Field of Science

Most successful plant in the world

People call universities to find things out that aren't easily looked up, and for many years all the weird plant related questions have been forwarded to me. I'd like to think it was because of my success at answering such questions, as opposed my being weird. So it was not a surprise when my phone rang recently and someone wanted to know, for an article they were writing, what was the most successful plant in the world?

Now that's an interesting question because it can be answered from several different perspectives depending upon how you define success.

My first idea was that the most successful plant in the world was one of the domesticated grasses, a cereal grain. From its beginning as a wild middle eastern grass wheat has become the most commonly cultivated plant in the world. But rice provides the majority of calories to the majority of the world's people. And altogether cereal grains occupy something like 70% of all tillable land.
Now such plants are successful because they were useful and important to humans. Cereal grains have moved with us and native plant communities removed for the culture of these cereals, and in a manner of speaking cereal grains have become immensely successful. But without human intervention, they would not long persist in such vast areas.

And of course there are weeds. Weeds are adapted to disturbance, so they grow rapidly reproduce quickly, in great numbers, and then disperse widely. You probably didn't need to be told that, but now you know why. Nature produces disturbances, so weeds occur naturally to take advantage of these sites. But the thing that humans do best, and most frequently and thoroughly, is create disturbance, so weeds have greatly benefited by human activities. Agriculture can be defined as a systematic disturbance of natural communities for the purpose of growing domesticated plants and animals. So weeds have greatly prospered and gained great success as a result of human activities too, but they have done it on their own. No wonder such successful plants are so hard to eradicate.

Another concept of successful is longevity. Some aspen or sagebrush clones appear to be 10,000 years old, and that's a long time for one individual to exist. Some bristlecone pines are known to be over 7,000 years old. Such long-lived organisms are certainly successful. Osmunda cinnamomea, the cinnamon fern, certainly is a longevity contender too. 70 million year old fossils of this fern have been found that are virtually identical to the living species. This makes this fern the oldest known species, period, plant or otherwise. I have a fossil fern stem from the Carboniferous era over 300 million years ago that is anatomically identical with modern Osmunda ferns. So the group has been around for a long, long time. Selaginella, a clubmoss, is another genus with a very long history dating to the early Carboniferous, and that makes it the oldest living genus.

If you take a broad definition of plant, then perhaps a particular cyanobacterium (sometimes called blue-green algae), like this one pictured here on the right, might be considered the most successful and influential plant in the entire of Earth history. Sometime 2 to 2.5 or so billion years ago this cyanobacterium became a chloroplast giving rise to all of the other green organisms. When you look outside your window you see green because this incredibly tiny green cell, now functioning as a cellular component in all plants, has been duplicated in countless numbers. Cyanobacteria, including chloroplasts, are the only organisms that use water in photosynthesis for a hydrogen source, which leaves oxygen as a by-product. All of the oxygen that makes up 20% of Earth's atmosphere (and its ozone layer) is a by-product of photosynthesis. Talk about influential! This changed Earth history completely. Aerobic organisms such as ourselves were not possible until there was oxygen in the atmosphere. So in terms of sheer number, ubiquity, and influence, the cyanobacterium that became a chloroplast is probably the most successful green organism in the entire of Earth history. But we are probably wrong to call it a plant.

So there you have it. Depending upon the type of success you were looking for, those are the most successful plants.

The trouble with trying to get religious students to think

The American Center for Law and Justice recently claimed to have championed the rights of a religious student who was being persecuted by professor.

But the Center for Inquiry has another version of the story. The American Center for Law and Justice (ACLJ) has recently boasted of a "victory" in protecting a college student's rights to religious freedom. In postings on its website and in a radio broadcast on June 4, 2008, the ACLJ has trumpeted the claim that a demand letter one of its staff attorneys sent to Suffolk County Community College prevented a Christian student from receiving a failing grade from a professor who wanted to penalize her because of her religious beliefs.

The CfI says nothing could be further from the truth. "The ACLJ's spurious claim of a legal 'victory' is just slightly less outrageous than its brazen attempt to intimidate a philosophy professor from doing his job—which is to get students to think critically," commented Ronald A. Lindsay, Executive Director of the Council of Secular Humanism, who has talked to the allegedly biased professor. "As far as I can tell," observed Lindsay, "the ACLJ's letter accomplished nothing other than providing an excuse for soliciting donations."

