scholarly journals Paleozoic geomagnetism shapes vertebrate evolution

Author(s):  
John P Staub

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?

2018 ◽  
Author(s):  
John P Staub

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?


2019 ◽  
Author(s):  
John P Staub

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?


2019 ◽  
Author(s):  
John P Staub

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?


2019 ◽  
Author(s):  
John P Staub

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?


2019 ◽  
Author(s):  
John P Staub

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?


1997 ◽  
Vol 75 (3) ◽  
pp. 339-358 ◽  
Author(s):  
Jason F. Schreer ◽  
Kit M. Kovacs

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.


Author(s):  
Siew Bee Aw ◽  
Bor Tsong Teh ◽  
Gabriel Hoh Teck Ling ◽  
Pau Chung Leng ◽  
Weng Howe Chan ◽  
...  

This paper attempts to ascertain the impacts of population density on the spread and severity of COVID-19 in Malaysia. Besides describing the spatio-temporal contagion risk of the virus, ultimately, it seeks to test the hypothesis that higher population density results in exacerbated COVID-19 virulence in the community. The population density of 143 districts in Malaysia, as per data from Malaysia’s 2010 population census, was plotted against cumulative COVID-19 cases and infection rates of COVID-19 cases, which were obtained from Malaysia’s Ministry of Health official website. The data of these three variables were collected between 19 January 2020 and 31 December 2020. Based on the observations, districts that have high population densities and are highly inter-connected with neighbouring districts, whether geographically, socio-economically, or infrastructurally, tend to experience spikes in COVID-19 cases within weeks of each other. Using a parametric approach of the Pearson correlation, population density was found to have a moderately strong relationship to cumulative COVID-19 cases (p-value of 0.000 and R2 of 0.415) and a weak relationship to COVID-19 infection rates (p-value of 0.005 and R2 of 0.047). Consequently, we provide several non-pharmaceutical lessons, including urban planning strategies, as passive containment measures that may better support disease interventions against future contagious diseases.


2020 ◽  
Vol 10 (3) ◽  
pp. 200-204
Author(s):  
Sana Akbar ◽  
Misbah Riaz ◽  
Lalarukh Munawar ◽  
Shazia Shakoor

Objective: The purpose of this study was to correlate the hypochondriacal concerns related to diseases with level of anxiety and depression symptoms among medical and engineering undergraduates. Study design and Setting: Cross sectional study was conducted among undergraduates of final year students of BUMDC (Bahria University Medical & Dental College) and engineering students from NUST- PNEC (NUST – Pakistan Navy Engineering College). Methodology: In this study; (99) final year medical students and (92) engineering students were recruited. In order to maintain consistency of age, students aging between 21–26 years were selected. Selected students were handed to fill the required ‘Self-administered Questionnaire’ comprising of demographic details, short health anxiety inventory, medical history and DASS (depression, anxiety and stress scale) which were completed on-site. Data was entered in SPSS version 21 and analyzed using Fisher’s exact test. P value < 0.05 was considered as statistically significant. Result: Out of 191 students in total from both the groups n=86 (45%) were females and n=105(55%) were males. There were 99 participants from MBBS and 92 from engineering. The participants’ ages ranged from 21-26 years with a mean= 23.95 (SD±2.29), both the cohorts belonged to approximately same age group. While assessing depression the responses were not very different for both the groups. When responses of depression scale were related to visits to psychiatrists or psychologist or psychotherapist a strong relationship was observed (p=0.012) in medical students cohort. Conclusion: The results of the study reflected comparable psychosocial strain at an elevated level among both student groups


2016 ◽  
Vol 21 (3) ◽  
pp. 47-55
Author(s):  
M.A. Zhukova

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.


2021 ◽  
Vol 17 (35) ◽  
pp. 203
Author(s):  
Benson Muchoki Mwangi ◽  
Francis N. Kibera ◽  
Mary Kinoti ◽  
Magutu P. Obara

This paper focuses on determining the influence of sales territory design on salesforce performance in the detergent manufacturing companies in Kenya. Detergents play a critical role in our everyday lives by ensuring hygiene at our personal level, in our homes, in schools, institutions, and hospitals. Detergents have gained a lot of prominence since the onset of the Corona Virus (COVID-19) disease in 2019, as it has been proved that they play an important role in curtailing the transmission of the COVID-19 disease. The Salesforce plays an important role in organizations as they are the ones who in most cases interact with customers, provide information about their organization and products, provide prices, demonstrate how products are used, train customers, provide after sales service, and resolve any issues that may arise. The study was anchored on Expectancy Theory, Resource Based Theory, Equity Theory, and Agency Theory. The study adopted positivism philosophy and used a descriptive cross sectional design. The unit of analysis was the sales people in the detergent manufacturing companies in Kenya who are members of Kenya Association of Manufacturers as per list obtained from KAM in December 2018. The study used primary data which was collected by administering semi-structured questionnaires. The data was analyzed using a combination of both descriptive and inferential statics to describe the manifestations of the variables in the data collected, simple regression model was used to test the significance of the influence of sales territory design (independent variable) on the salesforce performance (dependent variable). Fischer distribution test (F-test) was used to test the significance of the independent variable and the overall model. The p-value for the F-statistic was used to determine the robustness of the model. This was done at 95% confidence level (p<0.05). The study found a strong relationship between sales territory design and salesforce performance. This depicts that sales territory design is critical in determining salesforce performance in detergent manufacturing companies in Kenya.


Sign in / Sign up

Export Citation Format

Share Document