The Deadly Tomato

 

As I walked through the weeds between the early-successional trees in the field about which I earlier wrote, I noticed a Solanum dimidiatum weed (horsenettle). It was in the same genus as the potato, a close relative of the tomato. And it had what looked like little green tomatoes on it. This is the time of year when tomatoes are really good. But if you think these tomatoes might be delicious, think again. The entire plant is filled with toxins that are dangerous, even deadly, to most animals.

 

[Photo from Carolina Biological Supply Company] 

The horsenettle plant expends a lot of its energy creating these toxic compounds [what are they]. Expensive they may be, but they protect the plant from having its leaves eaten by most animals. But there is at least one group of animals that can eat the leaves as if they are not toxic at all. The sphinx moth (Sphingidae) caterpillars (hornworms) of the genus Manduca can eat them with little effect on their growth. I know this because I have measured the growth of hornworms when they ate ground-up horsenettle leaves and when they did not; their growth was the same. The toxins do not protect the horsenettles from hornworms, but in many cases, there are no hornworms about. The plant is taking a chance. It invests in imperfect, but usually good, protection.

You may wonder how to compare hornworms that eat horsenettle tissue and those that do not. To what do you compare the ones that do? This is an interesting story. You can purchase little hornworms, special vials to grow them in, and hornworm chow. They do not naturally eat this chow, but if you start them on it when very young, they will eat it and grow grossly big. It is sort of hornworm junk food. The control worms are the ones that eat only the chow; the experimental worms have horsenettle tissue mixed in with the chow.

Herbivores, and the defenses of plants against them, are a constantly moving evolutionary target. They hardly ever get it right, but they come close enough that there are lots of plants, and lots of herbivores, in the world. Any plant that invested too much in defense would grow slowly and die; but if it invested too little, it would disappear down the gullets of extinction. There is a balance of nature, but it is imperfect and shifting.

A Deliberate Attack on Altruism

Altruism, within the human species, is where someone does something nice for another person with no calculated expectation of a reward for it. Of course, if there were never any rewards for people doing good deeds, this behavior pattern would never have evolved in humans. Everyone who does a good, altruistic deed at least hopes that he or she will receive some reward, directly or indirectly, but does not do a calculation in advance of the deed. There often isn’t any time for such a calculation. The calculation was done by natural selection in millions of years of our evolutionary ancestors, and today it is instinctual. In the past, doing good deeds was profitable. It remains so today.

But altruism is under attack in Texas. Everyone has heard about the Texas abortion law, which empowers anyone (not even a Texas resident) to sue anyone else whom they suspect, even if they cannot prove, of providing, or even “aiding or abetting,” an abortion in Texas. The Texas law establishes an inducement: the plaintiff can get $10,000. Suppose the defendant is innocent. The defendant has to prove his or her innocence in court, a lengthy process, and legal fees can be very expensive. The law specifies that the defendant cannot recover those fees, presumably even for a frivolous suit. Somebody can sue me because they claim that they think I helped someone get an abortion, even in the absence of evidence, and I am stuck with the time and expense of proving myself innocent.

The major thing about this law is not that it is about abortion. It is that the law takes a Texas aim at altruism. It incentivizes citizens to turn against fellow citizens for profit.

Political conservatives, especially gun-nuts, have long taken aim (literally?) at altruism. They promote a sign in which one neighbor proclaims that another neighbor does not have a gun. This amounts to inviting criminals to burglarize the gun-free house and perhaps to kill the owner. The gun-nut neighbor does not have the guts to go and kill his neighbor himself, so he puts up a sign inviting criminals to do the job for him. This is a totally blatant attack on the goodwill of one citizen for another. This is common enough of an occurrence that you can buy signs like this one on Amazon. I have searched, but found no indication, that this is a joke. Please, let it be a joke—but I fear it is not.

I thought it was against the law to incite one citizen to commit a crime against another citizen. Certainly if I put up signs urging people to kill Donald Trump, I would get in trouble for it. But this apparently does not apply to people who want to destroy all community goodwill and turn America into a madhouse of hatred.

