Evolution of biological complexity and its relation to taxonomic longevity in the Ammonoidea
Article Abstract:
Ammonoids are extinct mollusks that displayed high rates of evolution during their 330 year-old fossil record. Studies of changes in the intersection of the Ammonoid septum and its shell exterior (sutures) were made to ascertain whether or not evolutionary complexity significantly reduces susceptibility to extinction. While the sutures exhibited increasing complexity over time, no survival differentials exist between simple and complex members of the genera, implying that taxonomic longevity is uncorrelated with evolutionary complexity.
Publication Name: Geology
Subject: Earth sciences
ISSN: 0091-7613
Year: 1992
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Temporal variation in calcification in marine cyanobacteria
Article Abstract:
An analysis describing cyanobacterial calcification episodes (CCEs) is presented. The CCEs refer to the proliferation of calcified cyanobacteria in marine environments. These episodes were intense during the Cambrian-Early Ordovician, late Devonian and Mid-Late Triassic. Mild episodes occurred in the Early Carboniferous and Jurassic-Early Cretaceous while conditions exhibit the possibility of cyanobacterial temporal variation in the Silurian and Permian stages.
Publication Name: Journal of the Geological Society
Subject: Earth sciences
ISSN: 0016-7649
Year: 1992
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Genetic variation and reproductive isolation among phenotypically divergent amphipod populations
Article Abstract:
The freshwater amphipod Hyalella azteca appears to form at least two distinct species in southeast Michigan. A small-bodied ecotype occurs in habitats with predatory centrarchid fish, while a large-bodied ecotype is found in habitats without the predators. Gene flow between the ecotypes appears to be limited, with a high degree of reproductive isolation implied. No consistent genetic difference exists between the ecotypes, however.
Publication Name: Limnology and Oceanography
Subject: Earth sciences
ISSN: 0024-3590
Year: 1998
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- Abstracts: Erosional control on the geometry and kinematics of thrust belt development in the central Andes. Pretectonic and posttectonic emplacements of the granitoids in the south central Okchon belt, South Korea: implications for the timing of strike-slip shearing and thrusting
- Abstracts: The biological significance of fluctuating asymmetry and sexual selection: a reply to Palmer. Detecting publication bias in meta-analyses: a case study of fluctuating asymmetry and sexual selection
- Abstracts: Discussion on modern and ancient continental hypsometries. Discussion on continental eclogites and the Wilson Cycle
- Abstracts: Darwinian fitness and reproductive power: reply to Kozlowski. "Terminal investment" and a sexual conflict in the collared flycatcher (Ficedula albicollis)