Yale Community

Project Description:

Undergraduates are invited to participate in morphological research during the summer of 2026 for work with a curator and graduate student from the Yale Peabody Museum (YPM). This project focuses on applying geometric morphometric methods to primate crania – the student will be working with 3D surface scans of Hylobates lar (Lar Gibbon) crania (N=48). The focus is on characterizing craniodental sexual dimorphism and measuring how this compares to other sexually dimorphic features, including body weight and canine length. Sexual dimorphism in size and shape is an important aspect of mammalian life-histories and is related to social structure, reproduction, and other key features of primates. 

The student will use landmarks, semi-landmarks, anatomical planes, and pseudo-landmarks to generate measures of overall size and shape dimorphism. The results and data produced will aid in assessing the relationship between disparate measures of dimorphism and will be used in later analyses testing hypotheses about the ancestral condition of dimorphism in multiple primate groups. Identifying when and how the evolution of dimorphism has impacted primate morphology allows for analysis of its role in shaping extant primate phenotypes and life-histories. In some primates, males and females are the same size (monomorphic) or females reach larger sizes (female-biased or ‘reverse’ dimorphism). Whether secondary sexual characteristics typical of male-biased dimorphism persist, are absent, or are reversed in monomorphic or ‘reversed’ lineages that descend from a male-biased ancestor is still poorly understood. This project will directly address this question using a taxon where body size sexual dimorphism is much reduced compared to most great apes (e.g., chimpanzees, orangutans, and humans) and Old World monkeys. 

The undergraduate researcher will be involved in key aspects of this project. They will learn to use anatomical characteristics to describe primate features. The researcher will also be involved in all steps of data collection: they will gain experience in producing 3D scans using the Peabody’s Artec Space Spider, learn how to export these scans for use in external software, how to place traditional landmarks, planes, semi- and pseudo-landmarks, as well as how to generate three-dimensional models from CT image stacks. Additionally, the project will involve conducting statistical analyses in R using the data collected during the internship. This project could lead to an expanded senior thesis project, a presentation at a professional conference, and/or a publication in a peer-reviewed journal. The data produced will be directly applicable to ongoing projects of the Mammalian Evolutionary Morphology Lab, and the student researcher will be given the opportunity for continued involvement in research that utilizes these data. 

Timeline: 

Week 1 

• Student researcher will meet with EJS and JHM. The student will be introduced to the lab workspace, receive an access key, and become familiarized with the goals of the project. JHM will demonstrate the study methods and software. 

• The student will join JHM in the Peabody Museum for instruction in using the Artec Space Spider. 

• JHM and the student will scan H. lar crania from the YPM collection, then, after returning to the lab workspace, the student will be instructed in processing scans.  

• Once the student is sufficiently trained in the protocol, they will be working in the same space as JHM and one office over from EJS, making both regularly available for any questions. 

Week 2 

• The student will continue working through the study sample. 

• JHM will instruct the student in the downloading, processing, and subsequent use of CT scan data (as opposed to surface scans). 

• The student will create a project timeline for the remaining weeks. 

Weeks 3-5 

• Continue working through the study sample. 

• Beyond availability for regular questions, the student will have a weekly meeting with JHM discussing the timeline for completion and goals of the project. 

Week 6 

• Data collection should be completed early in the sixth week. 

• The student and JHM will work on analyzing the data, using JHM’s previous analyses of similar morphometric data as a template. 

• The student will draft presentation slides covering Introduction, Methods, Results, and Conclusions for the YPM summer internship symposium. Both JHM and EJS will provide feedback on the slides before the symposium. 

Beyond 

• The student will meet with JHM and EJS to review and practice their presentation before the YPM summer internship symposium. Pending results of the analyses, the student is invited to continue working on this project and their materials in a variety of forms (academic conference submission, senior essay, etc.). 