The scholar that the ACLJ falsely accused of bias is a longtime philosophy professor who has taught more than 13,000 students over a period of thirty-six years. He has a well-deserved reputation for fairness, and has served as President of the American Association of Philosophy Teachers and as an officer in many other organizations. Although the ACLJ's radio broadcast alleged that the professor "hates" the very idea of Christians, this professor has taught students of many different faiths, and no faith, over the years, all without incident until the ACLJ's campaign of vilification. Indeed, after the ACLJ made its baseless accusations, students in this professor's philosophy class, including religious students, defended him, stating that he does not pass judgment on students because of their beliefs, but simply challenges them to examine all beliefs critically, including their own. His students have stated that they cannot identify the professor's own views based either on the course materials or the textbook authored for the class by the professor, and he does not pressure them to adopt any particular position.
"I would not be doing my job as a philosophy professor," explained the professor, "if I did not require students to think about their beliefs and provide reasons in support of their beliefs— not my beliefs or anyone else's beliefs. Critical examination of beliefs, including one's own beliefs, and training in reasoning are among the primary objectives of a philosophy course, and of a liberal education in general. Only professors who are negligent or indifferent allow students to earn good grades simply by providing as a reason for an assertion 'well, this is what I believe'."
The professor will not discuss in detail his interaction with the student who complained to the ACLJ about him, because he does not believe it is appropriate to share the details of a student's coursework with the outside world. However, he does have a right to defend himself against false accusations. The core of the ACLJ's claim is that the student was in danger of failing the class because of the professor's religious bias before the ACLJ intervened. "That claim is preposterous," according to Pecorino. "At no time did I tell her she was in danger of failing. When I had to project a grade for her earlier in the semester, I projected a 'C' and that was when she was most resistant to providing any reasoning to support her assertions. She was not open to examining her own beliefs or to entering into the dialectical process of inquiry in community because, according to her, she already had all the answers." And what of the ACLJ's claim that the student had a failing grade average of 54 prior to the ACLJ's intervention? "That is a misleading use of information. I use a cumulative point system in grading," explained the professor. "In other words, as students progress during the semester, they earn points for each assignment, with a possible total of 100 points by the end of the semester. She at one point probably did have 54 points, but that in no way indicates she was in danger of failing. She had 54 points, not a failing grade average of 54. All students start the semester with 0 points, so by the ACLJ's logic, all students are in danger of failing."

And did the ACLJ's letter influence the professor, either directly or indirectly through pressure from college administrators? "Absolutely not," the professor states. "I received no pressure form my college administrators, only support, and although I was a bit bothered by all the hate emails and other communications that resulted from the ACLJ's campaign against me, I did not let that affect my grading of this student. I take my responsibilities as an educator too seriously for that to happen. The student received a 'B' because she earned a 'B,' no more and no less."
The ACLJ's campaign against this professor cannot be dismissed as insignificant. As the professor observes, "Essentially, the ACLJ is claiming a religious exemption from the obligation of students in public colleges to engage in critical thinking, and this claim strikes at the core of higher education. If permitted to go unchallenged, this claim will weaken our democratic and pluralistic society." Lindsay agrees, adding, "For a democracy to succeed, we need citizens who can provide reasons to support their beliefs. We cannot reason together if all we have are groups of individuals who adamantly insist they have all the answers because of some supernatural revelation and who are unwilling to consider opposing viewpoints. The ACLJ is a very slick, very well-funded organization, and its animosity toward critical thinking is even more troubling than its willingness to distort the facts."

We’ve all had students like this. Only a couple of years ago I had a student in a senior seminar class, a “capstone experience” for biology majors who refused to discuss or even justify their positions or opinions. I had “no right to pass judgment”. Of course I wasn’t passing judgment, I was trying to get students to think and support their positions in a manner scientific. Now that was the catch. It just doesn’t cut much mustard to tell me that human life begins at the moment of conception because the Bible says so (and it doesn’t). Their complaint about my bias against their religious perspective went no further than a dean of undergraduate studies who decided is was perfectly OK that a professor of science would ask science majors to justify positions in a scientific manner. Even then I was not requiring anyone to argue for any particular positions, but interestingly enough, all of the biology majors changed their initial ideas about the beginning of human life, not all in the same way, as they learned more, thought more, and gained more knowledge. Only one student dogmatically stuck to their initial position no matter what; they remained unfazed by new information and new ideas. And if such people are actually model citizens, then demoncracy is indeed in trouble should they ever gain a majority.

And it again brings up the idea that I have blogged about before that religious thinking interferes with learning. I was greatly relieved to learn that this student was not a biology major, but had gotten into the class via some strange non-major major. After this experience I investigated this non-major major and ultimately was instrumental in killing this academic monster.

Of course in this specific instance the Catholic Church jumped on the idea of conception as the beginning of human life because of they wanted a fixed point at which to say an individual with a soul existed. The logical inconsistencies that have arisen as science has moved on are causing all manner of problems unless the faithful just continue to believe. Religion and science may coexist, but dogmatism and science can never coexist.

Field work - snapshots in ecological time

Only other field biologists can appreciate and sympathize with this problem. Studies done in the field cannot control for all the variations in nature, in particular normal variations in weather patterns, and so each study is actually a snapshot in ecological time. The trouble is that we try to extrapolate from these snapshots, and sometimes that doesn't work. And even worse you worry that the effects of weather can overwhelm your treatments.

