Premium
The Chalk sea‐urchin Micraster : microevolution, adaptation and predation
Author(s) -
ROSE EDWARD P. F.,
CROSS NIGEL E.
Publication year - 1993
Publication title -
geology today
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.188
H-Index - 17
eISSN - 1365-2451
pISSN - 0266-6979
DOI - 10.1111/j.1365-2451.1993.tb00448.x
Subject(s) - predation , microevolution , invertebrate , adaptation (eye) , cretaceous , ecology , geology , biology , paleontology , population , demography , neuroscience , sociology
Serial variation between Micraster populations from successive zones in the Upper Cretaceous Chalk of Europe is widely cited as evidence for evolution at the species level, whether changes between species are interpreted as gradual or punctuational. That these changes were adaptive and represent an improved functional efficiency with time is also now widely agreed, if not whether the changes were independent of environmental change or a response to it. Dead specimens of Micraster were commonly encrusted by a wide variety of small invertebrates, presumably because they provided islands of hard substrate on an otherwise soft, muddy sea floor. Less commonly, there is evidence that living specimens of Micraster were susceptible to predation by gastropods and other organisms, one of the natural selection pressures favouring adaptation to a burrowing mode of life.