Advisors:
Professor Eric J. Sargis (Curator of Vertebrate Paleontology and Vertebrate Zoology, Yale Peabody Museum)
Graduate Student Jack H. McBride (Graduate School of Arts and Sciences, Anthropology)

Length: 6 weeks

Stipend: $3,750

Project Description:
With more than 350 species, North American freshwater fish diversity is disproportionately concentrated in the family Leuciscidae, which includes shiners, minnows, chubs, and daces. Despite over 200 years of intense interest in the species diversity of this lineage, numerous species remain undescribed. Among these are at least three species masquerading as the Roseyside Dace, Clinostomus funduloides, a brilliantly colored species found in spring-fed rivers and streams. In this project, the student will (1) use the extensive fish collections of the Yale Peabody Museum to aid in the formal delimitation of these new species from other closely related species of Clinostomus and (2) use genomic data as a guide to examine the mechanisms of speciation in Clinostomus. Research methods will include morphological analysis of museum specimens and collection of DNA sequence data.

Timeline: 
Week 1

• Orientation, training in specimen handling and morphological data collection

Weeks 2-3

• One-week field trip to collect specimens 

Weeks 3-5

• Morphological analysis of museum specimens and newly collected material; DNA extraction and sequencing 

Weeks 6-7

• Data analysis, phylogenetic reconstruction, and synthesis of results 

Week 8

• Preparation of manuscript and presentation of findings 

Advisors:
Professor Thomas J. Near (Curator of Ichthyology, Vertebrate Zoology, Yale Peabody Museum)
 

Mentorship plan:  
The intern will work directly with a graduate student in my lab and me. The intern will meet with me at least twice a week to discuss progress, troubleshoot challenges, and develop necessary research skills. The graduate student will provide day-to-day guidance and training in morphological techniques, molecular laboratory methods, and data analysis. Through these regular interactions, the intern will be trained in specimen handling, morphometric measurements, DNA extraction and sequencing protocols, and phylogenetic analysis. 

Additional Costs:
Travel and accommodation expenses for the one-week field collecting trip, including transportation, lodging, and meals. Molecular laboratory supplies for DNA extraction and sequencing. All of these costs are covered by my research funds. 

Potential outcomes:
We anticipate that this work will result in a manuscript suitable for submission to a peer-reviewed scientific journal. The intern may also present their findings at a lab meeting or departmental seminar. 

Length: 8 weeks

Stipend: $5,000

Project Description:
Planktic foraminifera (heterotrophic protists) are widely used as paleoclimatic proxies. They are one of the major calcifiers in the upper ocean, comprising 20–80% of the marine calcite flux along with coccolithophores. Changes in their populations, size, and species distribution have implications for the global carbon cycle and communities of marine microorganisms. Since the Miocene Epoch (23 – 5.3 million years ago) and into the subsequent Pliocene Epoch, planktic foraminifera (in general, averaged over species) increased their maximum size at low to mid latitudes by almost half, while remaining at the same size at high latitudes. Over that time, the global climate state fundamentally changed with the development of extensive northern hemisphere ice sheets (and thus strongly increased ocean surface temperature gradients in the northern high latitudes), reflected in fundamental global turnover in dominant species of planktic foraminifera. The goal of this project will be to quantify changes in planktic foraminifera size by species over this climatically variable period in Earth history; previous work on foraminifera size over these time periods was limited to using whole assemblage, 95^th percentile sizes to track size change, or using just some species data, leaving unanswered questions about whether specific species were driving the average size trends or whether more abiotic factors were the driver.

