|Ready for stickleback - but will it work?
- How many attempted experiments failed for logistical reasons and just never get reported?
- What are the various reasons why we fail?
- What do we learn from our various experimental failures?
- When is failure a productive source of insight, versus a plain old flop?
|Viserys and his golden crown.
|The Wise Masters are about to meet Drogon the dragon
|Ned Stark pays the price for honor - or is it naivete?
|Ormond and Dugout Lakes on Vancouver Island. The narrow marsh separating them can be clearly seen. The barrier to dispersal was built across that marsh.
Presumably because the two lake basins are connected by a narrow marsh (~20 meters wide) that permits free movement of migrants between the basins (Bolnick et al 2008 Biol J. Linn Soc.). So, obvious experiment: create a barrier to movement, and track the subsequent emergence of genetic and phenotypic differences, then remove the barrier and watch those differences collapse. All I needed was a barrier. So, in 2007 I found myself back in British Columbia with two field assistants and an extra week on our hands between other tasks. I had planned ahead and obtained permission to build a barrier and leave it in for a decade (~10 generations). All that remained was to make the barrier reality. We installed sturdy steel 8 foot tall fence posts in a transect across the entire neck of marsh connecting the two lakes. We attached chain-link fencing, carefully sunk into the substrate of the marsh all the way across (~30 meters wide including semi-marshy habitat that probably rarely allows migration, but we had to block that just in case). We then attached a fine screen to this fencing - We had to build it with fine enough mesh to prevent passage even of juvenile fish, so we used a sturdy type of coarse mosquito netting. One layer of netting on either side of the fence. Then we installed another layer of chain link fencing to sandwich a mosquito net in between, for added strength. All of this was buried deeply into the substrate, which involved several days of lying face down in muck in our wetsuits cutting into the peat with a saw. The end product looked satisfyingly sturdy (Fig. 2).
|Building the barrier across the marsh.
Now, I knew all along that water flowed from the smaller basin into the larger one – imperceptibly slowly, but still flowing. And I knew therefore that the fence would get water pressure and sediment build-up. But I figured water would keep seeping through, maybe raise the water level a bit. I knew this might be wrong, and the whole thing might fall apart due to water pressure. But, it was a risk I was willing to take.
|The Experimental outcome – no experiment
So, I took a risk, and my design did not work, so the experiment flopped, literally on its side. On the plus side, the total cost was maybe $1000 in materials and three people’s time for 5 days to build it. Low cost, high possible reward, high risk. Did I make the right decision to try this? Perhaps not, but it was exciting while it lasted and makes a fun story.