What is going on with invasive knapweed? OR How I spent my PhD

Over the course of my PhD work (published here, and most recently here), I have found evidence for evolved differences in phenotype (in other words, in their morphology, development, phenology, stress responses) between native and invasive populations of diffuse knapweed. Why is that interesting? Well the invasive populations didn’t even exist until barely 100 years ago. And something about them has let them succeed and spread over vast areas of their new habitat. Perhaps what has made them so successful can be revealed by comparing the invasive diffuse knapweed populations to their closest relatives, the native diffuse knapweed populations.

Knapweed in the greenhouse, 2009.

Why invasives are problematic

Common question: Why should we worry about species moving around, anyway, haven’t they always done that? A forest is a just a forest and a grassland is just a grassland after all. What are you getting so worked up about? Aren’t humans the worst invasives?

Answer: Yeah, humans are the worst invasives, but I can’t really justify mass extirpations for humans. Not yet, anyway. Though limiting birth rates probably isn’t a terrible idea.

Check out my guest post at NiB

Here. I went a little citation happy, but the folks at Nothing in Biology Makes Sense didn’t seem to mind.

Why Study Invasions

In some circles, “applied” science is a bit of a dirty word. But fear not, basic scientists! There are plenty of reasons one might wish to study invasive species as a means to approach pure and beautiful knowledge alone.

I will happily kill you. Diffuse knapweed in the Okanagan, British Columbia.

Two sides, same coin

Plants and people change, evolve, together.  We take advantage of them. We use them for their sweetness, their fibers, and their ability to fill our bellies. The tractability of domesticated plants has allowed mankind to cover the globe and to live in habitats to which we are not adapted. Wherever we go, if we can plant a few staple crops, we can survive, even thrive. Plants have put clothes on our backs and roofs over our heads. They may yet solve our energy crisis, even our CO2 producing habit. We have a sweet deal going on here.

And they take advantage of us.  In mankind, many plants have found the best of nursemaids. We spread them far and wide, until a single species such as corn covers million and millions of hectares. With the help of man, no ocean is too vast to cross, no habitat exists that can’t be made more suitable. For our chosen favorites, nothing is too much to ask. If we colonize new planets, we will take them there too.  Some plants take advantage of us without anything in exchange. We don’t even notice as we spread them around or accidentally make habitats more to their liking. They have a sweet deal going on here.

This co-dependence between mankind and many plant species permeates life, modern and ancient. The gradations between ‘us using them’ and ‘them using us’ is what this blog is about. Welcome to my ramblings on ethnobotany, domestication, invasive species, and evolutionary ecology.