Maike Morrison

Maike Morrison

PhD Student, Stanford University

Hello!

I am a PhD student in Ecology and Evolutionary Biology at Stanford University working with Noah Rosenberg with funding from a Stanford Graduate Fellowship and the National Science Foundation Graduate Research Fellowship Program.

I build mathematical tools to answer biological questions, currently with a focus on population genetics, biodiversity, microbiomes, and cancer.

In May 2020, I graduated from the University of Texas at Austin with a BS in Mathematics through the Dean’s Scholars Honors Program. My undergraduate research was advised by Mark Kirkpatrick and Lauren Ancel Meyers in the UT Austin Department of Integrative Biology. I also conducted summer research with John Witte in the University of California, San Francisco Department of Biostatistics and Epidemiology, and Ephraim Hanks in the Penn State University Statistics Department.

Projects

 
 
 
 
 

How do carcinogen exposure and cancer incidence shape mutational signature diversity in cancer tumors?

February 2023 – Present International Agency for Research on Cancer

I spent much of 2023 as a visiting scientist with Dr. Nicolas Alcala in the Rare Cancer Genomics Group at IARC. During my visit, we developed signature variability analysis, a framework to quantify the diversity of mutational signatures within tumors and the heterogeneity of signatures across tumors in a population. We found that carcinogen exposure increases the diversity of mutational signatures present in a tumor—even in cases when carcinogens were thought not to have genomic effects!

This work is now available as a preprint on medRxiv!

 
 
 
 
 

How can we quantify compositional variability across many microbiome samples?

September 2022 – Present Stanford University Department of Biology

With Drs. Noah Rosenberg and Katherine Xue, I developed FAVA, an Fst-based Assessment of Variability across vectors of relative Abundances. We used FAVA to quantify the temporal stability of microbiomes following an antibiotic perturbation and the heterogeneity of microbiomes across ruminant host species at different regions of the gastrointestinal tract.

Check out our R package on GitHub and preprint on bioRxiv!

 
 
 
 
 

How is Shannon diversity constrained by the abundance of the ith most abundant taxon in a community?

July 2021 – October 2023 Stanford University Department of Biology

Dr. Noah Rosenberg and I derived the upper and lower bounds on the popular biodiversity statistic Shannon entropy when the abundance of the ith most abundant community member is fixed. This project extends previous work which established these bounds conditional on only the first most abundant taxon.

Check out our paper in Journal of Mathematical Biology!

 
 
 
 
 

How can we quantify ancestry variability using the output of population structure inference software?

September 2020 – May 2022 Stanford University Department of Biology

With Drs. Noah Rosenberg and Nicolas Alcala, I developed an $F_{ST}$-based tool, called FSTruct, for quantifying the variability of a population’s estimated ancestry.

Check out our R package on GitHub and paper in Molecular Ecology Resources!

 
 
 
 
 

How many isolation beds are needed to protect people experiencing homelessness in Austin from COVID-19?

April 2020 – May 2021 UT Austin Department of Integrative Biology

Dr. Lauren Ancel Meyers, Dr. Spencer Fox, Tanvi Ingle, and I modeled demand for COVID-19 isolation beds for the Austin homeless population based on epidemic projections. This work was done in collaboration with public health leaders from the City of Austin.

This project is now published in PLOS One! See this link for the open-access paper.

 
 
 
 
 

Mathematical Statistics in Epidemiology: A Discussion of the Mathematical Concepts Employed in Regression Analyses and Studies of Disease Spread.

August 2019 – May 2020 UT Austin Mathematics Department

I wrote an honors mathematics thesis with the supervision of Dr. Stephen Walker as part of my degree through the Dean’s Scholars Honors Program.

You can view an abridged copy of my thesis here!

 
 
 
 
 

What is the genetic basis of how strongly our immune system responds to infectious diseases?

May 2019 – July 2019 University of California, San Francisco Department of Biostatistics & Epidemiology

As part of the UCSF Summer Research Training Program and the Amgen Scholars Program, I worked with Dr. John Witte, Dr. Linda Kachuri, and Dr. Sara Rashkin to conduct genome-wide association studies of immune response strength to 22 distinct antigens.

We identified many interesting and novel single-nucleotide polymorphisms that are implicated in immune response variability.

This work is now published in Genome Medicine! You can find the open-access paper here and my poster here!

 
 
 
 
 

How does terrain patchiness influence spatial infectious disease spread?

June 2018 – August 2018 Penn State University Department of Statistics

As part of The Mathematical Biosciences Institute NSF REU Program, I worked with Dr. Ephraim Hanks and Emily Strong to explore the dynamics of disease spread over patchy terrain through an extensive simulation study.

We found that terrain heterogeneity (i.e. resource selection) can cause population dispersal to be heavy tailed, creating accelerating epidemic waves.

You can view our poster here and a recording of our final presentation here!

 
 
 
 
 

How many ecotypes make up the world’s most abundant photosynthetic organism?

December 2017 – August 2020 UT Austin Department of Integrative Biology

Under Dr. Mark Kirkpatrick, I evaluated the performance of Bayesian Phylogenetics and Phylogeography (an MCMC program for analyzing DNA alignments under the multispecies coalescent model) when applied to prokaryotic genomic data.

I have used this tool to identify independently evolving lineages, or ecotypes, within a superabundant marine cyanobacteria responsible for 5% of global oxygen production, Prochlorococcus marinus.

You can access my poster from the 2019 Evolution Meeting here and our preprint on bioRxiv here!

 
 
 
 
 

What are the drivers of rising vaccination exemptions in Texas schools?

August 2017 – March 2020 UT Austin Department of Integrative Biology

With the guidance Dr. Lauren Ancel Meyers and Dr. Lauren Castro, I analyzed the Texas counties and school districts most at risk of an outbreak due to high conscientious vaccination exemption rates and fit an array of models to identify sociodemographic predictors of these exemptions.

This work is now published in PLOS Medicine! You can find the open-access paper here.

Resources

Graduate School Application Guide

Intending to help younger students in the Dean’s Scholars Honors Program who were hoping to apply to graduate school after finishing their undergraduate degrees, my friend Griffin Glenn and I wrote a guide to graduate school applications! It contains:

  • A timeline beginning in the first year of undergrad
  • An overview of the application and interview/visit process
  • A summary of the application materials

We aimed to share what we wish we knew before we began the application process; we hope it serves you well!

Faith & Science Resources

I spent much of my undergraduate career unaware of organizations seeking both to harmonize faith and science and to provide community for scientists who are also people of faith. Here are a couple of the organizations and resources I wish I had learned of earlier:

  • BioLogos: Founded by Dr. Francis Collins, the former leader of the Human Genome Project and director of the National Institutes of Health, BioLogos invites the church and the world to see the harmony between science and Christian faith by presenting an evolutionary understanding of God’s creation. I also appreciated Dr. Collins’ book The Language of God and the BioLogos podcast by the same name.
  • The AAAS Dialogue on Science, Ethics, and Religion (DoSER): Organized by the American Association for the Advancement of Science, DoSER seeks to facilitate conversation between scientific and religious communities.