Black and White

I studied biological sciences in some form for eight years. Certain topics or examples seemed to come around again and again, pretty much every year: the organelles within a cell; meiosis and mitosis; food chains (and DDT); the chemistry of phoyosynthesis and respiration; the structure of a flower; the base pairs in a DNA molecule... and so on. There was a certain amount of resigned slumping of shoulders among my peers when these appeared on the blackboard or the Roneo handout (yes, I'm that old). At university level, lecturers were canny enough to adopt an apologetic tone and infer that they were sure we knew all this, but were going to tell us anyway. I suppose they were 'levelling up'

One regular spot on this merry-go-round was occupied by the Peppered Moth. In rural areas this exists in two forms: a grey-white moth with black spots (pepper) and a tiny proportion of the population that is almost entirely black (the 'melanic' form). The speckled variety is well camouflaged when resting on lichen-covered tree bark. The melanic form is much more visible and easily picked of by predators, which keeps it a small minority

At the hight of the Victorian, coal-fired industrial boom, cities became choked with smoke and smog. Buildings, gardens and trees were coated with black grime. Suddenly, a grey-white moth became a sitting duck, and a black one was no longer the ugly duckling. According to Butterfly Conservation, "the first black Peppered Moth was recorded in Manchester in 1848 and by 1895, 98% of Peppered Moths in the city were black". When we cleaned up our air quality in the 20th century, the population reverted to its previous proportions. Of course, we were told this parable to illustrate the power of natural selection, the mechanisms by which it led to the origin of species, and the genius of Charles Darwin

I got quite excited when I saw this moth, not at all well camouflaged on our cream limewashed wall. Sadly, after a bit of internetting, I'm pretty sure it's not a peppered moth; I think it is a moth in the same Family called a Willow Beauty. A charming name but I'm not sure how it came by it, as its caterpillar feed species range from hawthorn, privet, honeysuckle and clematis to hardcore stuff like ivy, yew, pine and cypress, but seldom willow. I was intrigued by the ragged trailing edge of the wings - I guess there are probably aerodynamic reasons for that

Update on the bee mysteries I described yesterday: We found a queen in the colony, looking in pretty good shape. We marked her with a green spot, to make it easier next time. The colony is, if anything, even more active, and resisting attention from wasps. Even better, we saw them bringing in pollen, suggesting they are expecting some brood to feed. Steady as she goes. Let's hope the coming week of good weather gets them up and running