Apozygotic agamospermic apomictic agamospory

I'm making a table. Not the tisch, bord, tavolo, mensa kind. I'm making a table of comparisons of offspring viability between sexually and asexually produced offspring. This is polychallenging. Part of it is that the literature is scattered, so it takes a lot of hunting around, but that is a usual and interesting sort of challenge. Part of it is that I want to include lots of different kinds of organisms, and find basically comparable comparisons for each, and the measure one might use for offspring viability for a lizard is necessarily different than that used for an insect, plant or mold, but this is arises from the real diversity of biological process, and so is also interesting. The part that I am finding frustrating and difficult is the choking miasma of obfuscatory terminology. Some terms, like amictic, are used to mean different things by different authors. Clear concepts (e.g., what portion of seeds open and something live comes out) are referred to by a dozen different terms. Frequently a single author or group of authors will have a term that does not seem to be defined anywhere and isn't used by anyone else. Apozygotic, for example, seems to be used only by eastern European sugar beet scientists to mean agamospermic, which is a term botanists use to describe reproduction via diplospory, apospory or nucellar embryony, which are all (I think) non-automictic kinds of agamospory, which is close to what a zoologist would call apomictic parthenogenesis, which basically means that offspring are coming out of eggs (or seeds or spores) produced without any genetic recombination or changes in chromosome number along the way. There are various places in the literature or on the web where good intentions have tried to straighten all of this out and discard the duplicate or ambiguous terms, but of course they come to different conclusions and are frequently ignored.

Evolutionary biology vs. evolved biology

Once, during a medical exam, the doctor asked me what I did. I said I was an evolutionary biologist, to which he replied, "oh, so not a creation biologist?" His tone of voice made it clear he thought it was funny that I had to specify evolutionary, as though a biologist in Berkeley could possibly not believe in evolution. Considering where his hands were at the time, I didn't stop to explain to him what the term "evolutionary biologist" means. Every biologist knows, or should, that Theodosius Dobzhansky wrote, "Nothing in biology makes sense except in the light of evolution." The vast majority of biologists, of all disciplines not only know about evolution, but accept it as a necessary part of any complete explanation for the things they study. But a large portion of biologists don't regularly think about evolution; it is not the part of the explanation they are interested in. A large (and I think increasing) proportion of biologists study the interactions of atoms, molecules, organelles, genes, cells, etc. And while they may connect their work to evolution in some way, they are not basically asking questions about evolution, but about the details of the proximate mechanisms which make organisms work. That these mechanisms are the result of evolution is often not particularly relevant to the present question.

An example: A couple of years ago I attended a workshop on bioinformatics in aging research. There was a dinner the night before the talks started, and the bioinformaticist organizing the workshop asked me about my training and research. I said, "well I study the evolution of demographic patterns, particularly how constraints on natural selection lead observed demographic patterns to differ from the predictions of evolutionary theory." He replied, "Oh, but you are also trained in biology?" What he meant by this, I discovered, was that I also had some training in the molecular nuts and bolts that to him are biology. Evolution is a process that shapes biology, but in his view, and I think the view of many of the people there, does not in itself count as biology. Asking him if he ever incorporated evolution into his work, he explained that he had, comparing how networks of gene interactions differed between fruit fly and nematode. Fair enough, comparative biology is surely the study of evolution, but his approach to it required no technique or concept from evolutionary theory. He produces good and useful science, and gives no more daily thought to evolution than I give to promoter regions. I am certain that he would not be offended to be described as a good biologist who believes in evolution, but is not an evolutionary biologist.

A definition from wikipedia: "Evolutionary biology is a sub-field of biology concerned with the study of the evolutionary processes that have given rise to the diversity of life." This is somewhat too narrow in my view, but it is close enough given that it is past my bedtime.

This has all come to mind because of the post I wrote yesterday, about weeds evolving resistance to Monsanto's best-selling herbicide, and the failure of Monsanto's biologists to predict this. A good friend of mine, who is deeply knowledgeable about matters environmental and agricultural, responded by asking how Monsanto's biologists could have failed to predict the apparently obvious facts I was pointing out unless they were A, Tools; B, Fools; or C, having their results manipulated by suits. This is a reasonable and interesting question, and I'll venture an answer. My guess is that they were neither A nor B, and that C went on but was not a major factor. Monsanto did have an enormous financial stake in convincing regulators that weeds would not evolve resistance to Roundup, but they also had an enormous stake in having weeds actually not evolve resistance to Roundup.  So my guess is they honestly thought it was a highly unlikely outcome.

