I accept that that all living organisms on Earth today are products of biological evolution. They are all descended from earlier forms of life.
I appreciate that biological evolution is the consequence of random mutations in the genetic material of organisms, and the selection, through natural, sexual or artificial selection, of mutants that are of biological advantage.
However, there are some characteristics among animals that I find difficult to explain in terms of these three kinds of selection. I am among those who wonder whether there is not some other selective process at work. I have no idea what it is.
Here I will give just four examples to illustrate my thinking.
The peacock’s tail feathers
Darwin appreciated that the colour pattern on the tail of the peacock was difficult to explain in terms of natural selection, and he postulated it was the result of sexual selection (Figures 1 and 2). Peahens prefer males with colourful patterns on their tail feathers. This view is now widely accepted.
We are, of course, still left with the question: Why should the females be genetically programmed to prefer more colourful tail feathers? Several hypotheses have been put forward, none of which I find convincing.
Let us consider just the striking eyespots (Figure 1). When we look closely at one of these, we see that it is amazingly complex, made up several hundred filaments or barbs. Each barb has several colours, and it is different from all the other barbs; but together they produce the very beautiful multicoloured eye spot. I wonder how many genes are involved in creating this pattern.
Is the peahen really sensitive to this degree of detail?
The sand patterns of the male Puffer fish
The white-spotted pufferfish (Torquigener albomaculosus) is a small fish found off the coast of Amamai Oshimam Island south of Japan. The male creates a large, geometric circle in the sand to attract females (Figure 3). If a female decides to mate, she will descend to the floor of the circle The male will approach her, and they will press their bodies together and vibrate. The female then releases her eggs, which are then fertilised by the male. The female then disappears. The male remains there for about six days, possibly to guard the eggs.
How does this amazing behaviour of the male Puffer Fish come about through evolution? No doubt it will be argued, as in the case of the peacock feather, that it is the outcome of sexual selection. The female chooses the male that constructs the most perfect circle of indentations in the sand. I will not be convinced.
It is difficult to envisage the selective advantage of the early stages of the evolution of this extraordinary behaviour.
Leaf Insects (Phyllidae)
These insects look extraordinarily ike green leaves (Figure 4). Presumably, the more their evolutionary ancestors looked like a leaf, and less like an insect, the less likely they would be eaten by an insect-eating predator.
But is this degree of detail necessary for the predator to be deceived?
Concert pianists
I am amazed at the concert pianist’s capacity to learn and memorise the sequence of tens of thousands of notes, and combinations of notes, in a whole series of piano concertos and other pieces of music; and then to play these notes by making extremely complicated and rapid movements of their fingers on the piano keyboard.
See, for example, the numerous videos of Yuja Wang playing piano concertos and other compositions without a score (Figure 5).
What kind of selection pressures in the evolutionary environment were responsible for this amazing aptitude?
Figures
1. Peacock 1
2, Peacock 2
3. Puffer fish
4. Leaf insect
5. Concert pianist
Figure1
Figure 2
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Figure
Figure 4.
Figure 5
BIORENAISSANCE 