The effort involved in field work makes the situation even worse. The steadfast effort involved in maintaining long term field studies is beyond most of us. For this reason I really admire Deborah and David Clark whose quarter century survey of tropical forest tree growth in Costa Rica is laudable just for its longevity, its contribution to understanding changes that may accompany global warming notwithstanding (Tropical rain forest tree growth and atmospheric
carbon dynamics linked to interannual temperature variation during 1984–2000. D. A. Clark, S. C. Piper, C. D. Keeling, and D. B. Clark. 2003. PNAS 100:5852-5857
.). If you haven't read this paper and want to see good evidence of changes that accompany increases in carbon dioxide and temperature, I recommend it.

In just the 3d year of our field study on the effects of hemiparasitic plants on the prairie community, and already the year to year variation seems destined to swamp any treatment effects. Last year our plots had so many hemiparasite seedlings that we wondered if eradication was a feasible treatment. They just kept sprouting, and we just kept weeding. Those seeds were the product of the 2006 season. The spring of 2008 was very different. It was cold and wet, and this affected the number and/or activities of bumblebees because seeds of our hemiparasite are scarce even though it flowered like crazy. Last year I could collect seeds in huge numbers, nearly 250,000 in about 20 mins. But this year a similar investment in collecting produced a very small volume in comparison. Guess we won't have so many seedlings to remove next year.

But that's not all. Last year produced a bumper crop of seeds, but so far they have not been germinating like last year at all. In 2007 we could find hundreds per square meter, and this year when we decide to monitor seedling mortality, seedlings are hard to find. It makes for easier eradication, but is messing with out demographic study.

That's just how field work goes. And it's why those rare long term studies are so valuable. If we monitored pollination, and seed production, and seed germination for 25 or so years, we would probably understand many of the variables. But when something gives you a significant result, well, dang, you just know it's important and real because everything was working against you getting any results at all.

Biological significance of political boundaries

About a dozen years ago after returning from a couple of months of tropical field work I though wouldn't it be a really great idea to get some of our students out of the familiar agro-urban environments of Lincolnland and teach them about tropical rain forest first hand. This has been a most successful endeavor, although not without having been a gigantic pain at times in terms of logistics, red tape, and other non-educational factors.

Although things had gone along well enough, it was long since past time to have this highly successful education endeavor recognized as a formal course offering. Now any good academic knows what a huge amount of hassle is involved with proposing a new course, even one that has been taught annually, successfully, via a loophole. But still the arguments were strong, and the track record good. So you can imagine my surprise to receive the following question posed by a curriculum committee whose collective intelligence is now exposed as a inconceiveably low.

"How can you justify to the tax payers of Lincolnland your use of limited resources to take students on a tour of tropical rain forest in some Central American country?"

Wow! Such a sheer naked exposition of ignorance has a way of taking my breath away. But the chair of the committee assured me this was a serious question and approval could hang in the balance depending upon the eloquence of my response.

I did my best. I cannot for the life of me think of one single way in which the arbitrary political boundaries of our particular tribe have any bearing upon the biology of organisms, the interrelated web of life, the truly global knowledge that is biology. True, political boundaries do play a great role in making the study of biology and the travel of biologists and their students a trying and more difficult task, what with all their rules and regulations. You see there just isn't a Lincolnland biology, or a 'Mercan" biology, either. There is one biology. The effects of tropical deforestation will not have to apply for a visa or seek papers from the Lincolnland bureaucracy.

I cannot help but wonder what the questioners might think are justifiable topics to teach students in our particular kingdom? Do members of this committee who have approved all manner of "tours" and study abroad courses think rain forest biology less relevant to biology majors than European history or foreign language is to humanities majors? Can well-educated academics actually be so ignorant, so scientifically illiterate? So I am dealing with people who only know human cultural artifacts as matters of significance. Imagine what this committee demands of astronomers! What do you mean our state isn't the exact center of the Universe?

And we take our students on a field trip, during which I am an instructor, an educator. There is a single destination, the class goes there and learns tropical biology through instruction and investigation. I'm not a tour guide and the class is not on a tour. While I know this type of superficial travel is the norm in the humanities, it isn't how we do business in biology. Of course, some institutions do take their biology students on tours, and some have stopped by the particular field station where our field trip takes place. They come, they go, and still my class investigates, studies, and learns. And while the "tour guides" rush around with all the logistics, us instructors, provide direction, send our troops out to learn, while we sit on the veranda drinking excellent coffee and watch the tours pack their gear. The difference between a field trip and a tour are very profound. Want to bet which participants learn more?

Of course our official purpose is to "train people for the work force of Lincolnland". So just by educating students, I'm failing to fulfill my duty to the taxpayers "train". Sit up! Speak! What's one more transgression?

Then there is the truly amazing fact that the students themselves pay for this educational experience in the tropics. The taxpayers aren't supporting this in any direct, substantive means at all. I'd better get a junior colleague to write the response because I'm not sure I can do it without tearing their heads off!