McPherson College
  • McPherson, United States
Recent publications
The study of single cases has occupied an important position in the history of the human sciences and William Stephenson (1902–1989) has been explicit that the study of single cases from the centrality-of-self standpoint is the only way to proceed scientifically. Adopting the view that abductions, like laws, are for future use and provide guidance in helping determine what to look for and which facts have value within any domain of inquiry, this study focuses on what solitude means in individual cases. Two persons reflect on their own experiences under nine conditions of instruction inspired by various laws of subjectivity that have been proposed by Stephenson, and the factor-analytic results are used to illustrate various of the laws as well as the variety in individual lives, and to elucidate the importance of the intensive study of single cases.
Caenorhabditis elegans are members of the nematode family and have been used as model organisms of epigenetic studies for many years. C. elegans have a relatively short life cycle; the worms grow from an egg to an adult within the span of about 3-4 days and an overall lifespan of about 2-3 weeks. The worms are very easy to maintain, requiring for survival only nematode growth medium (NGM) agar plates that are kept at a temperature of about 20-25 C and contain E. coli for food. For this study, which replicates aspects of a study reported by Kishimoto et al. (2017), C. elegans was used to explore the epigenetic effects of stress on longevity. The animals in this study that were subjected to the environmental stressor starvation showed an increase in overall lifespan based on the statistical analysis of a Kaplan-Meier Survivorship test. This increased survival rate was also found to be passed to at least three subsequent generations who were grown under unstressed conditions. These results showcase the hormetic epigenetic effects of starvation in C. elegans.
The evolution of complex signals has often been explored by testing multiple functional hypotheses regarding how independent signal components provide selective benefits to offset the costs of their production. In the present study, we take a different approach by exploring the function of complexity per se. We test the hypothesis that increased vibratory signal complexity-based on both proportional and temporal patterning-provides selective benefits to courting male Schizocosa stridulans wolf spiders. In support of this hypothesis, all of our quantified metrics of vibratory signal complexity predicted the mating success of male S. stridulans. The rate of visual signalling, which is mechanistically tied to vibratory signal production, was also associated with mating success. We additionally found evidence that males can dynamically adjust the complexity of their vibratory signalling. Together, our results suggest that complexity per se may be a target of female choice.
Animals often communicate in complex, heterogeneous environments, leading to hypothesized selection for increased detectability or discriminability in signaling traits. The extent to which secondary sexual ornaments have evolved to overcome the challenges of signaling in complex environments, however, remains understudied, especially in comparison to their role as indicator traits. This study tested the hypothesis that the condition-dependent secondary sexual ornamentation in the wolf spider Rabidosa rabida functions to increase detectability/discriminability in visually complex environments. We predicted that male ornamentation would interact with the complexity of the signaling environment to affect male mating success. In particular, we expected ornaments to confer a greater mating advantage when males courted in visually complex environments. To test this, we artificially manipulated male foreleg ornamentation (present/absent) and ran repeated-measures mating trials across laboratory microcosms that represented simple versus complex visual signaling environments. Microcosm visual complexity differed in their background pattern, grass stem color, and grass stem placement. We found that ornamented males mated more often and more quickly than unornamented males across both environments, but we found no support for an ornament-by-environment interaction. Male courtship rate, however, did interact with the signaling environment. Despite achieving the same level of mating success across signaling environments, ornamented males courted less rapidly in complex versus simple environments, although environmental complexity had no influence on unornamented male courtship rates. Our results suggest that the visual complexity of the signaling environment influences the interactive influence of ornamentation and dynamic visual courtship on female mate choice.
Temperature affects nearly all of life's processes. Ectothermic animals living in temperate regions are subjected to dramatic daily shifts in temperature that force them to adapt in a variety of ways. The Dotted Wolf Spider (Rabidosa punctulata) mates during fall, which leaves this species vulnerable to temperature swings that can impact their reproductive success. In this study, we manipulated temperature in a controlled laboratory experiment to examine how the mating behaviors of both sexes of R. punctulata are affected in cold (4.4C) and warm (26.74C) environments. Overall, the species seems well acclimated to colder environments. While these spiders were slower to begin moving in the cold, they spent an equal percentage of the trial in motion across both temperature treatments. Males were less likely to adopt any mating behaviors in the cold, and overall pairs were significantly less likely to mate in the cold. However, males were able to successfully mount and at least two males were able to copulate in the near freezing temperatures. Directly mounting females without prior courtship was the most successful mating tactic regardless of temperature, and there was a trend suggesting males were more likely to forgo courtship and use direct mounting when interacting with females in the cold. This study highlights the amazing flexibility in reproductive tactics that enable mating success in R. punctulata despite experiencing cold temperatures in their fall mating season.
