Organisation at Population Level 43
r: A great number of offspring. Short life span, many reproductive
generations; increase of fertility span in relation to life span; easy
propagation of seeds; opportunistic behaviour. Characteristic representatives: many insects, small mammals, weeds, many small seeds
(e.g. fig tree) or eggs, etc.
K: Fat or nutrient reserves, hibernation, durable seeds, long life span,
nursing, nuptial parades (reproduction of albatross or other birds),
grooming of offspring; complex defence systems against enemy
attacks; learning by experience; social behaviour. Characteristic representatives: big serpents, birds, mammals, species with shells or fur,
big long-lived trees, acorns etc.
The speed of evolution is connected with the survival strategies:
r: Rapid evolution, favours the creation of new species
K: Slow or nonexistent evolution (perfected species, e.g. big trees, shark,
albatross, bear)
The first settlers in a new environment (ecological void) are favoured if they
have an r strategy and are opportunistic populations with a great migrating
ability. They take advantage of the absence of hard competition and take
possession of the ecological niche very quickly. They can deal more easily
with the changing or unstable environment and unexpected phenomena .
If needed, they migrate elsewhere. Towards the end of ecological succession, the permanent, mature inhabitants will settle in the environment. They
take advantage of the prevailing stability and the predictability of changes
and they have learned to be effective in the exploitation of resources. They
can deal with intense competition and they gradually prevail . They cannot
recover easily if the population is greatly reduced, and that’s why they need
more protective care.
In nature, r and K strategies constitute the extreme cases of a continuous
range of intermediate strategies. Prevalence of the first or the second in a
greater degree contributes to the correspondingly lesser or greater stability
of the ecosystems.
In human populations, r and K strategy elements occur such as polygamy—the subordination of women and their utilization in the maternal
role—on one hand, and the long-term raising of children, the emancipation
of women, and the development of civilizations on the other.
3.7 thE huMan PoPulation
The population of the human species constitutes a special case in the
biosphere’s history. Man significantly modifies the natural environment;
r: A great number of offspring. Short life span, many reproductive
generations; increase of fertility span in relation to life span; easy
propagation of seeds; opportunistic behaviour. Characteristic representatives: many insects, small mammals, weeds, many small seeds
(e.g. fig tree) or eggs, etc.
K: Fat or nutrient reserves, hibernation, durable seeds, long life span,
nursing, nuptial parades (reproduction of albatross or other birds),
grooming of offspring; complex defence systems against enemy
attacks; learning by experience; social behaviour. Characteristic representatives: big serpents, birds, mammals, species with shells or fur,
big long-lived trees, acorns etc.
The speed of evolution is connected with the survival strategies:
r: Rapid evolution, favours the creation of new species
K: Slow or nonexistent evolution (perfected species, e.g. big trees, shark,
albatross, bear)
The first settlers in a new environment (ecological void) are favoured if they
have an r strategy and are opportunistic populations with a great migrating
ability. They take advantage of the absence of hard competition and take
possession of the ecological niche very quickly. They can deal more easily
with the changing or unstable environment and unexpected phenomena .
If needed, they migrate elsewhere. Towards the end of ecological succession, the permanent, mature inhabitants will settle in the environment. They
take advantage of the prevailing stability and the predictability of changes
and they have learned to be effective in the exploitation of resources. They
can deal with intense competition and they gradually prevail . They cannot
recover easily if the population is greatly reduced, and that’s why they need
more protective care.
In nature, r and K strategies constitute the extreme cases of a continuous
range of intermediate strategies. Prevalence of the first or the second in a
greater degree contributes to the correspondingly lesser or greater stability
of the ecosystems.
In human populations, r and K strategy elements occur such as polygamy—the subordination of women and their utilization in the maternal
role—on one hand, and the long-term raising of children, the emancipation
of women, and the development of civilizations on the other.
3.7 thE huMan PoPulation
The population of the human species constitutes a special case in the
biosphere’s history. Man significantly modifies the natural environment;