Evolution Commons^™

Impacts Of Bacterial Evolution On Host Lethality In Drosophila, Andrew Preston

College of Arts & Sciences Senior Theses

Evolution is the process by which species change their genetic traits, such as the pathogenicity of bacteria, over time in response to changes in their environment. Although the genetic mechanisms underlying many evolutionary processes have been revealed, it is still not well understood how opportunistic pathogens, such as Pseudomonas aeruginosa, become virulent. The overall goal of this thesis is to test the Coincidental Evolution Hypothesis, which proposes that the virulence of opportunistic pathogens evolves coincidentally as a by-product of their interaction with their natural predators. I hypothesized that the virulence of ancestral Pseudomonas aeruginosa changes over time if it co-evolves …

Past And Present Patterns Of Neutral And Adaptive Genetic Diversity In Wild Mandrills (Mandrillus Sphinx), Anna Weber

LSU New Orleans Theses and Dissertations

Although primates have fascinated researchers and the public alike for generations, one species that has remained enigmatic is the mandrill (Mandrillus sphinx), a large Cercopithecine monkey endemic to Central Africa. Mandrills are currently in decline due to bushmeat hunting, urbanization, and habitat loss. Neutral and adaptive genetic diversity are important tools for understanding evolutionary history and future viability, since diversity influences a species’ ability to adapt to a changing environment. However, thus far, minimal genetic information has been available for wild mandrills. Because of the dense vegetation in their tropical forest habitat, studying wild mandrills has proven to …

Vibroacoustic Response Of The Tympanic Membrane To Hyoid-Borne Sound Generated During Echolocation In Bats, Chelsie Snipes

Electronic Theses and Dissertations

The hyoid apparatus in laryngeally echolocating bats forms a mechanical connection between the larynx and auditory bullae and has been hypothesized to transfer the outgoing echolocation call to the middle ear during echolocation call emission. We used µCT data to build models of the hyoid apparatus and middle ear from six species of bats and used finite element modeling (FEM) to measure the vibroacoustic response of the tympanic membrane due to hyoid-borne sound generated during echolocation. We found that hyoid-borne sound in all six species stimulated the eardrum within a range likely heard by bats. Although there were minor differences …

Acetate Metabolism In The Fungal Pathogen Cryptococcus Neoformans, Oly Ahmed

All Dissertations

Cryptococcus neoformans is an environmental basidiomycetous fungus with a worldwide distribution and a wide range of habitats. Inhalation of the desiccated yeasts or spores of C. neoformans often leads to opportunistic pulmonary infections in immunocompromised individuals, and in severe cases causes lethal meningitis following hematogenous dissemination. During infection, depending on the tissue and disease state, the invading fungi experience a range of nutrient microenvironments within the host body. As a result, rapid metabolic adaptations geared towards efficient utilization of carbon sources alternative to glucose become one of the prime determinants of survival and growth for the pathogen. Incidentally, cryptococcal infection …

Unveiling The Ancestral Function Of A Neuroendocrine Regulator, Pou-I/Pit1: Insights From Gene Expression Analysis In The Sea Anemone Nematostella Vectensis, Miguel Agostinho Pina Da Silva

Graduate Theses and Dissertations

Cnidaria (i.e., sea anemones, jellyfish, corals) and Bilateria (i.e., vertebrates, sea stars, fruit flies), are sister groups that diverged around 600 million years ago. Despite the long evolutionary time, many cellular differentiation mechanisms, cell types, tissues and behaviors are conserved. Such as neurons, mechanosensory hair cells, feeding behaviors, peristaltic movements, and sleep. Recent advances in genomics, molecular biology and microscopy have fueled an increased interest in understanding cnidarian nervous and neuroendocrine systems. Understanding the developmental mechanisms and the mode of operation of Cnidarian nervous systems helps to reconstruct the ancestral nervous system of the last common ancestor of Cnidaria and …

The Scaling Method: Body Mass Reconstruction Of East African Hominins, Julianna Rose

