Evolution Commons^™

Temperate Eurasian Origins Of Hawaiian Chenopodium (Amaranthaceae) Plus Description Of A New Species Endemic To Moloka‘I, Jason T. Cantley, Angela J. Mcdonnell, J Branson, S R. Long, W Garnett, Christopher T. Martine

Faculty Journal Articles

Chenopodium taxa of Hawai‘i are tetraploids distinguished from other members of the circumglobally distributed genus by minute morphological characters. Because of these reasons, the geographic origin of Hawaiian Chenopodium has remained unclear. Across the Hawaiian Archipelago, Chenopodium taxa are morphologically variable and grow in highly disparate xeric habitats, especially in terms of precipitation, temperature, wind, salt spray, and solar irradiation. Habitats include dry subalpine shrublands, sandy beach strand of atolls in the Northwest Hawaiian Islands, dry forests, and precipitously tall sea cliffs of northwestern Moloka‘i. From the Moloka‘i sea cliffs, which are battered by high energy winds, salt spray, and …

The Origin And Evolution Of Flower Characters In Angiosperms With A Case Study On The Genetic Basis Of Zygomorphic Corolla Development In Bee And Hummingbird Pollinated Species Of Schizanthus (Solanaceae), Ghadeer Bukhari

Theses and Dissertations

This Ph.D. dissertation investigates two main projects separated into two chapters, one for each. The first chapter explores the evolution of flowering plants (angiosperms), a macro-scale study. The second project is on a micro-scale that focus on exploring the genes that regulate the similarities and the differences of flower morphology reflecting their different pollination syndromes in two species of Schizanthus (Solanaceae), i.e., S. pinnatus, a bee-pollinated flower, and S. grahamii, a hummingbird- pollinated flower.

In the first chapter, I used floral diagrams to study the origin and the evolution of floral traits in angiosperms, a new set of morphological data …

Evolutionary Ecology Of The Native Johnny Darter (Etheostoma Nigrum) And The Invasive Round Goby (Neogobius Melanostomus): A Genomic Perspective, Abby Joyce Wicks

Wayne State University Dissertations

Round goby (Neogobius melanostomus) is an invasive fish present in all five Great Lakes and is becoming increasingly common in their tributaries. Johnny darter (Etheostoma nigrum) is a native species that often coexists with round goby. Here, I use traditional population genetic methods and genomic tools to explore the evolutionary ecology of these species. First, historic factors are addressed as a source of variation in study populations by characterizing patterns of mitochondrial DNA variation throughout Lower Michigan. Round goby populations were largely homogenous and exhibited no evidence of overarching historical genetic structure, consistent with the recent invasion and rapid expansion …

Molecular Mechanisms Shaping Host Range Of A Vector-Borne Pathogen, Thomas Macgregor Hart

Legacy Theses & Dissertations (2009 - 2024)

Vector-borne diseases, such as Lyme disease caused by Borrelia burgdorferi sensu lato (Bbsl), have narrow host ranges and are apt models to study host-microparasite coevolution. Some species and strains of Lyme borreliae (LB) are specialists, infecting only mammalian or only avian hosts (ex. Borrelia afzelii and B. garinii, respectively), while others are generalists and infect both hosts (ex. B. burgdorferi). Such host tropisms are hypothesized to be partially shaped by the ability of these pathogens evade host immune defenses, such as complement. Complement is a first line host defense against invading pathogens that kills LB in vitro and inhibits spirochete …

Asian Elephant Rescue, Rehabilitation And Rewilding, Liv Baker, Rebecca Winkler

Animal Sentience

Thailand has fewer than 10,000 elephants left. More of them are living in captivity to serve the tourist industry under grim conditions than are living free in what is left of their wild habitat. Conservation efforts need to be focused on all surviving members of the species, captive and free, but they need to take into account the inextricable entanglement of human and nonhuman animal lives in Thailand today. There is an opportunity for rescuing, rehabilitating and reintroducing captive elephants to the wild with the help of the traditional expertise of a mahout culture that has been elephant-keeping for centuries. …

