Additional biases in quantifying diversity

Additional biases in quantifying diversity -...

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Additional biases in quantifying diversity: thickness of sediments different sediments deposit at different rates so that the resolution is quite different among sediments (affecting the rate (dt) component of the dN/dt calculations). Area of exposed sediments are not always representative of the temporal and spatial scales one might want to sample/represent in a fossil assemblage. Additional artifact of the age of the rocks known as " the pull of the recent" Young rocks are less likely to be destroyed by the forces of time than are old rocks. This means that last occurrences of a fossil are more likely to be better recorded than first appearances (actual first
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Unformatted text preview: "appearance" might have been exposed, eroded, reworked, etc. moving the observed first appearance up in time). Thus the duration of lineages will be "pulled" toward the recent (pulled implies an artifact of increased likelihood of a fossil to be recorded in younger rocks). Similarly, and extant group with a single fossil occurrence has a temporal range from its fossil date through to the present, but and extinct group with a single fossil occurrence has only that single date as a temporal range, even if it lived for a long time but was not deposited as a fossil. Biases aside, what does the record tell us? Does diversity increase with ti...
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