The project intern will be measuring individual foraminiferal shells from drilling sites across all oceans in the Pliocene Epoch (3.6 Myr) and during the Last Glacial Maximum (19 kyr) and identifying them by species to find their size distributions, taking advantage of the extensive availability of well-documented samples for these time intervals in the Yale Peabody Museum Invertebrate collections. The YPM intern will learn how to collect morphological data from the YPM IP collections, and how to analyze and interpret the size data of these samples. The intern will image collection slides using the Keyence microscope, measure foraminifera samples using ImageJ, and do statistical analyses on species size distributions with R/R Studio. Additional outcomes include familiarity with data visualization and creating a scientific poster/presentation. There will also be the opportunity to attend a conference at UMass Amherst June 21st – 26th for scientific networking and exposure to other kinds of micropaleontological research. If there is long term interest, inclusion on publications is possible. 

Timeline:  
Week 1–3 (June 1–19)

• Literature review
• Keyence training
• ImageJ training
• R/R Studio training
• Adobe Illustrator introduction
• Data collection and analysis
• Conference preparation (poster making)

Week 4 (Sunday June 21–26)

• FORAMS 2026 conference at UMass Amherst, Amherst MA
• https://sites.google.com/view/forams2026

Week 5 (June 29–July 3)

• Conference debrief
• Continued data collection and analysis

Week 6 - 7 (July 6–17)

• Data collection and analysis

Week 8 (July 20- 24)

• Final presentation to Hull lab group

Advisors:
Dr. Pincelli Hull (Professor of Earth and Planetary Sciences; Associate Curator of Invertebrate Paleontology, Yale Peabody Museum) 
Maoli Vizcaíno (Graduate Student of Earth & Planetary Sciences) 
Eleanor Goetz (Graduate Student of Earth & Planetary Sciences) 

Mentorship Plan:  
The YPM intern will be supervised and trained by graduate students Maoli Vizcaíno and Eleanor Goetz. The intern will be trained in imaging on the Keyence microscope, measuring in ImageJ, and statistical analyses and figure making in R/R Studio and Adobe Illustrator. The intern will be mentored on creating a scientific presentation and attend a conference with the Hull lab, and gain familiarity with working with museum collections. 

Outcomes:

• Attendance to FORAMS 2026 conference at UMass Amherst In June (if the student is interested)
• Familiarity with Keyence imaging (light microscopy and imaging)
• ImageJ experience
• R/R Studio experience, making scientific figures
• Adobe Illustrator experience
• Poster-making experience
• Working in museum setting/with museum collections
• Intro to basic oceanography/paleoceanography concepts and content

Length: 8 weeks

Stipend: $5,000

Project Description:
Small, seasonal wetlands are important amphibian breeding habitat, contribute significantly to methane cycling, and support high insect biodiversity.  They are also vulnerable to changing land use, particularly destruction and contamination by urbanization. However, it is not clear that urbanization always reduces freshwater biodiversity; rather, it may cause shifts in community structure, particularly that of aquatic macroinvertebrates. Within ponds, aquatic macroinvertebrates are excellent indicators of water conditions and are the focal organisms of this project. Aquatic macroinvertebrates include, but are not limited to, larval dragonflies, mayflies, and caddisflies, adult and larval water striders and back swimmers, and snails, worms, and leeches.

We will be continuing monitoring efforts to survey pond macroinvertebrates in Madison (urban), Orange (intermediate), and Eastford (rural) Connecticut to add to existing datasets of amphibians and macroinvertebrates in these ponds. The intern would ideally join in field sampling 2-3 days per week and assist with macroinvertebrate identification using a dissecting microscope and standard dichotomous keys the remainder of each week, following appropriate training. Once processed, we will submit all samples to the Peabody collections. While the broad scope of the project is to look at changing communities across landscapes, the intern will have the option to explore their own questions within this scope.  

Timeline:
Week 1

• Learn field techniques, begin practicing invertebrate identification, preliminary literature review

Weeks 2-7

• Sampling ponds 2-3x per week, processing invertebrate samples on the non-field days

Week 8

• Processing invertebrate samples, preliminary data analysis

Advisors: 
Julia Portmann (PhD Student, Yale School of the Environment)
Dr. David Skelly (Oastler Professor at the School of the Environment and Professor of Ecology and Evolutionary Biology)

Mentorship plan:
Julia Portmann (YSE PhD student) will be the primary mentor and lead the intern in the field and lab. Dr. Dave Skelly will also be available for the student. The student will be given comprehensive training in field safety and sampling techniques as well as microscope techniques and invertebrate identification. The student will also have the opportunity to join Skelly lab meetings and shadow other lab members as interested.