Rewilding And Domestication: Clarifying Terminology, Catia Correia-Caeiro

Animal Sentience

Baker & Winkler (B&W) describe the state of Asian elephant conservation, raising unique issues, and proposing a direction based on rewilding. The long history and socio-biology of elephants and humans has some parallels with the domestication of dogs (and other species). However, markers of domestication seem absent from elephants. The proper use of terms such as “wild” and “domestic” is crucial in defining the best conservation strategies, and, more important, in attending to the welfare needs of individuals, which can differ between wild and domestic animals. B&W’s target article represents an important starting point for discussion around elephant conservation, but …

Innovation In Meat Production: A Problem And An Opportunity, Christopher J. Bryant

Animal Sentience

Innovation in meat production has enabled modern humans to inflict far greater harm on animals, the environment, and public health than was possible just a few decades ago. Wiebers & Feigin aptly express the urgency with which these issues must be addressed. Those advocating for animals on moral grounds face resistance from omnivores citing taste, price and convenience. Further innovation in meat production (plant-based and cultured meat) will enable us to preserve the experience of eating meat whilst phasing out the many problems caused by industrial animal farming.

Harm, Earth Jurisprudence And Human/Nonhuman Relationships, Tanya Wyatt

Animal Sentience

To prevent the next pandemic and to protect the environment and non-human animals, there needs to be a clear definition of harm and a legal system grounded in Earth Jurisprudence. Drawing on evolutionary principles to redefine harm and to radically alter the legal system to be Earth-centred will help ensure that harmful actions like certain wildlife trade, wildlife trafficking, and intensive farming do not threaten the survival of any life.

Covid-19, Evolution, Brains And Psychology, Frederick Toates

Animal Sentience

Attention needs to be directed to the processes that control behavior in humans and the adaptive problems that they solved in our early evolutionary environment. The evolutionary mismatch between the current environment and the human brain can yield important insights into the problems that beset us in the context of environmental degradation and nonhuman animal welfare.

Re-Engage With The World For Global Health And Animal Welfare, Bradley J. Bergstrom

Animal Sentience

Wiebers & Feigin (2020) make a strong argument for measures that would limit future zoonoses, such as the COVID-19 pandemic, by closing live-animal markets, changing our habits of food consumption and production, and reducing habitat destruction. These would help human health, animal welfare, and conservation of at-risk wildlife all at the same time. China’s command-and-control government can accomplish some of these things by edict, but slower-to-act western democracies play a surprisingly large role in these global problems by the power of their consumerism, including the illicit wildlife trade. We citizens need to insist that our government use all of its …

Thinking Longer, Looking Deeper, Ronnie Z. Hawkins

Animal Sentience

We need to situate the present crisis within the larger context of what we humans have done to the nonhuman forms of life with which we evolved, taking a longer view of our own evolutionary origins and a deeper look at what might be a more appropriate role for our species to play within the Biosphere.

Bridging The Empathy Gap For Invertebrates, John M. Marzluff

Animal Sentience

The actions of sentient vertebrates command our attention and inform our morality. Mikhalevich & Powell (2020) (M&P) argue that similar activities in a wide range of invertebrates with central nervous systems should do likewise. However, humans most readily empathize with creatures we recognize as similar in behavior, physiology, or appearance to ourselves. Helping humanity overcome this bias is a significant challenge for those who study invertebrates. Until this empathy gap is bridged, I believe few people and the policies they craft will afford invertebrates the moral standing that M&P argue they deserve. Therefore, I suggest those interested in raising appreciation …

Affective Sentience And Moral Protection, Russell Powell, Irina Mikhalevich

Animal Sentience

We have structured our response according to five questions arising from the commentaries: (i) What is sentience? (ii) Is sentience a necessary or sufficient condition for moral standing? (iii) What methods should guide comparative cognitive research in general, and specifically in studying invertebrates? (iv) How should we balance scientific uncertainty and moral risk? (v) What practical strategies can help reduce biases and morally dismissive attitudes toward invertebrates?

Sentience In Evolutionary Context, Jon Mallatt, Todd E. Feinberg

Animal Sentience

We appreciate the goals of Mikhalevich & Powell (M&P) and largely agree with their conclusions but we differ on some of their definitions and terms. Affects (emotional feelings) should be part of sentience. Although the evidence presented for insect sentience is strong, we list some of the counterevidence that should be considered. Our own research supports M&P’s choice of arthropods, cephalopods, and vertebrates as the only sentient organisms with moral status.