Anthropology Undergraduate Honors Theses

This thesis details a series of novel methods developed to estimate body masses of hominin fossils using 3-D point cloud registration software. All analyses were conducted through 3-D modeling software that supported the remote study of five fossil femora from East Africa. The fossil computer models were repeatedly aligned with anatomically modern human femora to determine their scaling relationship with the objective of using the scaling factor of the human references to estimate the body mass of the fossils, on the basis of the femoral head breadth. Body mass estimates obtained through this technique were compared to estimates using more …

Phylogenetic Analysis Of Kdr Mutation Conferring Insecticide Resistance In Culex Tarsalis, Eileen Xue, Darren Zhan, Lena Tang

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Sensing Is A Far Cry From Sentience, Antonio Damasio, Hanna Damasio

Animal Sentience

The hypothesis that plants might be sentient confuses the notion of sentience (or consciousness) with that of sensing. Sentience/consciousness implies feeling, experience, and subjectivity. Sensing does not. Plants can sense/detect and even respond appropriately in the absence of any sentience/consciousness.

Plant Sentience: The Burden Of Proof, Jon Mallatt, David G. Robinson, Michael R. Blatt, Andreas Draguhn, Lincoln Taiz

Animal Sentience

Segundo-Ortin & Calvo’s (2023) target article takes a less speculative and more evidence-based approach to plant sentience than did previous works promoting that idea. However, it retains many of the idea’s longstanding difficulties such as starting from a false dichotomy (plants must be either hardwired or sentient), not accepting the full burden of proof for an extraordinary claim, confusingly redefining accepted cognitive terms, implying cell consciousness, not adopting the most parsimonious explanations for plant behaviors, and downplaying all the counterevidence. We advise rectifying these problems before plant sentience can become a full-fledged scientific domain.

Notes On Lung Development In South African Ghost Frogs (Anura: Heleophrynidae), Jackson R. Phillips, Jens Reissig, Gary Kyle Nicolau

Biology Student Research

Lungs are a prototypical trait of most tetrapods, but some amphibians have become secondarily lungless over evolutionary time. Anuran (frog) tadpoles offer an opportunity to examine lung loss from an evolutionary perspective, because there are many independent instances where lungs are not inflated until adulthood, and so are functionally lost. Lung loss is typically associated with living in fast-flowing streams, and so we examined larval lung development in the stream specialist family Heleophrynidae. We find that one genus, Hadromophryne Van Dijk, 2008, has large lungs as tadpole, while the other genus, Heleophryne Sclater, 1898, has much smaller, stunted lung buds. …

Plant Sentience: "Feeling" Or Biological Automatism?, Andrea Mastinu

Animal Sentience

Sentience refers to the ability of an organism to have subjective experiences such as sensations, emotions and awareness. Whereas some animals, including humans, are widely recognized as sentient, the question of whether plants are sentient is still debated among scientists, philosophers, and ethicists. Over the past 20 years, many scientists such as Trewavas, Baluška, Mancuso, Gagliano, and Calvo have reported interesting discussions about memory, behavior, communication, and intelligence in plants. However, the reported conclusions have not convinced the entire scientific community. In this commentary, I would like to focus on two critical aspects related to sentience: cognition and emotion

Plant Sentience: A Hypothesis Based On Shaky Premises, Carel Ten Cate

Animal Sentience

Plants may produce fascinating behavioural phenomena for which the label ‘cognitive process’ may be applicable, at least by some definitions. Segundo-Ortin & Calvo (2023) base their hypothesis that plants might be sentient on the premise of demonstrated presence of cognitive complexity. However, the way phenomena are ascribed, and how the term ‘cognitive’ is used by Segundo-Ortin & Calvo, deviates from the common practice in studies of animal cognition, implying greater complexity than seems justified. It thus provides a questionable basis for attributing sentience to plants.

"In The Beginning, God Created Atoms", Samiya L. Henry

Undergraduate Research and Scholarship Symposium

Genesis 1:1 states “In the beginning, God created the heavens and the earth.” This is the defining statement in the Bible and acts as the foundation of creation and God’s power in the Christian faith. On the other hand, many scientists believe the Big Bang Theory and the discoveries made in other fields of science solely define the creation of the universe and explain life as we know it, also disproving the Christian creation story and the overall existence of God. However, the exact opposite is true; God is science.

