Spillover

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As the water in my paintbrush froze into slush, I sketched some shadows spilling over the old rail trail in the last moments before sunset. This stretch of trail fared better than other sections that were washed out by last week's unprecedented coastal flooding.

(The russet-colored blob is one of my favorite features of the trail. In about four months it will be a green mound of blooming lilacs.)

Islands of domestication

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I drew this to illustrate another Forum paper for the scientific journal Oikos. Here is a summary of the study, “Insularity and early domestication: anthropogenic ecosystems as habitat islands” (by Robert N. Spengler III):

Maybe humans take too much credit for domesticating plants and animals. This Forum paper argues that the human-friendly qualities of our pets, livestock, and crops could have arisen without selective breeding or other human-centric mechanisms that are usually assumed. Instead, it explores an ecological mechanism: the island syndrome.

Think of early farms and villages as islands. The author draws parallels between the processes of domestication and island evolution, suggesting that the same ecological forces may be responsible for both. Both island plants and cultivated crops tend to have bigger and less dispersible seeds than their ancestors. Animals on islands and in human habitats can lose flight ability, fear responses, and patches of pigmentation, among other changes.

Why such parallel patterns of evolution? It could be that when plants and animals find their way to islands or other insular habitats—ranging from early villages to modern cities—they are released from predation and competition pressures. Domestication scholars and island biogeographers would benefit from comparing notes, the author concludes.