Relationship Between Cognition And Moral Status Needs Overhaul, Carrie Figdor

Animal Sentience

I commend Mikhalevich & Powell for extending the discussion of cognition and its relation to moral status with their well researched and argued target article on invertebrate cognition. I have two small criticisms: that the scala naturae still retains its appeal to some in biology as well as psychology, and that drawing the line at invertebrates requires a bit more defense given the larger comparative cognitive-scientific context.

Insect Sentience And The Rise Of A New Inclusive Ethics, David Baracchi, Luigi Baciadonna

Animal Sentience

Welfare protections for vertebrates are grounded in the belief that vertebrates are sentient and capable of feeling whereas invertebrates are not. We agree with Mikhalevich & Powell that the exclusion of small-brained invertebrates from bioethics is not warranted by the current state of the scientific evidence. The choice to promote protection for certain invertebrates should be based on the Animal Sentience Precautionary Principle (ASPP). This principle should not prevent us from conducting experimental research with non-human animals to advance knowledge. However, we believe that it is important to outline practical guidelines to manage the wellbeing of invertebrates, while accumulating further …

An Assessment Of Convergence In The Feeding Morphology Of Xiphactinus Audax And Megalops Atlanticus Using Landmark-Based Geometric Morphometrics, Edward Chase Shelburne

Master's Theses or Doctor of Nursing Practice

Convergence is an evolutionary phenomenon wherein distantly related organisms independently develop features or functional adaptations to overcome similar environmental constraints. Historically, convergence among organisms has been speculated or asserted with little rigorous or quantitative investigation. More recent advancements in systematics has allowed for the detection and study of convergence in a phylogenetic context, but this does little to elucidate convergent anatomical features in extinct taxa with poorly understood evolutionary histories. The purpose of this study is to investigate one potentially convergent system—the feeding structure of Xiphactinus audax (Teleostei: Ichthyodectiformes) and Megalops atlanticus (Teleostei: Elopiformes)—using a comparative anatomical approach to assess …

Landscape Ecology And Population Genomics Of Two Sympatric Pitviper Species Across A Fragmented Appalachian Landscape, Thomas Maigret

Theses and Dissertations--Biology

Understanding the link between landscape patterns and ecological and evolutionary processes is an important prerequisite for informed wildlife conservation and management, especially in rapidly changing landscapes. Until recently, the inaccessibility of spatial and genomic data sets of sufficient resolution limited our ability to incorporate the impacts of landscape patterns into predictions of ecological and environmental outcomes. In this dissertation, I utilized several high-resolution spatial and genomic data sets to address ecological questions in a rapidly fragmenting landscape in southeastern Kentucky. Overall, my results indicate that large-scale surface coal mining is causing widespread homogenization of landforms, resulting in a uniquely permanent …

Predicting Patterns Of Gene Family Evolution In Taxa With Similar Ecological Niches, Kim Vertacnik

Theses and Dissertations--Biology

To fully understand the genetic basis of adaptation, we need to know its predictability—the extent to which specific selective pressures and contexts can yield corresponding genetic changes. In particular, the repeated colonization of similar, specialized environments by different taxa is ideal for assessing the frequency of reoccurring changes in the same genes or functions. But compared to a growing body of literature on the convergent evolution of individual genes, far less is known about the repeatability of gene family evolution, where families (defined here as groups of genes that share sequence and functional similarity from common ancestry) can expand (gain …

Limb Development In Salamanders: An Evolutionary Perspective To The Tetrapod Limb, Sruthi Purushothaman

Theses and Dissertations--Biology

Vertebrate limb is an ideal model to study growth, patterning and morphogenesis and the interplay between these processes. The developing limb bud is a three-dimensional structure and its outgrowth depends on the interaction between 2 important signaling centers: the Apical Ectodermal Ridge (AER) at the junction of the dorsal and ventral halves of the limb bud and the Zone of Polarizing activity (ZPA) in the posterior mesenchyme. These centers produce their respective key molecules and the close interplay between them specifies structures along the anterior-posterior (thumb to pinky), proximal-distal (shoulder to fingertips) and dorsal-ventral (knuckle to palm) axes.

Developmental biologists …