I’ve written a little about evolution in response to climate change, but it’s important to remember that life responds to our other ecological impacts as well. Thanks to habitat destruction, pesticide use, and various other forms of pollution, there has been a well-established decline in insect populations, all around the world, including pollinators. Most of the focus has been on how that will affect human food production, but it’s also a major concern for broader ecological collapse. Given how important insects are to ecosystems, not just as pollinators but also as predators, as prey, as scavengers, and as detritivores, their decline is a problem for the world. The thing about this sort of collapse is that, as with global warming, it’s a dynamic process. It’s not like a Jenga tower, where pieces are removed one at a time until the inevitable downfall – the “pieces” of an ecosystem respond to what’s happening around them.

What happens when there are fewer pollinators? Well those that can, make do without:

Scientists at the CNRS and the University of Montpellier1 have discovered that flowering plants growing in farmland are increasingly doing without insect pollinators. As reproduction becomes more difficult for them in an environment depleted in pollinating insects, the plants are evolving towards self-fertilisation. These findings are published in a paper in the journal New Phytologist dated December 20, 2023.

The first thing to note is that the flowering plant in question is a particular species of pansy, Viola arvensis, which is already known to have the ability to reproduce via self-pollination, or “selfing”. I think that’s important to state clearly, because the completely new development of this ability would, in my view, be a much more dramatic discovery.

In previous posts, there was some question as to whether changes observed were truly “evolution”, as opposed to something smaller. Selfing is already a known trait of V. arvensis, so how do we know this isn’t just the plants taking care of business with the traits at hand? Well, it clearly is that, of course, but in this case, the research team used a version of “resurrection ecology” to test whether the change was actually a genetic shift in the population. They took seeds that had been collected decades ago, between 1992 and 2001, and used them to make a genetic comparison. Not only is there movement towards more selfing, but also towards smaller, less attractive flowers, and less of a reward for pollinators(PDF):

• We used resurrection ecology methodology to contrast ancestors and contemporary des-
  cendants in four natural populations of the field pansy (Viola arvensis) in the Paris region
  (France), a depauperate pollinator environment. We combine population genetics analysis,
  phenotypic measurements and behavioural tests on a common garden experiment.
• Population genetics analysis reveals 27% increase in realized selfing rates in the field during
  this period. We documented trait evolution towards smaller and less conspicuous corollas,
  reduced nectar production and reduced attractiveness to bumblebees, with these trait shifts
  convergent across the four studied populations

This makes a great deal of sense. Big, showy flowers take energy to produce and maintain, and the same is true of nectar. If you’re not getting any benefit in exchange for that investment, then most of the flower becomes little more than a liability. Those selfing plants that have smaller flowers will have more resources to invest in seeds than their showier counterparts.

On the surface, this could be seen as a good thing. Yes, we’re messing up ecosystems, but the plants are adapting! They’re finding a way! The problem is that, as the authors mention, this is likely to be one part of a feedback loop. The decline in flower size, attractiveness, and reward will make it that much harder for those pollinators who are still alive to get the food they need, putting further pressure on them. This will exacerbate the pollinator decline, which in turn will maintain the pressure towards smaller flowers, and so on, with effects that resonate throughout the ecosystem.

There is, however, one thing I want to stress beyond the ever-present need for systemic change and further research, and that is the importance of research collections. This study was possible because someone, decades ago, collected seeds and stored them in the right conditions. When science is discussed in the general population, a lot of attention is paid to the results. New discoveries and dramatic news make the best headlines, but all of that stuff is supported by the unsung work of generations who came before. Often, that’s the data collected and the papers written – the official records of research that can be copied, shared, and used. There are also contributions from more “hobbyist” sources, like the journals of birders and botanists who write down when the flowers appear in the spring, or when the birds start migrating in the fall.

And then there’s the physical record. During my brief stint as a working ecologist, we gathered lots of data, including DNA samples, but I don’t think those were preserved. Earlier, when I worked at a natural history museum in college, my main job was to create museum specimens out of dead animals. It was mostly window-killed birds, with a few mammals picked up on the side of the road. I and my fellow student workers skinned them, preserved the skins, and added them to the museum’s research collection. These weren’t made for display, or for any particular research project, but rather to create a databank of sorts, that can be used in the future when new questions and new techniques arise.

The seeds used in the pansy study were part of a similar collection, and I think that’s an aspect of science that should get more attention than it does. It’s also a part of science that, like the hobbyist journals I mentioned earlier, can be done by those of us who are not trained scientists. Even in the midst of ecosystem collapse, it’s important for this archival work to continue, both to understand what’s happening, and to answer questions that – currently – we don’t know enough to ask.

Beyond the actual acquisition of specimens, these collections also require active maintenance. Organisms, as you may be aware, tend to fall apart when they die, and even things as hardy as seeds need to be kept in the right conditions.  That means paying people to do that work, and paying for the materials those people need. Without that investment, neglect is inevitable, and entire collections are put at risk, and these specimens, as biological snapshots from particular moments of time, cannot be replaced.

I can’t help but tie one pattern of neglect to another. Research collections are imperiled for the same reason our biosphere is in peril – the system in which we live does not value investment in our collective future. There is no arrangement whereby shareholders can reap ever-increasing profits from building and maintaining these collections, just as there’s no short-term profit in protecting the world for future generations, and so destruction and neglect seem to be the default. Obviously, I think we need to do systemic change about this, but at a smaller level, if you want to get involved, I suggest getting in touch with local universities and natural history museums. They’re likely to know what sort of help is needed where you are, even if it’s just donating a little to help keep things running.