Mark Bitter

Check out our paper in Evolution Letters!

We used D. melanogaster pigmentation as a focal trait to explore parallelism in phenotypic and genomic responses to environmental change - read more at the link below 👇

I am seeking a postdoc for my group at UCLA. We work at the intersection of population genetics x microbiome (garud.eeb.ucla.edu). If interested, please message me!

Come join us at UCLA!!! We have a growing population genetics community here and Nandita and her lab are outstanding!

Junior, Assistant, or Associate Specialist – Xue Lab University of California, Irvine is hiring. Apply now!

The Xue lab at UC Irvine is looking for a staff scientist to support our work investigating how microbes interact and evolve in the gut microbiome! Open to a wide range of previous experience levels, see ad for more.
recruit.ap.uci.edu/JPF09601

We are recruiting students who are thinking of applying to Biology PhD programs this fall to apply for the Stanford Biology Preview Program. Please spread the word!

1/n 🧵 Excited to share our new paper! We developed a framework to reveal hidden simplicity in how organisms adapt to different environments, particularly focusing on antibiotic resistance evolution. #EvolutionaryBiology #MachineLearning

Increased rates of hybridization in swordtail fish are associated with water pollution Biodiversity loss can occur when disturbance compromises the reproductive barriers between species, causing them to collapse into a single population through hybridization. Recent research has documen...

1/9 Excited to share the preprint for the second half of my PhD with @mollyschumer.bsky.social: Connecting human environmental impacts to hybridization in swordtail fish through genomics, GIS, water chemistry, and histology. Thread below!

#SciSky

www.biorxiv.org/content/10.1...

Manual validation finds only ultra-long long-read sequencing enables faithful, population-level structural variant calling in Drosophila melanogaster euchromatin The increasing accessibility of long-read sequencing and the rapid development of automated variant callers are promoting the generation of population-level structural variation data. However, the eff...

Excited to share the first manuscript from my PhD in which we leveraged ultra-long Nanopore sequencing, D. melanogaster inbred lines, and a ton of manual validation to investigate the effects of long-read length on population-level structural variant (SV) calling accuracy! doi.org/10.1101/2025...

Mixing microbiomes in vitro reveals rules of community assembly | PNAS Mixing microbiomes in vitro reveals rules of community assembly

Our commentary on the elegant in vitro microbiome coalescence experiments from @goldmandoran.bsky.social @ksxue.bsky.social et al is out.

It was a pleasure to write about one of my favorite microbiome papers of the last few years.

www.pnas.org/doi/10.1073/...

5 relative abundance plots arranged to have increasing compositional variability (variability across relative abundance samples, here vertical bars)

1/ Hey y'all, I'm excited to share my latest paper, which is out now in PNAS! We introduce FAVA, a statistical framework to measure compositional variability across microbiome samples. If you want to measure variability across a stacked bar plot, FAVA is for you! Paper: doi.org/10.1073/pnas...

Thank you for the coverage! Excited that this work, in collaboration with @markcbitter.bsky.social and many others, is now out!

New research shows mosquitoes may be able to adapt to warming temperatures The heat tolerance the research team saw “exceeds that of projected climate warming,” according to the published paper.

A new study led by #EnvironmentalHealth postdoc Lisa Couper finds #mosquitoes may genetically adapt to #ClimateChange more than expected. Her team's findings show increasing risk of #WestNileVirus, #Malaria & other diseases due to the insects' heat tolerance. #GlobalWarming ow.ly/Uzro50V3BRl

Late-stage PhD students:

We want to bring you to NYU Biology to meet peers and make connections with potential postdoctoral mentors. Apply to be part of our Emerging Scholars Symposium!

If you have been affected by the fires in LA, or are concerned about your ability to keep precious Drosophila strains going during the latest funding crisis, we will host your strains as a backup. Please email me.

Please amplify. If you are also able to host fly strains, add your name as well.