Alone, neither of these concepts (faith and science) fully solve …

Stress: An Adaptive Problem Common To Plant And Animal Science, Özlem Yilmaz

Animal Sentience

It is very hard to determine whether plants have “felt states,” but they do have specific states, such as stress, that depend on sensory input from their environment. Plants do not have neurons or brains, but they do have xylem and phloem, as well as many signalling molecules that are dynamically distributed in their bodies, enabling them to produce systemic responses to environmental stimuli. One common topic in plant and animal science that may or may not prove to involve sentience but that does involve the same molecules is stress.

A New Monotypic Genus And Species From China, Langxie Feti Gen. Et Sp. N. (Scorpiones: Buthidae), Victoria Tang, Qingquan Jia, Leonhard Liu

Euscorpius

A new monotypic genus, Langxie gen. n., is described from Xizang (Tibet), China. The new genus shares an important morphological character with Afrolychas Kovařík, 2019: absence of external accessory denticles (EADs) along the sixth row of median denticles (MDs) on the pedipalp movable finger. Langxie gen. n. is different from Afrolychas in the following aspects: loss of EAD near the proximally enlarged MD within each row (i. e., loss of all EAD on the movable finger; this also distinguishes the new genus from other related genera in the “(Ananteris + Isometrus)” clade (Štundlová et …

What Can Plant Science Learn From Animal Nervous Systems?, Luiz Pessoa

Animal Sentience

I welcome Segundo-Ortin & Calvo’s (2023) call for a rigorous science of plant behavior and physiology. My commentary addresses three points drawn from the literature on animal brains that could help elucidate the possibility of cognition and sentience in plants: (1) the presumed requirement of a centralized brain; (2) centralization of control versus heterarchical organization; and (3) connecting plant research with research on animal nervous systems.

Adaptive Plasticity Of Coloration In Response To Environmental Change, Karissa Coffield

Scholars Week

When rapid environmental changes occur, different selective forces can create phenotypic trade-offs in which a trait can provide fitness benefits or costs under different environmental conditions. Amphibians are particularly vulnerable to environmental change, and previous research has revealed that some species will plastically respond to variation in temperature and ultra-violet radiation (UVR) by altering their coloration. Divergent selection on coloration may change with elevation and climate induced shifts in temperature because high temperatures are likely to result in lighter color morphs but as elevation increases, UVR exposure increases leading to the prediction that darker color morphs will be more common. …

Plants Detect And Adapt, But Do Not Feel, Paul C. Struik

Animal Sentience

Plant sentience is a hot topic in scientific and popular media. There are moral reasons to respect both the service of plants to humanity and their natural integrity as creatures playing their own significant role in a complex ecosystem. However, to infer that plants have certain cognitive capacities that are present also in certain human and nonhuman animals calls for scientific rigor beyond mere analogy. The unique capacities of plants identified by Segundo-Ortin & Calvo are not necessarily linked to sentience. Nor is it likely that sentience is an evolutionary trait that is present to some extent in all living …

Questions About Sentience Are Not Scientific But Cultural, Yoram Gutfreund

Animal Sentience

Abstract: The findings of complex cognitive-like behaviours in plants are surprising and exciting. However, they do not provide a scientific reason for ascribing sentience to plants. The target article, in trying to provide evidence for sentience in plants, exposes the weakness of the science of animal consciousness in general. In this commentary, I try to explain why the scientific method is incapable of resolving the question of which organisms or systems are sentient.

Adaptive Plasticity Of Coloration In Response To Environmental Change, Karissa Coffield

Scholars Week

When rapid environmental changes occur, different selective forces can create phenotypic trade-offs in which a trait can provide fitness benefits or costs under different environmental conditions. Amphibians are particularly vulnerable to environmental change, and previous research has revealed that some species will plastically respond to variation in temperature and ultra-violet radiation (UVR) by altering their coloration. Divergent selection on coloration may change with elevation and climate induced shifts in temperature because high temperatures are likely to result in lighter color morphs but as elevation increases, UVR exposure increases leading to the prediction that darker color morphs will be more common. …