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Evolution

Brian MacCormaic writes:

"Hello Derek and team. I've just returned from volunteering in South Africa as a development worker. I was in Limpopo province, which is in the north of the country about 300km from the Zimbabwe border.

While there, I took many 'standard' wildlife photos, particularly in Kruger National Park, which I visited as often as I could. But while these were amazing and exciting to watch, more spectacular and interesting to me were the insects and bugs around our house, which was out in the country. They seemed to come out in their biggest numbers and varieties in the evenings around Feb to May and Sept to Nov, when it wasn't too cold or hot. Locusts or grasshoppers of every shape and shade wandered across our garden; huge centipedes (Chungalola) trundled along like express trains, busy going nowhere in particular; stick insents and praying mantis; enormous beetles that seemed to aim themselves at nothing in particular, and would then rattle across the sky and clatter into the gutter or window.

Toads and frogs would keep us awake at night when rain was due, and yet, although you could hear them in the early morning, they were virtually invisible, so good was their camouflage. But the most spectacular of all to me were the moths and butterflies. They came in such a wide variety, each seemed more brilliantly coloured and marked than the next.

But what I would like somebody to explain to me (in plain layman's language) is: how did they evolve the particular markings they carry. I can understand why, and how effective they are for camouflage or for scaring off potential predators, - but how and why did the process of evolution begin to form these markings in the first place? It seems to me that the 'eye' on a moth's wing would only be effective when it has been fully formed. The beginning of an evolutionary process to form that 'eye' however, would surely have no genetic advantage over other moths unless it became a complete 'eye' instantly - in one generation.

I've attached an example of one of the moths(?) I encountered (moth 1,2, and 3). But I couldn't find a name for it. It's a bit like an Emperor Moth I've seen, the caterpillar of which is, I believe, a local delicacy for Africans, known as the Mopane Worm. I've seen - but never tasted them!

I was intrigued at the detail in the 'eye' on the wing, but it was only when I enlarged the photo that I saw the 'bat's head' detail on the back of the moth - with eyes, mouth, nose and horns.

I've attached one or two other craturs I encountered in my garden there, which might be of interest.

Regards, and hope you or your listeners can enlighten me.

Brian MacCormaic"


Moth 1


Moth 2


Moth 3


Insect 1


Insect 2


Insect 3

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