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Biology Articles » Evolutionary Biology » An Effort to Explain the Process of Body Formation » Chapter 2

Chapter 2
- An Effort to Explain the Process of Body Formation

The book of Robert Ardrey, ‘Territorial imperative, a personal inquiry into the animals origins of property and nations’[4], is treating the concept ‘territory’ extensively by different aspects and through many examples, most predominantly among mammals and birds.

He describes among others territories of the perspective “society of outward antagonism, isolated and unified by the defense of a social territory” [7], and one example is the unicellular beings, which are called slime moulds [5].

The slime mould species he is describing was discovered in 1935 and researchers have since then been cogitating over theirs behaviour. Their history is presumed to go back as far as to the first billion years after the origin of life.

These fungi are of equal size with leucocytes and they exhibit a similar shape. They feed themselves through bacteria in humid soil. Every third or fourth hour they divide and the population is therefore increasing rapidly.

When the population has consumed the nourishment within its territory, the cells are entering into the second phase of their life cycle. They begin to form societies. Around a founding cell the others are clustering in a growing lump and cling on to the others, until they have formed a wrinkly “slug”, which is visible to the eye. Now this society of individuals is beginning to behave as one organism and it is even moving in the direction towards heat or light. Finally, one part of the society is differentiating and begins to form a peduncle, which they make stiff, using a secretion. Thereafter the others are crawling up to the top of the peduncle, where they are forming a sphere of spores, the seed of a new generation.

That is the way of living that has been modelled about one billion years ago and that still is working.

One aspect of the social behaviour of the slime moulds (Myxomycetes) has been able to explore on a laboratory level. That is what Ardray defines as a society with an external hostility, which is founded on the basis of a defense of a territory of a society.

One scientist has, according to Ardray, demonstrated that the size of the society territory at a certain species of slime moulds is constanr and he has proven that has been suspected for some time: that the means by which a society is being defended is a gas, which is repelling other groups to a certain distance, while simultaneously attracting the members of the clan. An American scientist has made an extraordinarily interesting observation, which is showing that the cells are able to communicating. When they were put into a Petri dish, they were distributed as evenly in their first phase of life, as if they were repelling each others. (We would prefer to name it individual distance). When the time for gathering had come, it appeared to be, as if a signal had been given, obeyed by everyone.

Further one observation: the amount of fruit-bearing societies within a certain area is independent of the amount of individuals. In other words: if one had a thousand cells within an area, they could form ten groups, but if one had ten thousand, they would still form ten groups. The societies were in some way a function of the space, not of the amount of individuals.


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