We are all family!

Dear Students,

This week in science ten we were discussing adaptations and speciation. What constitutes a species is one of those messy areas in biology. A species is defined as a group of related organisms that interbreed with each other. The definition is relatively straightforward, but given how evolution occurs the boundaries are going to be fuzzy.

An example of the problem is a ring species such as the Laras gull. These gulls exist as separate geographical populations, and each can interbreed with its neighbour.

Gull A can interbreed with Gull B which can interbreed with Gull C which can interbreed with Gull D which can interbreed with Gull E. These are stable populations, and you might expect that they are all the same species, except that Gull E cannot breed with Gull A.

Yah. The first time I understood what that meant my head exploded just a little bit. We often think of our evolutionary lineage extending back to a common ape-like ancestor, with some sort of 'missing link'. Except, if you understand evolution, you understand that species are not separated by discrete 'links', but by slight variation. This makes a bit more sense if you think of following your family tree backwards. First you meet your parents, then your grandparents, then your great-grandparents, great-great-grandparents, and so on. Richard Dawkins suggests that if you go back approximately 250,000 greats you'll meet the common ancestor for chimps, bonobos and humans. Every step of that journey, meeting each one of your ancestors, there were none that would be considered a separate species from those immediately before or after. Yet the difference between the beginning and the end is that of a different species. There's sometimes a misconception within popular culture that a new species arises when a baby is born that has significantly new abilities from its parents, and that needn't be the case. Each birth is a tiny step in a journey, and it's only when comparing the end points that the label of differing 'species' makes sense. While with the gulls the difference is one of genes and geography, with chimps and humans is one of genes and time.

There are species today in which this blurring of boundaries can still be seen. Donkeys and horses can breed and the offspring will either be a mule or a hinny. Donkey's and horses are close enough to interbreed, but it's still not quite close enough. Mules and hinnys are often sterile. The number of chromosomes in each species is different; donkeys have 62, and horses 64. This gives the mule 63, and the odd number usually prevents meiosis, which in turn causes sterility. Ligors and tigons are another example.

Which, of course, brings up Oliver, the Humanzee or Chuman. Oliver is a chimpanzee that prefers to walk on two feet, and his physical appearances seemed to suggest a more human 'look' than was normal for chimpanzee's. Oliver also apparently like human females more than chimpanzee females. Naturally there has been speculation that he is a cross between a human and a chimpanzee. Since 94% of human and chimp DNA is identical, although chimpanzee's and humans share the same chromosome problem as donkey's and horses; humans have 46 and chimps have 48. This difference occurred as what is called chromosome 2 in humans is fused homologous version of 2 chromosomes in chimps. This piece of evidence for common ancestry played a small role in the Kitzmiller v. Dover case in the United States where creationists cdesign proponentsists tried to add religious views to the science classroom.

So what about Oliver? Is he chimp, or is he something in between? Given the differences in chromosomes, it was not difficult to test this hypothesis. If chimps have 48 chromosomes, and humans have 46, then a confirmation of 47 chromosomes in Oliver would confirm his humanzee status. This test was performed, and Oliver has 48 chromosomes, and remains a cousin rather than a brother.

This example suggests the impact evolution is having on our society. Where we once saw species as separate and distinct, we now see them as continuous and related. Where humans were once considered the pinnacle of design, we are now just one twig of a giant tree, members of an enormous family. The science has been clear for a long time (150 years!), but it takes time for the meaning to permeate philosophy and culture. The excitement over Oliver is a reflection of our growing understanding that we are all, in fact, related.

Cheers,

Ron Neufeld
Canada's Best Boarding School

Update : Some students asked if there was a difference between a tigon and a ligor, or a humanzee or chuman. There is. Offspring of two different species have the name of the male species for the first half, and the name of the female species for the second half. So a 'tigon' is the result of a male tiger and a female lion. (Our culture has patriarchal roots, and I presume the 'male first' rule extends from this older cultural expectation.)

