An Essay on Genetic-Adaptive Strategies and Mass Extinctions

Abstract

Research Article| August 01, 1970 An Essay on Genetic-Adaptive Strategies and Mass Extinctions PETER W BRETSKY; PETER W BRETSKY Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Search for other works by this author on: GSW Google Scholar DOUGLAS M LORENZ DOUGLAS M LORENZ Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Search for other works by this author on: GSW Google Scholar Author and Article Information PETER W BRETSKY Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 DOUGLAS M LORENZ Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Publisher: Geological Society of America Received: 13 Mar 1970 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1970, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1970) 81 (8): 2449–2456. https://doi.org/10.1130/0016-7606(1970)81[2449:AEOGSA]2.0.CO;2 Article history Received: 13 Mar 1970 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation PETER W BRETSKY, DOUGLAS M LORENZ; An Essay on Genetic-Adaptive Strategies and Mass Extinctions. GSA Bulletin 1970;; 81 (8): 2449–2456. doi: https://doi.org/10.1130/0016-7606(1970)81[2449:AEOGSA]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Recent studies of Paleozoic benthic marine invertebrate communities and ecological investigations of modern marine and terrestrial environments have provided information on patterns of faunal density and diversity, patterns which are commonly inferred to be controlled primarily by the physical milieu. Furthermore, there is some evidence indicating that genetic (chromosomal) variability in some invertebrates is correlated with the stability of the physical environment. Previously, these three areas of investigation had not been brought together in consideration of the evolutionary implications of long-term (tens or hundreds of millions of years) environmental stability. Three simple relationships are herein formulated from Recent and fossil data: (l) Environmental stability is positively correlated with diversity; (2) Environmental stability is negatively correlated with long-term biotic (taxonomic) stability; and (3) Therefore diversity is negatively correlated with biotic stability. To explain these observed correlations, we propose an evolutionary model based on genetic-adaptive strategies.We contend that the genetic-adaptive strategy employed by a species population depends in large part on the regularity, direction, and rate of change in environmental stability. A prolonged period of stability could significantly reduce a species' potential for survival in a more rigorous environment, and hence might be expected to precede a time of widespread or mass extinction. A homozygotic genome would be selected for (homoselection) by species subjected to long-term environmental stability, and it is this selection that could ultimately prove disastrous for survival in a later, only slightly less stable regime.Recognizing the teleological pitfalls that appear in any evolutionary model hinting at predictability, we nevertheless believe that attempts at the development of hypotheses based on adaptive patterns or strategies have a very definite heuristic value, if only in preventing the facile recourse to exotic environmental events as an explanation for major evolutionary events in the history of life. The proposed hypothesis of genetic-adaptive strategies should be viewed as a first approximation, perhaps, at best, leading to empirical research, which for now is introduced in an attempt to encourage investigation of environmental events leading up to periods of mass extinction. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.