Acta
Palaeontologica Polonica
36, 91-113 (1991). Jerzy Dzik Abstract.
Neither allopatric
speciations nor extinctions of lineages are directly observable in the fossil
record. This significantly reduces the value of inferred durations of taxa as
a basis for studies on patterns of evolution. The ranges of taxa detected in
rock strata are inevitably shorter than the real durations of lineages. Rates
of evolution estimated by counting reported ranges of taxa therefore appear
higher than they really were. Biometric studies of gradually evolving lineages
indicate that the durations of ‘species’ (morphologies) were
actually many times longer. Therefore, the ancestor-descendant relationships
along monospecific lineages remain the most important subjects of study in
evolutionary paleontology. A way, in which an ancestor-descendant hypothesis
can be falsified, is presented.
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