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Full-Text Articles in Earth Sciences
Symbiogenesis. A New Principle Of Evolution Rediscovery Of Boris Mikhaylovich Kozo-Polyansky (1890–1957), Lynn Margulis
Symbiogenesis. A New Principle Of Evolution Rediscovery Of Boris Mikhaylovich Kozo-Polyansky (1890–1957), Lynn Margulis
Lynn Margulis (1938 - 2011)
The following is a heavily edited transcript of my illustrated lecture, that included our 14 minute video (with a 2 minute animation model) that shows each step in live organisms hypothesized in the origin of nucleated cells from bacteria (“eukaryosis”). New observations presented with modern examples of live phenomena make us virtually certain that B.M. Kozo-Polyansky’s “new principle” (1924) of the importance of symbiogenesis in the evolutionary process of at least 2000 million years of life on Earth is correct. The widely touted but undocumented explanation of the origin of evolutionary novelty by “gradual accumulation of random mutations” will be …
Hans Ris (1914-2004). Genophore, Chromosomes And The Bacterial Origin Of Chloroplasts, Lynn Margulis
Hans Ris (1914-2004). Genophore, Chromosomes And The Bacterial Origin Of Chloroplasts, Lynn Margulis
Lynn Margulis (1938 - 2011)
No abstract provided.
Review Of Irwin M. Brodo, Sylvia Duran Sharnoff, Stephen Sharnoff: Lichens Of North America, Lynn Margulis
Review Of Irwin M. Brodo, Sylvia Duran Sharnoff, Stephen Sharnoff: Lichens Of North America, Lynn Margulis
Lynn Margulis (1938 - 2011)
No abstract provided.
Review Of Frank Ryan: Tuberculosis: The Greatest Story Never Told, Lynn Margulis
Review Of Frank Ryan: Tuberculosis: The Greatest Story Never Told, Lynn Margulis
Lynn Margulis (1938 - 2011)
No abstract provided.
Canaleparolina Darwiniensis, Gen. Nov., Sp. Nov., And Other Pillotinaceae Spirochetes From Insects, Andrew Wier, Jon Ashen, Lynn Margulis
Canaleparolina Darwiniensis, Gen. Nov., Sp. Nov., And Other Pillotinaceae Spirochetes From Insects, Andrew Wier, Jon Ashen, Lynn Margulis
Lynn Margulis (1938 - 2011)
We describe two new pillotinaceous spirochetes (Canaleparolina darwiniensis, Diplocalyx cryptotermitidis) and identify for the first time Hollandina pterotermitidisfrom both the subterranean termite Cryptotermes cavifrons and the wood-eating cockroach Cryptocercus punctulatus based on morphometric analysis of transmission electron micrographic thin sections. C. darwiniensis, gen. nov., sp. nov., limited to near Darwin, Australia, invariably is present on the surface of the treponeme-studded trichomonad Mixotricha paradoxa, a consistent inhabitant of the hindgut of healthy termite Mastotermes darwiniensis. The spirochete both attached to the surface of protists and free-swimming in the paunch (hindgut) lumen of the insect has 16 periplasmic flagella (16:32:16) and imbricated …
The Wonderful Lives Of Joseph Leidy, Andrew Wier, Lynn Margulis
The Wonderful Lives Of Joseph Leidy, Andrew Wier, Lynn Margulis
Lynn Margulis (1938 - 2011)
No abstract provided.
Morphogenesis By Symbiogenesis, Michael J. Chapman, Lynn Margulis
Morphogenesis By Symbiogenesis, Michael J. Chapman, Lynn Margulis
Lynn Margulis (1938 - 2011)
Here we review cases where initiation of morphogenesis, including the differentiation of specialized cells and tissues, has clearly evolved due to cyclical symbiont integration. For reasons of space, our examples are drawn chiefly from the plant, fungal and bacterial kingdoms. Partners live in symbioses and show unique morphological specializations that result when they directly and cyclically interact. We include here brief citations to relevant literature where plant, bacterial or fungal partners alternate independent with entirely integrated living. The independent, or at least physically unassociated stages, are correlated with the appearance of distinctive morphologies that can be traced to the simultaneous …
Cosmopolitan Distribution Of The Large Composite Microbial Mat Spirochete, Spirosymplokos Deltaeiberi, Lynn Margulis, Antoni Navarrete, Mónica Solé
Cosmopolitan Distribution Of The Large Composite Microbial Mat Spirochete, Spirosymplokos Deltaeiberi, Lynn Margulis, Antoni Navarrete, Mónica Solé
Lynn Margulis (1938 - 2011)
Inocula from organic-rich black muds immediately underlying intertidal laminated microbial mats dominated by Microcoleus chthonoplastes yielded large, variable diameter spirochetes. These unusual spirochetes, previously reported only from the Alfacs Peninsula at the delta of the Ebro river in northeast Spain, contain striking arrays of cytoplasmic granules packed into their protoplasmic cylinders. On several occasions, both in summer and winter, the huge spirochetes were recognized in samples from mats growing in the Sippewissett salt marsh at Woods Hole Massachusetts. They were also seen in similar samples from microbial mats at North Pond, Laguna Figueroa, Baja California Norte, Mexico. The identity of …
Do Prokaryotes Contain Microtubules?, Lynn Margulis, D. Bermudes, G. Hinkle
Do Prokaryotes Contain Microtubules?, Lynn Margulis, D. Bermudes, G. Hinkle
Lynn Margulis (1938 - 2011)