As it turns out, the worst that people like me feared from the Texas abortion law has not yet come to pass. It was too extreme even for most conservatives, except for the legislators and governor who thought that Texans would all admire them for trying to destroy community goodwill. Apparently even most Texas Republicans do not want to see their state become a madhouse of hatred. There have, at the time of this writing, been only two lawsuits filed. One of them was from a disbarred Arkansas lawyer. As you might expect from a lawyer who breaks the law, he was allowed to sue for $10,000 so he sued for $100,000.

The intent of the law was to scare women away from having abortions in Texas, not because it is illegal, but because their facilitators would not be able to afford defending themselves against the lawsuits. It is, in fact, having this effect. This is now The Texas Way. Hey, pardner, we can use this approach for any conservative cause. So giddy up! What else can we do with this legal procedure?

Conservatives all over the country are foaming at the mouth at the fact that there are minority voters who do not share their white supremacist agenda. If an extremist right-wing state like Texas wanted to pass a law against minority voting, it would be quickly declared unconstitutional, even faster than they could wipe their butts with the constitution. But they could pass a law saying that anyone anywhere could file a suit against someone they suspect of voter fraud, and the defendant would have to pay the legal fees. It would take months to resolve the case. This is an easy and, if the Texas abortion law is any guide, legal way to keep minority voters away. Minority voters, rather than to face this kind of opposition that might send them into homelessness, will simply stay away from the polls where right-wing poll-watchers will take their pictures and download them directly onto litigation documents.

Minority voters could use this same law against white voters. I think that, in the court in which money rules, they would not be successful. But what if they were? What if organized minorities suppressed the white vote? That would just be one more example of what I am saying—that the Texas way promotes neighbor against neighbor, citizen against citizen, even if it is not necessarily an attack of conservatives or whites against others.

Could such a law actually work? We do not know. But it is impossible to not believe that the Texas legislature would be willing to give it a try. While there are lots of nice Texans—I know some—these nice Texans have absolutely no influence on their lawmakers, who are turning Texas into a medieval fortress of oppression. And there are plenty of pathogenic right-wingers who would be delighted to do the same in other states.

The only way I can be safe from lawsuit in Texas is to not go to Texas. I haven’t been there for a long time, and I will never go there again. I encourage all of you to also stay out of Texas. It ain’t a place for nice people.

This is supposed to be a science blog. This essay is about the science of altruism. But I really, really want to get back to writing about trees and stuff. Maybe this political craziness will slow down just long enough for me to do so. Fluff the Cottonwood Tree has another essay she wants me to post. I hope to do it soon.

This Is Starting to Get Crazy

 

Many of the Americans who oppose covid vaccination and mask mandates are fierce and even crazy. There has been nothing like it in medical history. Never before have so many people vehemently attacked medical science, at least not since Edward Jenner performed the first vaccination about 1800.

On Tuesday, September 28, a man in Wichita Falls, Texas, tried to enter a hospital without a mask. A security guard told him that the hospital required masks. The man became so angry that he attacked the guard and bit his thumb clear to the bone. You can read about it here from a local Texas newspaper.

This is beginning to look like a plague of insanity.

Greetings from Thumbelina

 

Some time ago, I posted a Darwin video about Thumbelina. This is a very old story, continually reappearing in new children’s books, about a young woman who is so small that she can hitch a ride on the back of a swallow or hide inside of a tulip (to use the two examples from our public library). We all know it is impossible to have a human being this small, but why is this so? 

Organisms can be very small. If you define an organism as something that can actively maintain constant internal conditions, and can reproduce itself, then the smallest organisms on Earth are bacteria and archaea. Viruses are smaller, but they cannot maintain constant internal conditions, or reproduce, by themselves; they have to outsource these processes to the cells that they parasitize. Astrobiologists (scientists who generate fact-based speculations about possible life on other planets) have lively disagreements about what the smallest life forms could be.

How small could a vertebrate be? A vertebrate is an animal that has (in addition to vertebrae) whole systems of organs that maintain constant internal conditions. Vertebrates are so complex that they could not possibly be microscopic.

But they can be pretty small. Scientists recently discovered a frog, Paedophryne amaneusis, that is so small that it can comfortably sit on a dime. X-rays reveal that it has a complete skeleton. It does not have a tadpole stage, but it attracts mates with ultrasonic peeps. I suspect that it does not need to have as much anatomical complexity to maintain internal conditions; for example, it probably absorbs most of the oxygen that it needs through its skin.