The Changing Nature of the Classroom

Dear Students,

This week I had a former student drop in to say hi. In the course of the conversation I asked about university, and how we could prepare our students even better.

Disclaimer: Naturally this does not reflect every (or necessarily even most) universities, and may be coloured by the student (although he did go online and show me his courses so I have confirmed wherever possible).

In class, as a teacher, I have been guilty on more than one occasion of using scare tactics. Since our school's entire purpose is aimed at getting students into the university of their choice, I have often commented what university professors will (and especially will not) accept, and how uncaring many will seem. We care about your progress. If you do not do an assignment, you'll hear about it and (since we're a boarding school) we know where you live. There is no escape.

In university nobody will notice when you don't hand in an assignment. This much I remember from my own experiences, and as far as I can tell not much has changed. However, now it is apparently possible not to even know you have assignments!

The student, who attends a major Canadian university, was quite surprised to discover a few weeks into his courses that all course information was online. Quizzes and assignments are scheduled online, assignments are handed in online, and it is impossible to hand in an assignment on paper. Even some exams and mid-terms are online (and unsupervised). With no deadlines announced in class, unplugging for a day is no longer an option. By 'surprised', I mean a quiz had been posted and taken down, all without a single mention in class. Students who noticed got the chance to complete it. Those who didn't did not.

Class may consist of a PowerPoint presentation in which you've downloaded the material before class, and you're filling in the notes as the professor lectures. Some people apparently get really good at Tetris, and take the time to manage their social calendar on Facebook instead. The classroom is filled with laptops.

This is a bit different. You're expected to exercise more responsibility, but also have more opportunities to become distracted. Like most changes it comes with its advantages and disadvantages. I think I would have loved it as the ability to get the notes any time, and the online nature of assignments and quizzes would have kept me organized. The ability to surf when the teacher gets boring? That would probably take a bit more getting used to.

I have already started increasing the resources available outside of class, and have taught all of my students how to hand in assignments and take quizzes or tests online. With classroom laptops, however, I would want a management system. Software installed on each student's computer that would allow me to see what every student was doing, and take control or shut down the computer as necessary. University may be the place for increased personal responsibility, but I care far too much as to whether or not you're understanding the material to allow students that much distraction without a way to return you to task.

I'm curious to know what students think. Some have already started bringing a laptop to class. I haven't banned laptops, as some teachers are wont to do, as I do recognize the potential and the numbers are not high enough to worry about. As numbers increase, however, I will eventually be forced to either ban the laptop and force you to use dead trees to write on, or I will insist you install classroom management software on your laptop in order to have it in class.

Knowing your teacher could take control of your laptop at any point seems a little creepy, although the program would be under your control. Outside of class you simply wouldn't start the program, but inside the class it would be running in order to have the privilege of having your laptop out. Would it be worth it? Let me know.

Cheers,

Ron Neufeld
Canada's Best Boarding School

The Truth about Vaccines

Dear Students,

I was up at the Pharmasave today, and a stack of books for sale caught my eye. "The Truth about Vaccines" it exclaimed, while showing a happy elderly couple. Smaller print suggested "Natural alternatives to Vaccines", "Side Effects of Vaccines", and how to boost your immune system.

Here's the actual truth about vaccines. When your body is attacked by an invader, not only does your body mobilize B-Cells and T-Cells to fight the infection, it also creates memory cells that stick around and are primed to react very quickly if the same trigger (called an antigen) ever dares to show up again. Vaccines work by giving a weak or dead antigen to trick the immune system into creating these memory cells, and voila! You are now resistant to a disease that might otherwise have killed you. (See here for a quick overview in cartoon form.)

There are a few other truths. Like failing to vaccinate your children may kill them. Why people believe otherwise, and the pseudoscience involved, may be a possible research topic for a future class.

