Organisms have to deal with many kinds of costs, but dissecting and quantifying each of them, and how they affect adaptation and evolution, is tricky. This is especially true when some costs are "internal" (e.g., due to deleterious mutations) and some are "external" (environmental). In a study led by former postdoc Laasya Samhita (now Assistant... Continue Reading →
Mutations are central for evolution, and recent work has suggested that the type of mutations sampled by organisms may be important for evolution. Earlier work from our lab and that of Lindi Wahl suggested that flipping a long-term mutational bias should be generally beneficial, by allowing populations to sample unexplored mutational space. We have now... Continue Reading →
Many key molecules in our cells are specific enantiomers, and their mirror image forms are not found in living beings. For instance, the sugars in DNA are all left-handed, while amino acids are right-handed. For decades, scientists have wondered whether a completely "flipped" mirror organism would be viable and how it would function. With major... Continue Reading →
A new study led by Tapomoy Bhattacharjee's group shows that rods vs. cocci grow in distinct ways in porous 3D matrices, and these differences make rods more robust to increasing matrix viscosity. Bacteria in natural habitats likely live in such matrices; indeed, the bacteria used in this study were isolated from flour beetle guts in our... Continue Reading →
We are looking to recruit a Postdoctoral Fellow with a start date of February or March 2025. The position is for a minimum of 2 years (extendable for up to 4 years), supported by an ongoing grant from the DBT/Wellcome Trust India Alliance to study the evolutionary effects of mutation bias. Salary and benefits will... Continue Reading →
Bacterial genomes experience lots of mutations that result from a complex mix of DNA damage, errors made by DNA polymerase, and errors repaired or made by repair enzymes. Do these processes leave a tell-tale signature in the genome, and can we use it to infer which processes were most important? A new paper in Genome... Continue Reading →
Several years ago, Arun Prakash and Imroze Khan set up an ambitious experimental evolution study in the lab, infecting populations of flour beetles with the pathogen Bacillus thuringiensis (Bt). They found that different selection regimes led to the evolution of mutually exclusive immune responses – beetles either evolved better basal resistance to Bt, or immune priming... Continue Reading →
Our paper describing the evolutionary effects of shifts in mutation bias is now published! We started out by asking if mutation spectrum could alter the fitness effects of new mutations in E. coli. To our surprise, we found a consistent effect across many environments, but could not attribute the difference to any particular properties of... Continue Reading →
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