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Hypothesis 8

The biological causes

Parade, Cusco, Peru, 27. 8. 1989
Parade, Cusco, Peru, 27. 8. 1989


The first task is to describe the biological mechanisms that led to the development of the human brain. The biological causes for the development of the human brain, brain growth and the end of thereof must be explained before the beginning of the cultural achievements of Homo sapiens are explored.

The second task is to describe how the existing human brain, through a functional change, could become the biological basis of the mind.

Explanation:

If I can’t make out the details of an object well enough, I would make use of a magnifying glass. If I still want to be able to see finer details or material structures, then I’ll use a microscope. If I want to research a subject scientifically, one possible method is to divide the subject into many small problem areas, each of which can then be examined individually. In the end, the results are combined once again.

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Mayr then describes how a function shift works as follows:

Parade, Cusco, Peru, 27. 8. 1989
Parade, Cusco, Peru, 27. 8. 1989

During this kind of functional shift, a structure always goes through a phase in which it can simultaneously perform two functions, such as Daphnia’s antennas, which are both a sensory organ and a floating rudder. This functional duality is possible because the genotype is a highly complex system that always produces certain aspects of the phenotype that are not directly promoted by selection but are simply “by-products” of the genotype favoured by selection.

Such by-products are then available for the acquisition of new functions. They are the ones that allow the front limbs (with a flying membrane) of a tetrapod to act as wings, or the lungs of a fish, as a swim bladder. In the phenotype of every organism there are numerous “neutral aspects” that are “admitted” by natural selection i.e. not eliminated but which have also not been specifically favoured by it.

These kinds of components of the phenotype are available for the transfer of new functions. Functional shifts are also known in macromolecules and behavioural patterns, for example, when plumage cleaning becomes part of advertising behaviour in certain ducks.
(Mayr 2002, p. 491)

Mayr continues on the intensification of the function of an existing organ:

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Hypothesis 4

Evolutionary innovations

Parade, Cusco, Peru, 27. 8. 1989
Parade, Cusco, Peru, 27. 8. 1989


According to Darwin and Mayr, evolutionary innovations arise from the functional displacement of existing organs that can simultaneously perform two functions but not by selectively favouring a new organ that is not yet functional.

Explanation:

According to Charles Darwin’s theory, evolutionary changes take place through very small steps.

According to the model of gradualism in geology, in which mountains that are several kilometres high unfold a millimetre at a time and the Atlantic Ocean, hundreds of kilometres wide today, only opens up a few centimetres each year as a result of shifting plates, the evolution of living beings conceivably takes place in small steps from one generation to the next.

When changing size, colour and other characteristics that permit a smooth transition, the idea of gradual change does not present any difficulties. But how does it look when the fish suddenly becomes a land animal? When the legs suddenly begin to move and the lungs suddenly begin to breathe, and the skin does not dry out?

When a small predatory dinosaur becomes a bird – where does it suddenly have feathered wings to rise into the air?

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