There are a couple of possible focus points, but the most recent is such a perfect example of the importance of conducting science ethically and honestly. The researcher that started the whole vaccine denier mess? It turns out he may have actually faked the data to begin with!

The world is a dangerous place. Science reveals the danger signs. Luckily some places may be waking up to the danger.

It would seem, however, that when it comes to medicine that our provincial government may also be edging into a non-science approach to medicine. Naturopaths may soon be allowed to prescribe medication! Some of the information in the article is interesting for what it is trying to imply. Naturopathic practicioners have a regulatory College, they call themselves physicians, and take both undergraduate and graduate science courses. Does this make them science-based? Of course not. What's the harm? Check for yourself here.

In one class we've been discussing the difference between real science, and people that try to fake a science, using intelligent design as an example. Those of you reflecting in your journals as to how to tell the difference, naturopathy would be a great topic to investigate.

Cheers,

Ron Neufeld
Canada's Best Boarding School

Happy Darwin Day!

Happy Darwin Day!

(Click to embiggen.)

Via http://www.wordle.net/, it's the text of Darwin's classic On the Origin of Species, with the words that appear most often scaled to appear equivalently larger.

Teh Intertubes. Is there anything it can't do?

Cheers,

Ron Neufeld
Canada's Best Boarding School

Links for Darwin Day :

Six-minute Tree of Life video that appeared on the BBC One programme 'Charles Darwin and the Tree of Life' narrated by David Attenborough.

Darwin Day Celebration

Heat the Hornet by Richard Dawkins

Nature has some great podcasts on Darwin.

A virtual Evolution Lab (it's sorta like a game...)

Biomorphs!

This isn't evolution, but it looks like a cool version of evolution.

Updates of student suggested links:

Darwin on Wikipedia

The Darwin Awards (of course)

Devolve Me - see what you'd look like as an early human!

A's for everyone!

Dear Students,

Via the Blog Pharyngula (unlinked as the blog is occasionally NSFS), although here is the original Globe & Mail article.

University of Ottawa professor Denis Rancourt is in a spot of trouble. To quote:

“Grades poison the educational environment,” he insists. “We're training students to be obedient, and to try to read our minds, rather than being a catalyst for learning.”

More to the point, he's given all his students an A+. At the beginning of the course. And not in some sort of soft course like art appreciation, but physics! The university is naturally peeved, and at one point had him escorted off campus in handcuffs. Leaving aside the issues of academic freedom, the story does illustrate rather well the love/hate relationship teachers have with grades.

There is the obvious point, in that I don't want to be operated on by a doctor that hasn't had his skills measured or verified in some way. Grades, however, can certainly be an impediment to learning. Students can focus on the mark, trying to figure out how to raise their score, ignoring the broader context of what the course is about. Students who can name the structures of the lung, but cannot answer why the body needs oxygen would be an example. As a teacher it can also be used as a stick, forcing students to complete work not because they find it useful to learn the material, but because I think the task is required for understanding. There is no question some students would stop trying if an 'A+' was already granted. There is also no question that some students stop trying because the grades they get are discouraging. And really, is someone who got an 'A' on a course but can't remember any different? I find the hard-working student in Chemistry 11, whether they got a 'C+' or an 'A', is usually more prepared for Chemistry 12 than the naturally brilliant 'A' student. Universities and professional programs often just expect you have the knowledge and (once accepted) don't really care what you previous grades were. You just better know it.

I don't have an answer to this. As much as I admire the professor's chutzpah, and disapprove of the university's tactics (if you can't try cutting edge teaching experiments in university, where are they going to be tried?), I suspect some form of evaluation will always be with us. At some point, at some point, the engineer or the doctor is going to have to prove they know what they need to know.

But what do you think? Would you work in a course in which you already had the highest mark possible? Has the grades you've received ever stopped you from making your best effort?

Cheers,

Ron Neufeld
Canada's Best Boarding School

(Update : Some further reading here.)