July 22

In marshaling evidence in support of natural selection, Darwin writes of the prolific degree to which organisms of all kinds produce offspring. The argument claims that the world would soon be overrun should all the progeny and subsequent generations survive from a single parentage. Thus nature is daily scrutinizing and on balance selecting only those progeny, all things being equal, who have some advantage be it small or great.

Take the wild columbine as an example. The dried seed pods are brown now and pointed upright so that if you grasp the sere stalk and gently shake it, the sound of a rattle is made. I placed my hand underneath a single pod and bent it with the other so that the seeds fell into my palm in a neat pile. I counted nine coal-black seeds the size of small peppercorns. A little arithmetic assists the example. There were 18 total pods (in clusters of 3 or 4) from the entire plant. 18 times 9 equals 162 total seeds from this single columbine. If all the seeds were to successfully overwinter and germinate next spring, the knot garden would be overrun. Let’s assume that last year’s columbine also similarly produced 160 or so seeds. One evidently survived, making the likelihood of survival a meager 1 in 162.

Dandelions must assuredly be less, with their silken blowies everywhere in late May. I wonder about the maple keys or acorns, particularly in those mast years when production seems to be in the thousands.

It is a wonder we have columbines or dandelions or oaks at all.

Notes:

Bouncing Bet (Soapwort) on South Road in bloom.