their own understand of their actions—Dancer 1 knows to move the arm. The other knows to respond with a hand wave. But Dancer 1 does not know that Dancer 2 is going to wave a hand. Dancer 1 does know to respond to Dancer 2’s turn with another turn. To the audience in the balcony, this appears to be a wonderful dance. But neither dancer knows the ultimate goal. Neither dancer even knows there is a dance.

 

The egg of an animal is packed with energy and data—not a design, remember. The first few divisions are self-contained with regard to energy. The yolk of the egg or the material of the placental environment is not immediately consumed. Oxygen is, of course. But for those first crucial divisions, the cells consume material inside. Later, they will take in nutrients from the inside. 

 

As they divide, different cells get different material from the original egg. This is the initial specialization. Even sponge development results in cell specialization. 

 

About thirty years ago, scientists began to realize that there was some kind of developmental module. Not a design as such, but a pre-program that enforces a path in those first few divisions and later, with each division, triggers responses that result in an actual organism. 

 

There is no design in the genes. But there is a design in how the gene interactions play out. 

 

This is where evolutionary-developmental (Evo-Devo) biology comes in.

 

The idea is that there are genes responsible for the development across multiple phyla. These determine body plan. For example, the gene responsible for the development of eyes exists across multiple phyla: arthropods, vertebrates, cephalopods. Where, when, and how they get expressed determines if you get a beetle, possum, or octopus eye. 

 

Is this design? I don’t think so. The gene triggering the eye development does not contain any internal representation of an eye. It triggers a cascade of responses that result in an eye. That’s been useful and is therefore retained. 

 

There are beginning body plan genes—prepared for operation by the egg. These genes determine segmentation, organs, vascularization, and the like. They tend to be lined up in roughly the expression order required by the organism. Changing the order can result in different organs or blood vessels originating in different segments. 

 

Developmental genes of this sort have been found in animals, plants, and fungi. They were a critical step in the origin of complex organisms. But they do not exist in isolation. Each gene responds to and is responded to within the context of its environment. There are past events that prepare the operation of the gene and future events to which it is contributing. We call the some of these bits of DNA “body plan genes” or “regulatory genes” because they are central to the process. But in the absence of their important context, they are just sequences of nucleic acids—like any other bit of DNA.

 

It's a subtle point—we would like there to be a design in place because that would be more understandable to us. Humans design things. Why shouldn’t nature? Why shouldn’t we have a design or a program?

 

I’m going to quote Alessandro Minelli quoting Keller on this one: “More explicit is Keller (2000), who suggests that to speak in terms of genetic programme is to commit a basic error in categorisation: genetic is equated to programme at the same time as epigenetic is equated to data. But development depends not only on genetic memory, but also on the machinery of the cellular structures, which in turn are set in place by cellular memory rather than by genetic information.”

 

I think that just before the Ediacaran Period, this fundamental body plan embryology began to be emplaced. Possibly, cells that cooperated and produced a consistent offspring did better than others. An organism had a few cells that cooperated to produce sex cells. That cooperation became the basis for a coordinated embryologic process. Then, at the beginning of the Ediacaran, these now somewhat complex organisms themselves competed. 

 

Something happened at the end of the Ediacaran. Some have suggested the introduction of predation, changing the world into predator and prey and vastly increasing the natural selection process. There was enough variation in the body plan genes that new forms came into existence. Those that were successful propagated their new forms further. 

 

What happened at that point was a system built to evolve was in place.

 

The rest, as they say, is our history.

 

 

Monday, March 3, 2025

State of the Farm, March 2025


It’s that time of year again.

 

Now we are beginning our planning for the season. This year I decided to be more precise in the planting. I set up some drawings on grid paper, where one grid = 1 square foot. We measured the different gardens and started laying things out. This is still under discussion so I’m not going to share it just yet. Stay tuned.

 

Last year we had a long of fungus problems with the apples, grapes, and quinces. We have five production apple trees and about half a dozen or so crabapples on one of the espaliers. Last year we got actual crabs off some of them. 

 

The problem with the apples is cedar apple rust. This is a fungus that, unsurprisingly, has cedars as the main host. Apples and other related fruit trees get infected from the cedars. Last year was particularly bad. 

 

We have two cedars and while both of them have the rust, the south cedar’s infection is worse than the north cedar. The crabs aren’t badly affected and I attribute that to more resistance and the fact that the crab espalier is far from the south cedar though it is close to the north cedar. 

 

The Granny Smith is so badly infected I think it’s acting as a reservoir. Two other production apples also have bad infections—to the point that they lost all their leaves in August. The remaining production apples have the infection but not has bad—though the Sops of Wine apple lost its leaves early as well.

 

The plan is to cut down the Granny Smith and the two other production apples. We have a ordered a Zestar! As a replacement apple. We’re still looking at other varieties. (See here.) We’re looking at Very Resistant varieties. (Note: according to that table, Granny Smith is resistant. This has not been our experience.) The problem is to find good pollination partners and apples that we like the taste. Apple varieties bloom at different times. Varieties that don’t bloom in the same time period are good pollinating partners. We found a Zestar! orchard locally and liked the flavor. The other Very Resistant varieties were either locally unavailable or didn’t taste good to us. We’re still looking.

 

We planted the new quinces on the same area that we pulled the plums from a few years ago. The plums succumbed to black knot. It affects plums, cherries,  apricots, etc.—any member of genus Prunus. Quinces—being members of genus Cydonia—should not be susceptible. Well, lo and behold, we started seeing what looked suspiciously like black knot on the quinces. We had an arborist over for some work on two other trees and he looked into it. He said it was cedar quince rust

 

Yay.

 

I trimmed off the infected bits and sprayed with a copper fungicide and additional material. We will see.

 

Meanwhile, last year, we also had a problem with grape black rot. It was time to trim back the grapes anyway so I cut them back to within an inch of their lives and sprayed at the same time I did the quinces. 

 

Further spraying is no doubt required and I’ll have to keep up on it if we want to have grapes, quinces, or apples this year.

 

Moving away from the gardens to the wood shop, we attacked a lot of old wood. 

 

Over the years, whenever we had a tree taken down or cut it down ourselves, I saved any wood that seemed pretty enough. This included chestnut, prune, plum, peach, apricot, apple, and hickory. There are probably some others I don’t remember. 

 

I cut them, painted the ends so they wouldn’t split, and put them in a rack to dry out. Fast forward a few years.

 

Two years ago, a hickory split and half fell down on the property. We had to take down the entire tree. The following year a great cherry tree fell on a friend’s property. We also took down a few sumac trees (Native sumac is a big tree. Who knew?) and a couple of apples on a different friend’s property. To make a long story short, I saved as much wood as I could. But were was I going to put it all?

 

Remember that wood I’d already saved?

 

It turned out that I should have debarked them. like to burrow under the bark and into the wood. Some kinds of wood—notably hickory, apple, and prune—seemed resistant. Others, not so much. Chestnut, not at all. Some of the cherry and hickory were small enough pieces that I could store them indoors. So, I went back to my wood and winnowed out the chaff—i.e., wood I had misjudged to be of use or had rotted on me. 

 

Let this be a lesson: use it or burn it. Don’t let it rot.

 

I’ve gone over about half of the old wood and it’s now replaced with hickory and cherry—and some cedar. I never let cedar go if I can help it.

 

That’s it for now.