scholarly journals A simplified correlation between vertebrate evolution and Paleozoic geomagnetism

2019 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Evolutionary Patterns ◽  
Geologic Time Scale ◽  
Polarity Reversals ◽  
Low Levels ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups ◽  
Biologic Factors

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent paleobiology databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tends to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, climate alteration, low-frequency electromagnetic fields, depletion of ozone, the stripping of atmospheric oxygen, and increasing production of Carbon14 in the stratosphere have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet showing the first appearance of 2104 genera with each genus assigned to one of 8 major taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, 727 Paleozoic vertebrates represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic and sampling biases, the resulting Pearson’s correlation coefficient between the 727 genera and geomagnetic polarity zones equals 0.8, a result that suggests a strong relationship exists between Paleozoic vertebrates and geomagnetism. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrates become immune to the ongoing effects of polarity reversals?

scholarly journals A simplified correlation between vertebrate evolution and Paleozoic geomagnetism

2019 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Evolutionary Patterns ◽  
Geologic Time Scale ◽  
Polarity Reversals ◽  
Low Levels ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups ◽  
Biologic Factors

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent paleobiology databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tends to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, climate alteration, low-frequency electromagnetic fields, depletion of ozone, the stripping of atmospheric oxygen, and increasing production of Carbon14 in the stratosphere have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet showing the first appearance of 2210 age-dated genera with each genus assigned to one of eleven major taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, 737 Paleozoic vertebrates represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic and sampling biases, the resulting Pearson’s correlation coefficient between the 737 genera and geomagnetic polarity zones equals 0.89. These results suggest a strong relationship exists between Paleozoic vertebrates and geomagnetism. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrates become immune to the ongoing effects of polarity reversals?

scholarly journals A simplified correlation between vertebrate evolution and Paleozoic geomagnetism

2019 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Evolutionary Patterns ◽  
Geologic Time Scale ◽  
Polarity Reversals ◽  
Low Levels ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups ◽  
Biologic Factors

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent paleobiology databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tends to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, climate alteration, low-frequency electromagnetic fields, depletion of ozone, the stripping of atmospheric oxygen, and increasing production of Carbon14 in the stratosphere have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet showing the first appearance of 2210 age-dated genera with each genus assigned to one of eleven major taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, 737 Paleozoic vertebrates represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic and sampling biases, the resulting Pearson’s correlation coefficient between the 737 genera and geomagnetic polarity zones equals 0.89. These results suggest a strong relationship exists between Paleozoic vertebrates and geomagnetism. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrates become immune to the ongoing effects of polarity reversals?

scholarly journals A simplified correlation between vertebrate evolution and Paleozoic geomagnetism

2019 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Evolutionary Patterns ◽  
Geologic Time Scale ◽  
Polarity Reversals ◽  
Low Levels ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups ◽  
Biologic Factors

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent paleobiology databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tends to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, climate alteration, low-frequency electromagnetic fields, depletion of ozone, the stripping of atmospheric oxygen, and increasing production of Carbon14 in the stratosphere have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet showing the first appearance of 2210 age-dated genera with each genus assigned to one of eleven major taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, 737 Paleozoic vertebrates represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic and sampling biases, the resulting Pearson’s correlation coefficient between the 737 genera and geomagnetic polarity zones equals 0.89. These results suggest a strong relationship exists between Paleozoic vertebrates and geomagnetism. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrates become immune to the ongoing effects of polarity reversals?

scholarly journals Paleozoic geomagnetism shapes vertebrate evolution

2018 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Age Dating ◽  
P Value ◽  
Evolutionary Patterns ◽  
Natural Group ◽  
Polarity Reversals ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tend to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, weather alteration, low-frequency electromagnetic fields, depletion of ozone, and the stripping of atmospheric oxygen have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet that shows the first appearance of 1809 age-dated genera with each genus assigned to one of 28 taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, we counted 508 Paleozoic vertebrates that first appeared within 20 million-years of the origin of their clade or natural group. These genera represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic biases, the resulting Pearson’s coefficient between these genera and polarity zones equals 0.781. Using 11 commonly accepted clades and assuming a natural competition existed between them, we counted each genus from a clade’s inception until it was bypassed by a subsequent clade. Here, Pearson's equals 0.901 with a p-value of <0.000001. In a blindfold study, we separated the Paleozoic into a dozen equally-sized temporal bins, then 13 bins, up to 31 bins. The mean Pearson coefficient for these bins is 0.810. After calculating coefficients for four distinct taxonomies, two paleomagnetic systems, three systematics for age-dating within geologic stages, and seven independent spreadsheets, the results suggest a strong relationship exists between Paleozoic vertebrates and polarity reversals. In addition, the earliest species of the major divisions of Paleozoic vertebrates (jawless fish, armored fish, jawed fish, cartilage fish, fish with bones, lobe-finned fish, tetrapods, amphibians, reptiles, and synapsids) first appeared in zones with relatively high levels of polarity reversals. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrate families become immune to the ongoing effects of polarity reversals?