This image is from the source in this link.

Humans have seventy trillion cells. Would Thumbelina need to have seventy trillion very tiny cells? Probably not. She could have tiny organs that did everything that they needed to do, each organ with fewer and smaller cells.

But there is one organ that would need to have a minimum size: the brain. While Thumbelina could metabolize as she rode around on the back of a swallow, she would not be able to enjoy it, or even know what was happening. Since no one knows how to define consciousness, we cannot say how big a brain has to be to be conscious; but Thumbelina’s brain would definitely be too small.

Probably everyone has heard about the homunculus. This is supposedly a tiny complete person that lives inside of a sperm head, made famous by the Nicolaas Hartsoecker drawing (1695). According to many scientists of the late seventeenth century, that is where people came from: a little person inside a sperm grows up by consuming the food inside the egg. Some of the sperm had little men, some had little women, as in the drawing. Even more amazing, the male homunculi had sperm, with homunculi inside of them, with homunculi inside of them, with…how far can you go? Forever? Scientists at the time knew no reason to doubt it.

The reason that you cannot have an infinite regression of smaller and smaller objects is that everything is made of atoms. Although atoms are incredibly small, they are not infinitely small. This places a lower limit on the size of anything made out of atoms.

We must be careful to avoid the argument from incredulity: If I cannot believe it, then it cannot exist. Not long after I post this essay, a computer scientist might create a qubit structure that could fit inside Thumbelina’s head and impart a reasonable level of intelligence. But the principle remains unchanged: there is a lower limit of brain size for human intelligence, and Thumbelina is probably below that limit.

There are upper limits also. A very large walking vertebrate could not exist, since volume (weight) increases as the cube of the linear dimension while the strength of a leg increases only as the cross-sectional area (the square). An animal twice as big in linear dimensions would have legs four times as strong but would weigh eight times as much. This is true only for animals that walk on land. Whales can be much larger, but their weight is supported by the buoyant force of the water that they displace.

None of this will make any difference to people who are enjoying the new King Kong vs. Godzilla movie, or to my granddaughter who enjoys the Thumbelina books. But, I suspect, human imagination is limited—not by size, but by our evolutionary heritage. We imagine things that our evolved brains allow us to imagine, and nothing more.

 

Has the Pandemic Made Us Appreciate Science?

 

No.

One would think that the pandemic would have made Americans want to learn more about disease and health, about how to minimize the spread of disease by means of vaccination, social distancing, etc. In fact, this is what science writer Robin Marantz Henig said in the November 2020 issue of National Geographic: “Maybe the pandemic will persuade even the skeptics how crucial scientific discovery is to human flourishing.”

At the time Henig wrote this, it seemed so inescapably reasonable. But this has turned out to not be the case. The surge in covid cases in America, the great majority of them among the unvaccinated, has only strengthened the anti-science fervor among many Americans. About half of Americans disregard science, and many of these openly detest it. Rather than acknowledging that masks slow down the spread of covid, some states not only do not have mask mandates but have made these mandates illegal. Here in Oklahoma, it is illegal for schools and other state entities to require measures that protect either children or adults. It is difficult to appreciate the depth and scope of the hatred that many Americans feel toward science, whether it is the study of how diseases spread (epidemiology), or any other branch of science.

Right now, as shown in this graph from a French news website, America is leading the world in the number of covid deaths per day. Brazil used to be the leader, and Indonesia was briefly, but America has gone back to being the world leader in covid deaths per day.

As a science educator in rural Oklahoma, I feel quite despondent right now about the hostility of my neighbors toward any kind of scientific evidence about anything. I used to be inspired in my work; now, I just count the days to retirement.

Why Hasn't China Gone Green?

 

A special Labor Day essay!

China is the world’s biggest investor in and producer of green energy. Their participation in solar and wind energy is nothing short of breathtaking. They would seem to be a model to the rest of us of how an economy can go green.

They are, however, also the world’s biggest investor in and producer of dirty energy, in particular coal. In addition, they notoriously pollute the environments of their own billions of expendable citizens.

They are the best and the worst. What is going on here? May I speculate?