Potential outcomes:
The intern could continue this project as a senior capstone and aim for publication of the research.

Length: 8 weeks

Stipend: $5,000

Project Description:
Sexual size dimorphism (SSD), differences in size or size-related traits between males and females, provides insight into how natural and sexual selection act differently on the sexes through fecundity selection, sexual selection, ecological divergence, and distinct life-history trade-offs. Rattlesnakes (genera Crotalus and Sistrurus) are an exceptional system for studying SSD because they vary widely in habitat, diet, body size, reproductive strategies, and the presence of male-male combat. In this project, students will investigate how male and female morphology has evolved across rattlesnake species and how sexual size dimorphism (SSD) is distributed across the group. Students will work hands-on with preserved rattlesnake specimens at the YPM and other museum collections, collecting linear morphological measurements (e.g., head size, body length, tail length) using digital calipers and discovering patterns directly from natural history material. These measurements will be integrated into a larger morphological database assembled by Dr. Alencar from multiple scientific collections, providing students with a rich comparative context for their analyses. Using the R programming language, students will learn phylogenetic comparative methods to reconstruct and visualize morphological evolution, estimate rates of trait change, and test hypotheses about the drivers of sex-specific evolution. This project offers opportunities for extended research, senior theses, conference presentations, and potential co-authorship on peer-reviewed publications.

Timeline: 
Week 1

• Intro to rattlesnake biology and evolution
• Intro to museum-based research: working with preserved specimens, data collection protocols, and best practices

Week 2-6

• Data Collection and curation 

Week 6 

• Intro to R and comparative methods

Week 7

• Data analysis and interpretation 

Week 8 

• Report drafting 

Advisors:

Dr. Laura Alencar (Associate Research Scientist, Department of Ecology and Evolutionary Biology)
Dr. Martha Muñoz (Assistant Professor of Ecology & Evolutionary Biology; Assistant Curator of Vertebrate Zoology, Yale Peabody Museum of Natural History)

Mentorship plan:
The two interns will receive close, hands-on mentorship from Dr. Laura Alencar throughout the summer internship. Dr. Alencar will work directly with the interns during the initial phase of the project, including joining them during the first week of data collection to provide training and ensure students feel confident working independently with museum specimens. During this period, she will guide students through data collection protocols, help troubleshoot challenges (e.g., uncertainty in specimen sex determination), and establish best practices for consistent data recording. Additionally, Greg Watkins-Colwell, the Yale Peabody Museum’s Collection Manager for Herpetology, will provide an introductory overview of the collections, including guidance on specimen handling, collection use policies, and best practices for working with preserved materials. Greg will remain available in the collections space throughout the data collection period to address questions or concerns as they arise. Dr. Alencar will also be responsible for training interns in data organization, introductory R programming, and statistical analyses necessary for their projects. Students will use their own laptops to digitize data, manage datasets, and perform analyses under guided instruction. While Dr. Alencar will be available for ongoing support as needed, she will also meet with interns every week to discuss project progress, data interpretation, and next steps, as well as to provide broader mentorship on scientific research and communication.

Potential outcomes:
Interns will be encouraged and supported in developing their projects toward publication in a peer-reviewed scientific journal. Where feasible, interns may also have the opportunity to present their work at regional or national scientific meetings (e.g., the Northeast Regional Meeting or the Society for Integrative and Comparative Biology). Conference participation will depend on project progress, abstract acceptance, and the availability of institutional or external travel support.

Length: 8 weeks

Stipend: $5,000