Michelle Hersh

This course explores infectious diseases—disease caused by bacteria, viruses, fungi, and other parasites—through the lens of ecology. Thinking like a disease ecologist means asking questions about disease at different scales. Rather than considering interactions just between an individual host and a parasite, we will look at disease at the population, community, and ecosystem levels. A disease ecologist may ask questions such as: How does a disease make a jump from one species to another? Why are some environments so conducive to disease transmission? How can we make better predictions of where and when new diseases may emerge and develop better management strategies to combat them? A disease ecologist may even consider infected hosts as ecosystems, where pathogens feed on hosts, compete with one another, and face off with the host’s immune system or its beneficial microbiome. Mathematical models of disease transmission and spread will be introduced. We will consider examples from plant, wildlife, and human disease systems.

Biology, the study of life on Earth, encompasses structures and forms ranging from the very minute to the very large. In order to grasp the complexities of life, we begin this study with the cellular and molecular forms and mechanisms that serve as the foundation for all living organisms. The initial part of the semester will introduce the fundamental molecules critical to the biochemistry of life processes. From there, we branch out to investigate the major ideas, structures, and concepts central to the biology of cells, genetics, and the chromosomal basis of inheritance. Finally, we conclude the semester by examining how those principles relate to the mechanisms of evolution. Throughout the semester, we will discuss the individuals responsible for major discoveries, as well as the experimental techniques and process by which such advances in biological understanding are made. Classes will be supplemented with weekly laboratory work.

Biology, the study of life on Earth, encompasses structures and forms ranging from the very minute to the very large. In order to grasp the complexities of life, we begin this study with the cellular and molecular forms and mechanisms that serve as the foundation for all living organisms. The initial part of the semester will introduce the fundamental molecules critical to the biochemistry of life processes. From there, we branch out to investigate the major ideas, structures, and concepts central to the biology of cells, genetics, and the chromosomal basis of inheritance. Finally, we conclude the semester by examining how those principles relate to the mechanisms of evolution. Throughout the semester, we will discuss the individuals responsible for major discoveries, as well as the experimental techniques and process by which such advances in biological understanding are made. Classes will be supplemented with weekly laboratory work.

How many different species of fungi can live in tiny plant seeds? How many species of bacteria can live in a drop of river water? You may be surprised to learn that that number is actually quite large. The amount of biodiversity in the microbial world is vast but, until recently, peering into this “black box” has been extremely difficult. With the advent of high-throughput DNA sequencing methods, it is now far easier to characterize this cryptic diversity. In this course, students will participate in two ongoing research projects. The first explores the hidden fungal diversity in plant seeds and determines if and how those fungal communities shift in response to landscape fragmentation. The second involves screening bacterial communities in water samples from local rivers for potential human pathogens. Students will learn about current methods to characterize microbial communities, including both high-throughput DNA sequencing and bioinformatics techniques. The course will involve extensive data analyses, including processing of amplicon sequencing data to identify organisms, as well as statistical analyses to explore how the structure of microbial communities changes in response to environmental factors. Students who wish to enroll in this course should have previous laboratory experience in biology and a willingness to learn command-line programming.

Ecology is a scientific discipline that studies interactions between living organisms and their environments, as well as processes governing how species are distributed, how they interact, and how nutrients and energy cycle through ecosystems. Ecologists might ask questions about how plant growth responds to climate change, how squirrel population size or behavior changes in response to acorn availability, or how nutrients like nitrogen and phosphorous cycle in rivers and streams. In this course, students will develop a strong foundational understanding of the science of ecology at the individual, population, community, and ecosystem scales. Throughout the course, emphasis will be placed on how carefully-designed experiments and data analysis can help us find predictable patterns despite the complexity of nature. Students will be expected to design and carry out a field experiment, either individually or in small groups. The course will include a weekly lab section, with most labs held outdoors.

How many different species of fungi can live in tiny plant seeds? You may be surprised to learn that that number is actually quite large. The amount of biodiversity in the microbial world is vast; but, until recently, peering into this “black box” has been extremely difficult. With the advent of high-throughput DNA sequencing methods, it is now far easier to characterize this cryptic diversity. In this course, students will participate in an ongoing research project on the hidden fungal diversity in plant seeds and determine if and how those fungal communities shift in response to landscape fragmentation. Students will learn current methods to characterize microbial communities, including both high-throughput DNA sequencing and bioinformatics techniques. The course will involve both laboratory work and data analyses.

What biological processes led to the development of the incredible diversity of life that we see on Earth today? The process of evolution, or a change in the inherited traits in a population over time, is fundamental to our understanding of biology and the history of life on Earth. This course will introduce students to the field of evolutionary biology. We will interpret evidence from the fossil record, molecular genetics, systematics, and empirical studies to deepen our understanding of evolutionary mechanisms. Topics covered include the genetic basis of evolution, phylogenetics, natural selection, adaptation, speciation, coevolution, and the evolution of behavior and life-history traits.