Males and females have conflicting interests on the frequency and outcomes of mating interactions. Males maximize their fitness by mating with as many females as possible, while choosy females often reduce receptivity following copulation. Alternative male mating tactics can be adaptive in their expression to a variety of mating contexts, including interactions with a relatively unreceptive mated female. Male Rabidosa punctulata wolf spiders can adopt distinctive mating tactics when interacting with a female, a complex courtship display, and/or a more coercive direct mount tactic that often involves grappling with females for copulation. In this study, we set up female mating treatments with initial trials and then paired mated and unmated females with males to observe both female remating frequencies and the male mating tactics used during the interactions. Males adopted different mating tactics depending on the mating status of the female they were paired with. Males were more likely to adopt a direct mount tactic with already-mated females and courtship with unmated females. Already-mated females were considerably less receptive to males during experimental trials, although they did remate 34% of the time, the majority of which were with males using a direct mount tactic. While males adjusting to these contextual cues were able to gain more copulations, the observation of multiple mating in female R. punctulata introduces the potential for sperm competition. We discuss this sexual conflict in terms of the fitness consequences of these mating outcomes for both males and females.
The study was conducted to determine the putative pharmacokinetic and toxicological properties of naphthalene and its derivatives, hence determining their harmful effects, if any in the normal daily function of the human system. The effects of these compounds on hormonal homeostasis and the endocrine system were also evaluated. The pharmacokinetic ADMET (Absorption, distribution, metabolism, excretion, and toxicity) properties were determined by running a computer-simulated prediction on the compounds based on their canonical SMILES (Simplified Molecular Input Line Entry System) structure using the pkCSM online prediction tool. The Canonical SMILES structures were obtained from the PubChem database. The predictive endocrine disruption potential was evaluated using the Endocrine Predictome computational tool which uses a molecular docking system to predict the interaction between the investigated chemicals and the affected nuclear receptors. The results showed that naphthalene and the derivatives have relatively high log P values, implying their respective lipophilicity; however, only naphthalene-1,2,6,7-tetrol could not permeate the blood-brain barrier. Moreover, all the selected compounds are substrates of the P-glycoprotein and do not inhibit their activity. The results also indicated that naphthalene and all four selected derivatives could have an inhibitory effect on the CYP1A2 enzyme and a disruptive effect on some endocrine functions due to their respective high binding affinity with endocrine receptors. In conclusion, the study showed that naphthalene and the derivatives could have adverse effects on the physiological function of the body vis-à-vis neurological damages, and various metabolic disorders. The predictive influence on the endocrine system also indicated the selected chemicals could induce detrimental changes in endocrine functions.
Ethanol is a multifunctional compound that has many uses and can be made naturally by sugar-fermenting yeast such as Saccharomyces cerevisiae. However, ethanol is toxic to yeast, so in this study we aimed to improve yeast ethanol tolerance, which could result in greater efficiencies in the process of alcohol production. This research explores the effectiveness of artificially inducing population-level variation through the application of ethyl methanesulfonate (EMS) on increasing the ethanol tolerance in S. cerevisiae. After several rounds of selection and increasing ethanol concentrations, ranging from 9-27%, the two treatment populations (AS - Artificial Selection only; and EMS – Exposure to EMS and Artificial Selection) were compared to the initial parental population. The parental strain was tolerant to ethanol concentrations of 13%, while the AS treatment was tolerant to slightly higher levels, 16%. Both of these treatments were well below the EMS treatment which expressed a tolerance of 27%. To test differences between strains, the parental strain, selection strain, and the EMS-exposed strain were separately plated on ten 27% ethanol plates and ten 0% ethanol plates, and growth was checked after 24 hours. The EMS-exposed strain was the only strain that grew at 27% ethanol; all strains grew at 0% ethanol. These results show that EMS, artificial selection, and ethanol as a stressor might be effective in producing strains of S. cerevisiae that are able to produce greater amounts of ethanol before toxicity sets in.
J. R. Kantor introduced his interbehavioral psychology or interbehaviorism in the early 20th century. One major mark of interbehaviorism is the view of psychological behavior as mutually interdependent functions of stimulus objects and response occurrences. In this, the foundations of any behavior are represented by stimulus ↔ response. This paper explores the similarities between Kantor’s stimulus-response interaction and Dewey’s (1896) sensori-motor circuit, which was his proposed alternative to the reflex arc. The paper begins by discussing Kantor’s (1917) dissertation at the University of Chicago as a functional study of the verbal behavior of philosophers. It then examines Dewey’s (1896) sensori-motor circuit and critique of the reflex arc. Afterward, it describes Kantor’s concepts of stimulus function and response function. Lastly, it brings together Kantor and Dewey, juxtaposing their positions. The paper concludes by putting Kantor and Dewey in context, considering the importance of stimulus ↔ response for the science of psychology.
This chapter proposes that the Fourth Gospel was written by an early church leader named John, different from the Apostle John. This John, who later became an elder in the church at Ephesus (and is hence known as John the Elder), was likely a Sadducean priest in the Jerusalem Temple and an eyewitness to those events in Jesus’ ministry that occurred during Jesus’ festival visits to Jerusalem. He may well have owned the house where the Last Supper was eaten. The Gospel of John was written between 85 ce and 90 ce. I conclude by explaining how these hypotheses may stimulate future research into the relationships between the Fourth Gospel and eyewitness testimony and between the Fourth Gospel and the Temple establishment.