First, they know that green energy is the unavoidable path of the future. Civilization will collapse into a dark ages pile of wiggling failures if we do not embrace renewable, clean energy. They know this as much as anybody. They do not deny it, unlike the executives of American coal and oil corporations. Accordingly, China (led by its top-down imposition of economic priorities) leads the world in technological innovation of green energy. Someday, they are poised to lead the world.

Second, they also desire to bury the United States. I do not mean in a nuclear or violent way. But they want to bury us as a serious economic competitor. They plan to do this by out-producing us. They appear to be successful. They sell much much more to us than we sell to them. They will do this by using clean energy or dirty energy, whatever is at hand. Once they have buried us, they will be glad to switch to green energy, and at long last let their gasping, sick citizens breathe freely and let the skies become clear.

They are walking a tightrope, but they have done so many times before. They appear confident that they will lead the post-American world into a green energy future.

An Open Letter to the Governor of Oklahoma

In your delusions of defending the freedoms of Oklahomans, you and the legislature have guaranteed the absolute and inalienable rights of some Oklahomans to breathe coronaviruses into the faces of other Oklahomans. You have forbidden mask mandates in state agencies, such as the university where I work, and forbidden vaccination requirements. As a result, I am unable to defend myself from getting germs breathed in my face, and I cannot protect my students from having germs breathed into their faces, by a minority of Oklahomans who proudly refuse vaccination and refuse to wear masks. You have guaranteed that our current flood of covid cases will continue unabated. You must be proud of yourself for promoting the unnecessary sickness of thousands of Oklahomans.

Why don’t you go ahead and finish your work? Why stop with covid? There are other germs that can sicken Oklahomans. There are currently state laws that protect Oklahomans from exposure to these germs. Why don’t you strike down those state laws, and leave us even more vulnerable to contagious diseases? You have gone just partway in your blaze of conservative glory.

I refer in particular to salmonella. Some people are asymptomatic carriers of salmonella, and some of them work as food handlers. At the present time, salmonella outbreaks are rare because employees of food service providers are required by state law to wash their hands after using the restroom. This simple measure prevents infected food service workers from spreading the disease. But this state law, from your viewpoint, infringes on the fundamental freedom and dignity of food service workers by requiring them to wash their hands. Why don’t you eliminate this law? The deaths of a few hundred Oklahomans from salmonellosis is a small price to pay for the absolute freedom of food service workers to do whatever they want. Will you be a champion of freedom all the way, or only partway?

A disease that used to be common in America is typhoid fever. Like salmonella, it was spread from the unwashed hands of symptomless carriers to the people who eat the food they prepared. Frequently, the people who eat the food would die. The most famous of the symptomless carriers was a cook named Mary Mallon, now known as Typhoid Mary. Law enforcement caught her as she fled, and forbade her from ever again working as a cook. This was, of course, an infringement upon her American freedom. But they did it anyway. When she refused to stop working as a cook, she was imprisoned for the rest of her life.

But, today, in Oklahoma, according to the principles that you hold so dear, it would be illegal to prevent Typhoid Mary from working as a cook in a public school cafeteria. A school would be required to hire her if she was, in other ways, qualified for the job. The deaths of a few hundred schoolchildren would be, from your viewpoint, a small price to pay for Typhoid Mary’s freedom to choose whatever line of work she wishes.

Finally, there is a disease that was singlehandedly responsible for the deaths of about ten percent of people who have ever died in human history. That disease is smallpox. Through massive, often forced, vaccination of millions of people throughout the world (mostly Asia and Africa), a project led by the United Nations World Health Organization (of which you have a low opinion), this disease has now been eradicated. Nobody will ever again die of smallpox from natural transmission. There are still smallpox germs in freezers in the USA and Russia. We can only hope there are no bioterrorist groups that have the germs in their freezers. By your principles—that nobody should be forced to be vaccinated—smallpox would still be killing thousands if not millions of people.

And why is it okay to require measles vaccinations, but not covid vaccinations? Perhaps your crusade for freedom should expand to include the repeal of all vaccination requirements. Measles and mumps could then make a comeback for which you could claim the honor.

Schoolkids dying of measles, salmonella, and typhoid fever, and millions of people dying of smallpox—this is the kind of paradise that the world would be if it had followed your principles of “freedom.”