Biology Reference
In-Depth Information
quantity of
each phenotype
A
genealogical and structural
proximity of phenotypes
pressure of selection by the environment
E1
E2
B
pressure of selection by the environment
E1
C
F
IGURE
4. The relativity of the order produced by natural selection.
Living
beings are subject to small variations in each generation. There is therefore a high
correlation between their genealogical and structural proximity.
A:
If they were
entirely and only subject to this variability, each form would be imperceptibly dif-
ferent from its closest relative. All living beings would form a continuum. No
species would be created.
B:
To create a species the action of selection is needed
to eliminate or promote certain variants rather than others.
C:
Different variants
are selected and different species formed depending on the characteristics of this
selection, which change from one environment to another.
events — but they are based on diametrically opposed theoretical
contexts.
There is enormous statistical variability in the physiological
phenomena which occur inside organisms. This has always been
interpreted as resulting from deterministic mechanisms with noise,