Why did they think so, despite being smart, honest biologists? Because they weren't trained in, or primarily thinking about, evolution as it occurs in nature. They were plant geneticist and bioengineers, spending many years and countless millions of dollars to unravel the finest details of how Roundup kills plants and how to build a crop that will have resistance to it (without passing that resistance on to its offspring). That was an enormous challenge, and their success was unprecedented. They had achieved what many, even within their own company, must have thought was an impossible SciFi dream.

Surely someone was assigned to think deeply about the problem of whether weeds would evolve resistance, but surely that someone had been involved in the project for years, and was so wrapped up in the grotesque details of the genetic magic they had just achieved that no perspective was possible. In other words, they couldn't see the field for the soybeans. A person highly trained in artificial selection, and used to that way of thinking, will think of the evolution of weed resistance in those terms, despite the fact that natural selection has inherent advantages.

In hindsight, their logical errors are obvious, probably even to them. In foresight, reasonable and well intentioned people frequently fail to think of highly relevant and potentially obvious things. This is particularly likely if those things require a perspective they don't possess, doubly particularly if they are thinking deeply about the problem from a very different perspective. Monsanto had many biologists who knew about evolution, used a particular type of evolution as a tool, and thought about evolution. But my guess is they didn't have any evolutionary biologists.

Evolution infringes upon Monsanto's patent

NPR has a useful story today by a guy who interviewed people who were involved in Monsanto's application for release, in 1993, of "Roundup Ready" crops, that is crops that are genetically engineered to be resistant to Monsanto's best selling herbicide, glyphosate, sold as Roundup. The idea, which has made Monsanto many billions of dollars, is that if the crops are immune to the herbicide, and weeds are not, fields can be sprayed liberally. Farmers don't have to do mechanical weeding, and Monsanto gets to sell them both the patented herbicide and the patented resistant seed. This set of facts, along with Monsanto acting like the faceless corporate giant that it is in defending its patents, has made it probably the most despised company among the organic farming crowd, vilified far more than competitors like ADM or DuPont.

The point of the article is that Monsanto falsely rejected the possibility that carpeting the world in Roundup would lead to the evolution of Roundup resistant weeds.

Then the story, written by Daniel Charles, continues like so:

Oops. Since then, resistance to glyphosate has emerged in 20 different weed species.
  I called up several people who were at Monsanto at that time. Why didn't people there think resistance would happen? They all told a similar story.
First, the company had been selling Roundup for years without any problems. Second, and perhaps most important, the company's scientists had just spent more than a decade, and many millions of dollars, trying to create the Roundup-resistant plants that they desperately wanted — soybeans and cotton and corn. It had been incredibly difficult. When I interviewed former Monsanto scientists for my book on biotech crops, one of them called it the company's "Manhattan Project."
Considering how hard it had been to create those crops, "the thinking was, it would be really difficult for weeds to become tolerant" to Roundup, says Rick Cole, who is now responsible for Monsanto's efforts to deal with the problem of resistant weeds.

In case the holes in their logic haven't struck you, allow me to provide a quick lesson in how natural selection (or in this case semi-natural selection), as opposed to genetic engineering, works.

Engineers at Monsanto were surely aware of natural selection and its proclivity to producing resistant pests, but they considered the idea that there would be even a hint of heritable resistance in the weed populations to be highly unlikely. This is because they failed to consider the following facts:

A. They were testing thousands of highly targeted potential genetic alterations in the lab, on a few crop species, and found that almost none of them conferred significant resistance. They didn't consider that after global distribution of their crops, trillions of genetically distinct (although totally untargetted) genetic modifications (that is, natural mutations) in thousands of weed species would be tested for their resistance. When something potentially useful did pop up, Monsanto was again able to test hundreds or maybe thousands of slight modifications on that, while natural selection could within a few years test millions of potential modifications iteratively over several generations. So they didn't consider that nature's search for solutions would be far more exhaustive than theirs.

B. I'm sure engineers have a term for closely examining one type of failure risk while completely ignoring others. That's what Monsanto did. They were look hard at making plant tissue resistant.  From the same story:

Some weeds, Cole says, appear to keep glyphosate from entering the plant at all; others sequester the herbicide in a spot where it can't do much damage. Monsanto's genetically engineered crops use a different technique entirely.

So they didn't consider the possibility that some plants would simply shield their vital tissues from the toxin, the way many metal resistant plants do.

C. They assumed that because Roundup had been used broadly for several years already, and there were no known resistant weeds, weed populations simply had no resistance traits available for natural selection to favor. They failed to consider that with the introduction of their crops, and the resulting increase in usage, both the population size of the exposed weeds and the force of selection for resistance would increase dramatically.