The theses proposed in this book open up exciting new vistas for historical, theological, and philosophical research on the Gospel of John. I shall draw together the threads of the book’s importance for scholarship in each of these areas.
I propose that the Fourth Gospel presents the Holy Spirit as a divine person, not an impersonal force, alongside of God the Father and Jesus himself. For John, the Spirit is ontologically equal but functionally subordinate to both God the Father and Jesus. This claim is made evident in Jesus’ discourse at the Last Supper. Hence John furnishes what may be styled a proto-Trinitarianism. These suppositions have the potential to prompt Johannine scholars into new explorations of the Fourth Gospel’s pneumatology and role in shaping proto-orthodoxy.
The Johannine phrase “to believe in him (Jesus)” (πιστεύω εἰς αὐτὸν) is often taken today as denoting assent to various propositions about Jesus. However, I argue that John crafts this phrase to mean something far more profound. Using the wedding at Cana as a foil, John takes πιστεύω εἰς αὐτὸν as synonymous with pledging one’s allegiance to Jesus by making a personal commitment that amounts to spiritual marriage. The theses in this chapter have the potential to spark future research on the relationship between the Fourth Gospel and its possible reception through the theme of spiritual marriage in the history of Christian mysticism and of the sixteenth-century Reformations.
This chapter argues that the Gospel of John is literarily independent from the Synoptic Gospels. The Fourth Gospel was addressed to a Gentile audience in Ephesus. As an eyewitness account, it uses as its only literary source a precursor Gospel—the Signs Source—also written by John the Elder but addressed to a Jewish audience in Jerusalem before the city’s destruction by the Romans in 70 ce. This chapter reconstructs the Signs Source. I conclude by explaining the value of my proposals for future scholarship on the structure of the Signs Source and the literary similarities between the Signs Source and material distinct to the Fourth Gospel.
Often viewed in Johannine scholarship as an inferior and salvifically impotent intellectual assent to Jesus’ messiahship on the basis of his miracles rather than his Kingdom movement, this chapter argues that “believing in his (Jesus’) name” (πιστεύω εἰς τὸ ὄνομα αὐτοῦ) is equivalent to πιστεύω εἰς αὐτὸν and denotes allegiance to Jesus as the embodiment of Yahweh. In its historical context, I propose that Jesus’ refusal to entrust himself to some who “believed in his name” following his Temple demonstration means not that he refused to bequeath such persons salvation but that he would not give himself over to be the political, military messiah they were longing for amidst their Roman oppression. My proposal has the power to open up questions on the Johannine difference between spiritual and political redemption that directly engage American politics and culture.
This chapter contends that the Fourth Gospel presents Jesus as ontologically equal but functionally subordinate to God the Father. According to John, Jesus shares the divine nature with God the Father while remaining a distinct person from God the Father. The relational, though not ontological, unity between Father and Son is extended by Jesus to all who pledge their allegiance to him and his Kingdom movement. I conclude by explaining the value of my theses for stimulating Johannine scholars, in an interdisciplinary vein, to consider how the application of philosophical categories regarding being, role, and unity might shed new light on the Fourth Gospel.
In John 14:6, I argue that the Johannine Jesus made several extraordinary ontological claims. By calling himself “the way,” Jesus declared himself the embodiment of the spirit of Torah, whose very person comprised the goal to which Torah pointed. By calling himself “the truth,” Jesus asserted that he was the perfect expression of Yahweh. By calling himself “the life,” Jesus maintained that he intrinsically possessed the power of existence. By insisting, “No one comes to the Father except through me,” Jesus claimed to be a person of such importance in the calculus of salvation that all who ever experienced relationship with God as Father from the beginning of the world until his day only did so through Jesus, despite that the vast majority of such persons predated Jesus’ earthly life and so knew nothing about Jesus. A strong case can be made that the historical Jesus uttered the sentiment in John 14:6. Based on the aforementioned exegesis, I will raise questions for future interreligious dialogue between Johannine scholars and scholars of non-Christian religions regarding the possibility, according to the Fourth Gospel and perhaps Jesus himself, that non-Christian religions constitute valid avenues of salvation.
This book provides original and controversial contributions into specific areas of Johannine studies, along with defenses of various traditional theological interpretations of John that are commonly overlooked in New Testament scholarship. Kirk R. MacGregor offers new insights into the authorship of the Fourth Gospel, the content of the underlying Signs Source, the meaning of the phrases “believe in him” and “believe in his name,” Jesus’ claim that Abraham saw his day, the significance of John 14.6, and why the resurrected Jesus upbraided Thomas. MacGregor employs the doctrine of middle knowledge to reconcile the seemingly paradoxical Johannine claims of divine predestination, genuine human freedom, and the universal divine salvific will. He defends the ontological equality but functional subordination of the Johannine Jesus to God the Father as well as the deity and personality of the Holy Spirit as presented by the Gospel of John.
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97 members
Kirk MacGregor
  • Philosophy and Religion
Dustin J. Wilgers
  • Natural Sciences
Bryan D. Midgley
  • Behavioral Sciences
McPherson, United States