Back in May, I said that there was nothing extaordinary about the maximum rate of branching that occurred early in the evolution of perching birds and that I would show my calculations in my next post. I want to go to the trouble of backing up my statistics on this so that I can use the… (read more)
It began with a mislabelled graph. My comment on that simple mistake led to my name being linked with those of the leading ecologists of my day and the designation of an entirely new pattern of seed dispersal and survival. I was a graduate student at the University of Western Ontario in 1984 and I… (read more)
Today marks the first anniversary for this blog. I would like to thank Miles Corak, who encouraged me to start. Miles has an influential blog on economics. My son Anthony arranged for the domain name and got me started in WordPress. I would also like to thank you, my readers. The Answer I have been… (read more)
The lopsided tendency of evolution to produce many species in one group while preserving just a few in other groups applies quite well to birds. I called this tendency Haldane’s Rule. Is there something special about groups, like the perching (or Passerine) birds, that dominate our biodiversity? Or is their diversity a natural outcome from a… (read more)
Canadians are obsessed with health care. Our publicly-funded system is one of a very few cultural differences (along with the length of our football fields) between ourselves and our great neighbours to the south. As such, medicare is a source of pride and identity. Jeffrey Simpson has recently pointed out that this pride is… (read more)
Those born between 1910 and 1930 saw fit to raise a generation which could care for them in their old age. Their children, the “Baby Boomers”, were not so far-sighted. Though the Earth has benefitted from the decrease in population growth in Western countries in the last 50 years and though we boomers have had less burdensome… (read more)
Ecosystems are messy places. The number of possible relationships between species grows exponentially with every species that enters the system. A fairly typical foodweb (see image below) of 70 species has 4900 possible predator-prey interactions. Despite that, food webs are suprisingly predictable. For one thing, most foodwebs have only 10-30% of the possible feeding relationships. This… (read more)
The fourth of five fundamental theories in ecology that I outlined in my last post states that landscapes – and the services they offer us -will wear out if too much natural habitat is removed. The actual percentage of the landscape that qualifies as “too much” is up for debate. The original “percolation theory” simulations… (read more)