In eukaryotic cells, microtubules are 24-nm-diameter tubular structures composed of a class of conserved proteins called tubulin. They are involved in numerous cell functions including ciliary motility, nerve cell elongation, pigment migration, centrosome formation, and chromosome movement. Although cytoplasmic tubules and fibers have been observed in bacteria, some with diameters similar to those of eukaryotes, no homologies to eukaryotic microtubules have been established. Certain groups of bacteria including azotobacters, cyanobacteria, enteric bacteria, and spirochetes have been frequently observed to possess microtubule-like structures, and others, including archaebacteria, have been shown to be sensitive to drugs that inhibit the polymerization of microtubules. …
Composite, Large Spirochetes From Microbial Mats: Spirochete Structure Review, Lynn Margulis, J. B. Ashen, M. Solé, R. Guerrero
Composite, Large Spirochetes From Microbial Mats: Spirochete Structure Review, Lynn Margulis, J. B. Ashen, M. Solé, R. Guerrero
Lynn Margulis (1938 - 2011)
Phenomena previously unknown in free-living spirochetes are reported: large-sized cells with variable diameter (length to 100 microns, width between 0.4 and 3.0 microns), composite structure (smaller spirochetes inside larger ones), and positive phototropic behavior. These bacteria, Spirosymplokos, are compared with all other spirochete genera. The large spirochete, grown in mixed culture, was studied live and by transmission EM. The protoplasmic cylinder was replete with spherical granules 20-32 nm in diameter, and three to six periplasmic 26-nm flagella were inserted subterminally. Comparably granulated and flagellated small spirochetes were located inside the protoplasmic cylinder and in the periplasm of the large ones. …
Words As Battle Cries: Symbiogenesis And The New Field Of Endocytobiology, Lynn Margulis
Words As Battle Cries: Symbiogenesis And The New Field Of Endocytobiology, Lynn Margulis
Lynn Margulis (1938 - 2011)
No abstract provided.
Predatory Prokaryotes: Predation And Primary Consumption Evolved In Bacteria, Lynn Margulis, Ricardo Guerrero, Carlos Pedrós-Alió, Isabel Esteve, Jordi Mas, David Chase
Predatory Prokaryotes: Predation And Primary Consumption Evolved In Bacteria, Lynn Margulis, Ricardo Guerrero, Carlos Pedrós-Alió, Isabel Esteve, Jordi Mas, David Chase
Lynn Margulis (1938 - 2011)
Two kinds of predatory bacteria have been observed and characterized by light and electron microscopy in samples from freshwater sulfurous lakes in northeastern Spain. The first bacterium, named Vampirococcus, is Gram-negative and ovoidal (0.6 μm wide). An anaerobic epibiont, it adheres to the surface of phototrophic bacteria (Chromatium spp.) by specific attachment structures and, as it grows and divides by fission, destroys its prey. An important in situ predatory role can be inferred for Vampirococcus from direct counts in natural samples. The second bacterium, named Daptobacter, is a Gram-negative, facultatively anaerobic straight rod (0.5 × 1.5 μm) with a single …
Microbial Communities, Lynn Margulis, David Chase, Ricardo Guerrero
Microbial Communities, Lynn Margulis, David Chase, Ricardo Guerrero
Lynn Margulis (1938 - 2011)
No abstract provided.
Evidence That The Synchronized Production Of New Basal Bodies Is Not Associated With Dna Synthesis In Stentor Coeruleus, K. B. Younger, S. Banerjee, J. K. Kelleher, M. Winston, Lynn Margulis
Evidence That The Synchronized Production Of New Basal Bodies Is Not Associated With Dna Synthesis In Stentor Coeruleus, K. B. Younger, S. Banerjee, J. K. Kelleher, M. Winston, Lynn Margulis
Lynn Margulis (1938 - 2011)
Stentors were induced to produce synchronously thousands of new ciliated oral membranellar band basal bodies in less than 3 h. DNA synthesis does not accompany this process, as determined by [3H]thymidine incorporation into isolated bands and by sensitivity to DNA synthesis inhibitors (mitomycin C, ethidium bromide, cytosine arabinoside and hydroxyurea). Yet DNA could be detected in the cortex and the band at basal body sites by autoradiography. Since [3H]thymidine incorporation into membranellar band was eliminated in concentrations of ethidium bromide that had no effect on basal body formation, the previous reports of ciliate kinetosomal (basal body) DNA are interpreted as …
New Phylogenies Of The Lower Organisms: Possible Relation To Organic Deposits In Precambrian Sediment, Lynn Margulis
New Phylogenies Of The Lower Organisms: Possible Relation To Organic Deposits In Precambrian Sediment, Lynn Margulis
Lynn Margulis (1938 - 2011)
Classical phylogenies of the lower organisms are based on assumptions recently claimed to be erroneous. Alternative assumptions, more consistent with modern genetic and biochemical data, lead to the construction of new phylogenies. The new phylogenies (one for prokaryote organisms and one for eukaryotes) based on the symbiotic theory of the origin of eukaryotic organelles predict the nature and sequence of organic deposits on the Precambrian earth. Even if incorrect, these phylogenies present a modern framework upon which to compare the many recent reports of organic remains in sediment.