Evolutionary Biology

I am a research associate at IISER Pune who is fascinated by the interactions of mutation, drift, and selection in organismal populations. I am particularly captivated by the complexity that underlies the process of adaptation in seemingly simple asexual systems.


In my current research, I use combinations of bacterial experimental evolution, population-wide genomics, and agent-based simulations to study the following:

  • The effects of population size on adaptation and fitness trade-offs

  • The population genetics of divergent character evolution in identical environments

  • Why costs of adaptation, which are a major assumption of theoretical evolutionary models, are rarely detected in experiments.

Peer-reviewed publications

1. Chavhan, Y., Malusare, S. & Dey, S.

Larger bacterial populations evolve heavier fitness trade-offs and undergo greater ecological specialization.

Heredity 124, 726–736 (2020)
Full-text link (Final version on BioRxiv)
Companion article

2. Chavhan, Y., Karve, S. & Dey, S.

Adapting in larger numbers can increase the vulnerability of Escherichia coli populations to environmental changes.

Evolution 73, 836–846 (2019)

Full-text link (Final version on BioRxiv)

​3. Chavhan, Y., Ali, S. I. & Dey, S.

Larger numbers can impede adaptation in asexual populations despite entailing greater genetic variation.

Evolutionary Biology 46, 1–13 (2019)

Full-text link (Final version on BioRxiv)

4. Karve, S., Daniel, S., Chavhan Y., Anand, A., Kharola, S.S.  & Dey, S.

Escherichia coli populations in unpredictably fluctuating environments evolve to face novel stresses through enhanced efflux activity.

Journal of Evolutionary Biology 28, 1131–1143 (2015)

Full-text link

PhD Thesis

The Effects of Population Size on Adaptation and Trade-offs: Insights from Experimental Evolution with Escherichia coli and Individual-based Models

(Defended on September 6, 2019 under the supervision of Prof. Sutirth Dey at IISER Pune)

The May 2020 Heredity Podcast featuring my recent work

00:00 / 17:12

My talk at the Indo-Swiss Meeting on Evolutionary Biology (Dec 2019)

Yashraj Chavhan's talk at the Indo-Swiss meeting on Evolutionary Biology