scholarly journals Paleozoic geomagnetism shapes vertebrate evolution

2018 ◽  
Author(s):  
John P Staub
Keyword(s):  
Atmospheric Oxygen ◽  
Low Frequency ◽  
Strong Relationship ◽  
Age Dating ◽  
P Value ◽  
Evolutionary Patterns ◽  
Natural Group ◽  
Polarity Reversals ◽  
Geomagnetic Polarity ◽  
Taxonomic Groups

Background. Despite a fifty-year failure of paleontologists to find a viable connection between geomagnetic polarity reversals and evolutionary patterns, recent databases show that the early appearance, radiation, and diversification of Paleozoic vertebrates tend to occur during periods having frequent collapses of the Earth’s geomagnetic field. The transition time during the collapse of the Earth’s protective magnetic shield can last thousands of years, and the effects on biota are unknown. Solar and cosmic radiation, volcanism, weather alteration, low-frequency electromagnetic fields, depletion of ozone, and the stripping of atmospheric oxygen have been proposed as possible causes, but previous studies have found no effects. Methods. Using published databases, we compiled a spreadsheet that shows the first appearance of 1809 age-dated genera with each genus assigned to one of 28 taxonomic groups. From Gradstein’s Geologic Time Scale 2012, we delineated 17 Paleozoic zones with either high or low levels of polarity reversals. Results. From our compilation, we counted 508 Paleozoic vertebrates that first appeared within 20 million-years of the origin of their clade or natural group. These genera represent the initial radiation and diversification of individual Paleozoic vertebrate clades. After compensating for sample-size and external geologic biases, the resulting Pearson’s coefficient between these genera and polarity zones equals 0.781. Using 11 commonly accepted clades and assuming a natural competition existed between them, we counted each genus from a clade’s inception until it was bypassed by a subsequent clade. Here, Pearson's equals 0.901 with a p-value of <0.000001. In a blindfold study, we separated the Paleozoic into a dozen equally-sized temporal bins, then 13 bins, up to 31 bins. The mean Pearson coefficient for these bins is 0.810. After calculating coefficients for four distinct taxonomies, two paleomagnetic systems, three systematics for age-dating within geologic stages, and seven independent spreadsheets, the results suggest a strong relationship exists between Paleozoic vertebrates and polarity reversals. In addition, the earliest species of the major divisions of Paleozoic vertebrates (jawless fish, armored fish, jawed fish, cartilage fish, fish with bones, lobe-finned fish, tetrapods, amphibians, reptiles, and synapsids) first appeared in zones with relatively high levels of polarity reversals. Discussion. The question: is this apparent connection between geomagnetism and the evolution of Paleozoic vertebrate due to environmental or biologic factors. If biologic, why are vertebrates the only biota effected? And after an indeterminate period of time, how do vertebrate families become immune to the ongoing effects of polarity reversals?

Earth’s Middle Ages: What Came after the GOE

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Middle Ages ◽  
Atmospheric Oxygen ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Dissolved Iron ◽  
Great Oxidation Event ◽  
Low Levels ◽  
Substantial Rise

This chapter considers the aftermath of the great oxidation event (GOE). It suggests that there was a substantial rise in oxygen defining the GOE, which may, in turn have led to the Lomagundi isotope excursion, which was associated with high rates of organic matter burial and perhaps even higher concentrations of oxygen. This excursion was soon followed by a crash in oxygen to very low levels and a return to banded iron formation deposition. When the massive amounts of organic carbon buried during the excursion were brought into the weathering environment, they would have represented a huge oxygen sink, drawing down levels of atmospheric oxygen. There appeared to be a veritable seesaw in oxygen concentrations, apparently triggered initially by the GOE. The GOE did not produce enough oxygen to oxygenate the oceans. Dissolved iron was removed from the oceans not by reaction with oxygen but rather by reaction with sulfide. Thus, the deep oceans remained anoxic and became rich in sulfide, instead of becoming well oxygenated.