Ecology is a scientific discipline that studies interactions between living organisms and their environments, as well as processes governing how species are distributed, how they interact, and how nutrients and energy cycle through ecosystems. Although we may think of these processes occurring in “natural” areas with little-to-no human development, all of these processes still take place in environments heavily modified by humans, such as cities. This course will cover fundamental concepts in the discipline of ecology and then further explore how these patterns and processes are altered (sometimes dramatically) in urban environments. We will use examples from our local environment—the New York City metropolitan area—to understand ecological concepts in light of urbanization. The fall semester will include a biweekly outdoor lab session at local parks and field stations. Biweekly individual conferences with students will be held during both the fall and spring semesters. Special attention will be paid to the ecology of local streams and rivers, including field trips and work involving the Sarah Lawrence Center for the Urban River at Beczak. This course will also participate in interdisciplinary activities as part of the Sarah Lawrence Interdisciplinary Collaborative on the Environment (SLICE).

Ecology is a scientific discipline that studies interactions between living organisms and their environments, as well as processes governing how species are distributed, how they interact, and how nutrients and energy cycle through ecosystems. Ecologists might ask questions about how plant growth responds to climate change, how squirrel population size or behavior changes in response to acorn availability, or how nutrients like nitrogen and phosphorous cycle in rivers and streams. In this course, students will develop a strong foundational understanding of the science of ecology at the individual, population, community, and ecosystem scales. Throughout the course, emphasis will be placed on how carefully designed experiments and data analysis can help us find predictable patterns despite the complexity of nature. Students will be expected to design and carry out a field experiment in small groups. The course will include a weekly lab section, with most labs held outdoors at local parks and field stations.

Biology, the study of life on Earth, encompasses structures and forms ranging from the very minute to the very large. In order to grasp the complexities of life, we begin this study with the cellular and molecular forms and mechanisms that serve as the foundation for all living organisms. The initial part of the semester will introduce the fundamental molecules critical to the biochemistry of life processes. From there, we branch out to investigate the major ideas, structures, and concepts central to the biology of cells, genetics, and the chromosomal basis of inheritance. Finally, we conclude the semester by examining how those principles relate to the mechanisms of evolution. Throughout the semester, we will discuss the individuals responsible for major discoveries, as well as the experimental techniques and process by which such advances in biological understanding are made. Classes will be supplemented with weekly laboratory work.

From gut flora of animals to fungi living in tree roots, symbioses are important and widespread throughout the natural world. We can broadly define symbiosis as different species living together in a close association of any nature, from mutualism to parasitism. In this seminar course, we will explore how symbioses are developed, maintained, and broken down and consider the scientific challenges to understanding the function of such associations. We will read and discuss papers from the primary literature exploring a broad range of taxonomic groups, including fungus-farming ants, bioluminescent bacteria living in squid, figs and their wasp pollinators, parasitic butterflies, and sloths and the moths that live in their fur. We will place a special emphasis on mutualisms, or interactions in which both partners benefit—unless, of course, one cheats. We will also think carefully about how to design scientific experiments to understand the nature of symbioses, as well as how to design and carry out class experiments on mutualisms between plants and nitrogen-fixing bacteria.

Western literature and culture deeply influence how our country negatively perceives transitional spaces, such as the spaces between cultivated land and forest or between water and land. The need for control pushes us to reshape or eliminate marshes, swamps, thickets, and other forms of overgrowth. Similarly, we feel uncomfortable considering the soils in which we bury our dead—or we ignore them completely. Yet, a closer examination of the biology of decay reveals cycles of life that follow death, with growth, reproduction, and nutrient exchange accompanying decay at every turn. We will read excerpts of literary works that have shaped our cultural perception of decay and of these transitional states and spaces, including works by Sophocles, Mary Shelley, Alice Walker, Robin Wall Kimmerer, and others. We will also explore the ecosystems themselves through lab experiments and trips to local parks and field stations (Center for the Urban River at Beczak, Untermeyer Gardens). This joint course will evaluate the divide between culture and science and explore how cultural representations may evolve with an adequate framing of scientific research and findings. This course fully participates in the collaborative interludes in the Sarah Lawrence Interdisciplinary Collaborative on the Environment (SLICE) Mellon course cluster.

Humans are bathing in a sea of microbes. Microbes coat our environments, live within our bodies, and perform functions both beneficial and detrimental to human well-being. This course will explore the biology of microorganisms, broadly defined as bacteria, archaea, viruses, single-celled eukaryotes, and fungi. We will study microbes at multiple scales, including the individual cell, the growing population, and populations interacting with one another or their environments. Microbial physiology, genetics, diversity, and ecology will be covered in depth. Particular emphasis will be given to the role of microbes that cause infectious disease in humans and microbes that play critical roles in ecological processes. Seminars will be supplemented by a weekly lab section to learn key microbiological techniques and methods, most notably culturing and identifying bacteria.