Transgenics in the news: salmon and pigs

23 Aug

This conversation on PRI’s On Point discusses many issues surrounding transgenic salmon, including biological, conservation, and ethical ones. It presents two good case studies for transgenics.

Biochemistry of digesting transgenes & transgene products

Gene flow, fitness effects of transgene on wild populations

Gene flow, conservation issues and suggested solutions

Transgenics: AquaBounty Salmon and the Enviropig


“Rust never sleeps.”

26 Jul

Escalating Threat of Wheat Rusts

Science Mag editorial

“Last month [6/10], nearly 600 scientists from more than 80 countries convened…  to discuss the world’s most widely planted crop… [and] the rapidly spreading fungal diseases known as wheat rusts…  causing epidemics that require urgent action.

In the 1940s… new plant varieties [were bred] to resist the causative pathogens… But in 1999, a virulent fungal strain (Ug99) was detected… new virulent and aggressive strains of yellow rust fungus (also known as stripe rust) now pose a severe threat to the world’s wheat supply… This epidemic trend may continue because the aggressive strains, which can tolerate higher temperatures, are still evolving [emphasis mine].”

Activity: Present this as a problem, and have students come up with solutions.

Activity: Analyze each others’ solutions for evolutionary explanations. For example, why are fungicides a short-term solution? What are the implications of some solutions for genetic diversity? For example, of replacing wheat with certain varieties. How can humans speed up evolution? Identify the postulate of natural selection we modify to speed up evolution, and explain why other species in nature can’t do this.

Preparation: What guidance and foundational knowledge do they need for this?

Yangtze finless porpoise

26 Jul

Science Mag news article:

Case studies from plant breeding?

26 Jul

Hybrid The History and Science of Plant Breeding by Noel Kingsbury University of Chicago Press, Chicago, 2009.

Reviewed in Science:

Debates: a source of student motivation

26 Jul

Jonatham Schramm, an ecology PhD doing an education post-doc, floored me with his quiet ability to get students discussing GMOs, mass transit, and consequently, biology, with passion.

I also notice students pipe up to correct peers or instructors like at no other time. I’ve seen 40 minute debates cause astonishing 40 minute gaps in Facebook news feeds.

So, debates! A great activity, because it generates motivation and requires self-directed learning at many levels.

Here’s an example question: Should 40 smuggled tomato frogs be returned to Madagascar?

New category!

Student-directed curriculum

26 Jul

Tropical Rain Forest Ecology, Diversity, and Conservation
Jaboury Ghazoul and Douglas Sheil
Oxford University Press, Oxford, 2010

A bit from this book’s description crystalized an idea I’ve been mulling over. How do you plan for the information students will want to know to solve a problem? I could see this becoming a disaster, where they get frustrated that they “don’t know/aren’t being told the answer”,  which really is them frustrated because don’t have enough foundational knowledge to start brainstorming. I think this is where the expert serves as guide, helping students to pursue their ideas in useful ways by naming related themes or asking leading questions. The exploration mirrors the field of inquiry, and so may mirror its many directions.

Wouldn’t it be cool to devote a short early portion of the course–a day, week, more–toward a case or problem, finding and mapping out all those directions students are interested. Then these become the curriculum for the course. For example, here’s the bit I mentioned earlier:

“The book starts by introducing the variety of rain forest plants, fungi, microorganisms, and animals, emphasising the spectacular diversity that is the motivation for their conservation. The central chapters describe the origins of rain forest communities, the variety of rain forest formations, and their ecology and dynamics. The challenge of explaining the species richness of rain forest communities lies at the heart of ecological theory, and forms a common theme throughout.”

Take a super cool challenge like tropical diversity. It is new to many students, holds tons of fascinating case studies, and is a subject of contemporary debate for ecologists and evolutionary biologists–maybe others, I don’t know. And, it is a particularly tantalizing problem because there are tons of accessible ideas that seem like they should explain it, but don’t. Exploring these ideas in turn could be the curriculum of topics, with students choosing which to include with guidance from the teacher. What this does is start with an integrated curriculum, which usually only the teacher ever grasps, so that the higher level knowledge skills are constantly applied and call for (motivate) the development of the other levels. Students struggle with conclusions in lab reports, and in drawing valid connections to bigger pictures. Here, the connection to big picture establishes the validity of each topic at the outset. Also, this mirrors the scientific method, both Popperian and Lakostian.  I would love a to be a student in a course like this!

One note is to not simply split up topics for group projects. That would cause everyone’s learning to be contingent on the quality of one group’s learning, which personal experience suggests demotivates everyone. An alternative is to use group projects on every topic, each on a subtopic, where this augments other activities designed to develop foundational knowledge, etc.

Evolution of plants on land, etc.

26 Jul

Problem: Given the environment and the extant diversity at some point in the evolutionary history of plants, what traits might increase fitness?

Analysis would include

assessing the unexploited resources and challenges in the environment

identifying or imagining plant traits or processes that can use resources or escape challenges in a way that increases reproductive success.

Students have shown great creativity in imagining new or new combos of traits. This was after an introduction to two ecosystems, and that foundational knowledge was both a good scaffold and an evident source of bias in their ideas. One idea is to use this scaffolding bias as a tool to limit the problem solving to a class of traits like those affecting life history. The life histories of plants is a new idea for many (most?) students, and specifically, the life history evolution that accompanied the evolution of plants can be a unique, fascinating discovery. It inspired this student to study evolution!