Allometry of diving capacity in air-breathing vertebrates

1997 ◽  
Vol 75 (3) ◽  
pp. 339-358 ◽  
Author(s):  
Jason F. Schreer ◽  
Kit M. Kovacs
Keyword(s):  
Body Mass ◽  
Marine Mammals ◽  
Strong Relationship ◽  
Allometric Relationship ◽  
Air Breathing ◽  
Diving Depth ◽  
Maximum Duration ◽  
Phocid Seals ◽  
Bird Group ◽  
Taxonomic Groups

Maximum diving depths and durations were examined in relation to body mass for birds, marine mammals, and marine turtles. There were strong allometric relationships between these parameters (log10 transformed) among air-breathing vertebrates (r = 0.71, n = 111 for depth; r = 0.84, n = 121 for duration), although there was considerable scatter around the regression lines. Many of the smaller taxonomic groups also had a strong allometric relationship between diving capacity (maximum depth and duration) and body mass. Notable exceptions were mysticete cetaceans and diving/flying birds, which displayed no relationship between maximum diving depth and body mass, and otariid seals, which showed no relationship between maximum diving depth or duration and body mass. Within the diving/flying bird group, only alcids showed a significant relationship (r = 0.81, n = 9 for depth). The diving capacities of penguins had the highest correlations with body mass (r = 0.81, n = 11 for depth; r = 0.93, n = 9 for duration), followed by those of odontocete cetaceans (r = 0.75, n = 21 for depth; r = 0.84, n = 22 for duration) and phocid seals (r = 0.70, n = 15 for depth; r = 0.59, n = 16 for duration). Mysticete cetaceans showed a strong relationship between maximum duration and body mass (r = 0.84, n = 9). Comparisons across the various groups indicated that alcids, penguins, and phocids are all exceptional divers relative to their masses and that mysticete cetaceans dive to shallower depths and for shorter periods than would be predicted from their size. Differences among groups, as well as the lack of relationships within some groups, could often be explained by factors such as the various ecological feeding niches these groups exploit, or by variations in the methods used to record their behavior.

Cold tolerance of the Antarctic springtail Gomphiocephalus hodgsoni (Collembola, Hypogastruridae)

2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen
Keyword(s):  
Cold Tolerance ◽  
Thermal Environment ◽  
Strong Relationship ◽  
Dry Weight ◽  
Glycerol Content ◽  
Recrystallization Inhibition ◽  
Low Levels ◽  
Inhibition Studies ◽  
The Antarctic ◽  
The Relationship

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.

Tinnitus: some thoughts about its origin

1984 ◽  
Vol 98 (S9) ◽  
pp. 31-37 ◽  
Author(s):  
J. J. Eggermont
Keyword(s):  
Hair Cells ◽  
High Frequency ◽  
Basilar Membrane ◽  
Stimulus Frequency ◽  
Low Frequency ◽  
Nerve Fibers ◽  
Ear Ossicles ◽  
Stimulus Transduction ◽  
Low Levels ◽  
Inner Ear Fluids

An auditory sensation follows generally as the result of the sequence stimulus, transduction, coding, transformation and sensation. This is then optionally followed by perception and a reaction. The stimulus is usually airborne sound causing movements of the tympanic membrane, the middle ear ossicles, the inner ear fluids and the basilar membrane. The movements of the basilar membrane are dependent on stimulus frequency: high frequency tones excite only the basal part of the cochlea, regardless of the stimulus intensity; low frequency tones at low levels only excite the so-called place specific region at the apical end but at high levels (above 60–70 dB SPL) cause appreciable movement of the entire basilar membrane. Basilar membrane tuning is as sharp as that of inner hair cells or auditory nerve fibers (Sellick et al., 1982) at least in the basal turn of animals that have a cochlea in physiologically impeccable condition.

scholarly journals Patterns of EEG Activity in Individuals with Autism Spectrum Disorders

2016 ◽  
Vol 21 (3) ◽  
pp. 47-55
Author(s):  
M.A. Zhukova
Keyword(s):  
Autism Spectrum Disorders ◽  
Neural Activity ◽  
Low Frequency ◽  
Strong Relationship ◽  
Autism Spectrum ◽  
Semantic Integration ◽  
Adults With Autism ◽  
Eeg Activity ◽  
Spectrum Disorders ◽  
Cortical Regions

The article reviews most recent findings on neural activity in children and adults with autism spectrum disorders (ASD). Most of the studies demonstrate decreased connectivity in cortical regions, excitatory/inhibitory imbalance and atypical processing of language in people with ASD. It is argued that difficulties in semantic integration are connected to selective insensitivity to language, which is manifested in atypical N400 ERP component. In the article we analyze the data suggesting a strong relationship between ASD and epilepsy and argue that the comorbidity is more prevalent among individuals who have cognitive dysfunction. The EEG profile of people with ASD suggests U-shaped alterations with excess in high- and low-frequency EEG bands. We critically analyze the “broken mirror” hypothesis of ASD and demonstrate findings which challenge this theory.

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