Join us at the Gordon Research Seminar (GRS) on Ecological and Evolutionary Genomics in Tuscany, co-chaired by @jcbnunez.bsky.social and me.
If you’d like to present your research and be considered for a talk, make sure to submit your application before April 6th!

Kim Lab at UC Irvine Visit the post for more.

Hello Bluesky friends! I am a #newPI starting at UC Irvine in April, interested in gene regulation and functional genomics in stem cell models of development (esp neural crest). We are hiring at all levels – please reach out/spread the word! sskimlab.org

Dominance reversal maintains large-effect resistance polymorphism in temporally varying environments A central challenge in evolutionary biology is to uncover mechanisms maintaining functional genetic variation1. Theory suggests that dominance reversal, whereby alleles subject to fluctuating selectio...

How is functional variation at large-effect loci maintained in natural populations?

Thrilled to share our work showing how beneficial dominance reversal helps fruit flies maintain a resistance polymorphism as selection varies in their environment! A thread 🧵 1/n

www.biorxiv.org/content/10.1...

Thrilled to see this work, led by @lisacouper.bsky.social now out!
We quantified variation in thermal tolerance in the mosquito, Aedes sierrensis, to quantify how adaptation may alter disease vector distributions under warming. 🧵
www.pnas.org/doi/10.1073/...

In sum, quantifying the adaptive potential of mosquito populations to global warming is critical to accurately forecast changes to disease vector distributions under warming. Stay tuned for exciting extensions of this work!

Finally, we used the parameters quantified from experiment in an evolutionary rescue model and found that our focal population has the potential to track warming as projected under moderate emissions scenarios.

We took a standard GWA approach to identify variants associated with acute heat tolerance (here, thermal knockdown time). The diffuse signal throughout the genome for this trait suggested a potentially much more polygenic basis for prolonged vs acute heat tolerance.

We specifically explored the role of inversions underlying this genomic differentiation, procuring evidence that they widespread in the Ae. sierrensis genome, and twice as abundant in regions with strong signals of thermal selection. (we hope to study these putative inversions much more soon!)

We identified hundreds of SNPs with systematic allele frequency differences between the heat-selected and control replicate populations, signal that was clustered into several distinct regions on each of the three chromosomes.

To quantify the genetic basis of variation in thermal tolerance, we first built a reference genome for Ae. sierrensis, which is now publicly available on NCBI (www.ncbi.nlm.nih.gov/nuccore/JBIN...).

Survival was reduced by 25% in the heat-selection treatment, with survivors of heat selection being roughly 10% smaller, and exhibiting significantly lower adult heat tolerance than those reared in control conditions.

To quantify how much variation in thermal tolerance exists within a natural mosquito pop., we collected Aedes sierrensis wild from a mid-latitude population in Solano County, CA, reared them in common garden for two generations, and split F3 larvae into ‘control’ and ‘heat-selection’ groups.

To circumvent the biosafety risks of working with many mosquito spp., we studied the western tree hole mosquito, Aedes sierrensis – a non-human disease vector. It is widely distributed across a large climate gradient, and easy to collect, rear, and manipulate in lab settings.

How will mosquitoes adapt to climate warming? Mosquitoes may be likely to adapt to climate warming given their short life cycles and strong temperature sensitivity, but key data gaps identified here constrain current estimates of adaptive potenti...

Much warranted effort has aimed to project changes to disease vector distributions under warming, but less it is unknown how simultaneous adaptation to warming conditions may augment or impede distributional changes. (see attached perspective by Lisa and colleagues) elifesciences.org/articles/69630

It was work that wouldn’t have been possible without such a fantastic collaboration of co-authors with a very diverse range of expertise - Erin Mordecai, Tristram Dodge, @jahemker.bsky.social, @bernardkim.bsky.social @mexpositoalonso.bsky.social, and Rachel Brem

Thrilled to see this work, led by @lisacouper.bsky.social now out!
We quantified variation in thermal tolerance in the mosquito, Aedes sierrensis, to quantify how adaptation may alter disease vector distributions under warming. 🧵
www.pnas.org/doi/10.1073/...