A fascinating study was published last week in Current Biology about the relationship between the hawkmoth and the Coyote Tobacco plant, Nicotiana attenuata. N. attenuata is wild flowering plant found in the west, related but not the same as the cigarette tobacco plant grown in the south. (You may recognize it as a relative of the Nictiana plant that is a favorite perennial in New England gardens). The plant has developed - as many flowering plants have - a symbiotic relationship with its pollinator, the Hawkmoth. The moth picks up and disperses the plants pollen. The the benefit to the moth is that it frequently lays its eggs on the plant's leaves. When the eggs hatch, its larvae (the caterpillars) have their first meal - the plant itself.

This is obviously not a mutually beneficial relationship. Too many caterpillars and the tobacco plant population would begin to drop, and possibly disappear. The plant faces a choice: adapt or die.

Scientists has recently observed a startling adaptation taking place. The plant normally flowers in the evening hours during Hawkmoth high flight times. Recently, however, the tobacco plant has begun to flower during the morning, attracting a new and different pollinator: a hummingbird that has no interest in devouring its provider of nectar.

This is evolution at work. The plant has a choice in a figurative sense. It doesn't have a working brain capable of strategizing a plan for its own survival. There is something more primitive at work. Something elegant in its simplicity, and powerful in its determination: natural selection.

Natural selection, one of Darwin's main ideas in his theory of evolution is commonly thought of as "survival of the fittest". It refers to the fact that there is a great deal of variation within a population or organisms, in this case the tobacco plants. Most of the plants flowered at night and had a higher likelihood of being eaten by Hawkmoth larvae. A few plants, flowered earlier in the day. The earlier flowering plants survived, thrived, and passed their genetic code on to the subsequent generation of plants. They're the ones who had higher survival rates. The balance shifted between night flowering plants and morning flowering plants shifted towards to morning plants.

Interestingly though, the night flowering plants remain. Scientists hypothesize that the moths, which fly over a much larger territory, are superior pollinator and capable of spreading the plant's pollen to plants further away than the hummingbirds are able to.

Regardless - more and more of the tobacco plants began to flower in the early morning hours. This adaptation gave the population of tobacco plants the opportunity to recover and stablilize, ultimately strengthening this new trait that aids their survival. The species has changed. It has adapted to thwart a negative force in its environment.
In your opinion does this show proof of evolution?