The force of selection is a measure biologists use to ask the question, how much difference does a heritable change of a certain size in a trait (for example a 0.1% increase the probability of surviving a spraying with Roundup) make to the fitness of the individuals with that altered trait. So long as most individuals in a weed population were never exposed to Roundup, the force of selection for resistance to it was small. Resistance doesn't help much if you are never exposed. The seeds blowing into farmers fields were coming from unexposed sub-populations, and so were not resistant. When we started blanketing the world in Roundup, the force of selection increased, because most every weed subpopulation over huge areas was exposed. So their experience up to that point led them to underestimated the force of selection for resistance. And if there is one thing that evil empires should know, it is to never underestimate the force.

A botanist once told me...

"Sedges have edges, rushes are round, and grasses, like asses, have holes."

Botanists have to make up dirty rhymes because they can't just take fecal samples the way zoologists do.

Kudzu Power

For several years I've mused that if only we could find some efficient way to make ethanol from Kudzu (the incredibly fast growing invasive weed that has taken over much of the southeastern US), we could stop importing petroleum, vastly improve many ecosystems and tremendously improve the US economy, all in one swell foop. I didn't take this idea very seriously. It appears that somebody else has. Consider the following abstract from a recent volume of the journal Biomass and Bioenergy:

We determined the amount of standing biomass of kudzu (Pueraria montana var lobata) in naturally infested fields in Maryland and Alabama, USA. At each site, we evaluated the carbohydrate content of roots, stems, and leaves. For a third site from Georgia, we evaluated the carbohydrate content of kudzu roots of varying diameters. Belowground biomass in Alabama exceeded 13 t ha⁻¹, and contained an average of 37% fermentable carbohydrates (sucrose, glucose, and starch). Roots from Georgia of all size classes contained over 60% fermentable carbohydrates. Biomass and carbohydrate levels in roots from Maryland were low compared to plants growing in Alabama and Georgia, producing 5 t ha⁻¹ of roots with 20% non-structural carbohydrate. Stems from Alabama and Maryland contained 1–3% carbohydrates. Based on the yield and carbohydrate content, we estimate wild kudzu stands in Alabama and Georgia could produce 5–10 t ha⁻¹ of carbohydrate, which would rival carbohydrate production from maize and sugar cane fields. If economical harvesting and processing techniques could be developed, the kudzu infesting North America has the potential to supplement existing bioethanol feedstocks, which could be of significance to the rural economy of the southeastern USA.

Further consider this economical processing technique, from next month's PNAS:

Abundant plant biomass has the potential to become a sustainable source of fuels and chemicals. Realizing this potential requires the economical conversion of recalcitrant lignocellulose into useful intermediates, such as sugars. We report a high-yielding chemical process for the hydrolysis of biomass into monosaccharides. Adding water gradually to a chloride ionic liquid-containing catalytic acid leads to a nearly 90% yield of glucose from cellulose and 70–80% yield of sugars from untreated corn stover. Ion-exclusion chromatography allows recovery of the ionic liquid and delivers sugar feedstocks that support the vigorous growth of ethanologenic microbes. This simple chemical process, which requires neither an edible plant nor a cellulase, could enable crude biomass to be the sole source of carbon for a scalable biorefinery.

This will, of course, take longer and be more complicated than anyone currently expects, but I'd be surprised if we don't eventually have industrial scale application of this technology, using many sources, including kudzu.

Plant Behavior

There is a scientific society dedicated to the study of almost anything. But until recently (2005) there was no society dedicated to the study of the behaviors of plants. Enter The Society of Plant Neurobiology. which states on its website:

"Plant Neurobiology describes a newly named, but also old and fascinating field in plant biology addressing the physiological basis of adaptive behavior in plants. Perhaps this field could be called "Sensory Biology in Plants" or something similar. However, these names don't quite cover topics like plant cytology and anatomy, adaptive plant behavior, signaling and communication in symbiosis and pathogenesis, or newly emerging topics like for instance plant immunity, plant memory and learning, plant-plant communication, as well as plant intelligence."

This is very convenient for me, as I am currently writing a paper on, among other things, taxonomic bias in definitions of the word 'behavior.' Having gotten input from member of the Animal Behavior Society and the International Society for Applied Ethology, I am thrilled to be able to get the viewpoints of botanists interested in behavior. I emailed the chair of their steering committee, asking her to forward a link to my "what is behavior?" survey to their membership. If she is sympathetic, this could be really cool.

I learned of the existence of SPNb through this article on NYTImes.com. Check out the video of the parasitic plant sniffing for prey and pouncing on the unsuspecting tomato vine.