Author Archives: Reid Brennan

About Reid Brennan

I am an evolutionary ecologist and a PhD candidate at UC Davis. I am generally interested in mechanisms allowing populations to evolve and respond to environmental stressors. Specifically, I combine physiological and genomic approaches to understand how fish have evolved to inhabit divergent abiotic environments.

Experimental harvesting reduces gene expression variation

Human activities represent unique selective pressures for natural populations. This is especially true for fish species where we routinely harvest individuals from the wild, i.e., through fishing. It has been recognized for some time that overfishing can result in population … Continue reading

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Posted in adaptation, conservation, evolution, genomics, transcriptomics | Tagged , | 1 Comment

Hybridization and adaptive radiations

As an iconic system in evolutionary biology, I’ve always been interested in African cichlids and the origins of their diversity1. These cichlids represent an adaptive radiation; they’ve evolved rapidly from a single origin to exploit and speciate into open niches … Continue reading

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Conifer convergence

Convergent local adaptation is typically studied within a species or between closely related species. In these cases, it is perhaps not unexpected to observe parallel evolution due to common genetic variation, constraints, etc. Convergence between species is somewhat less studied, … Continue reading

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Posted in adaptation, association genetics, genomics, plants, selection, Uncategorized | Tagged , , | 1 Comment

The trouble with PCR duplicates

The sequencing center just sent your lane of Illumina data. You’re excited. Life is great. You begin to process the data. You align the data. You check for PCR duplicates. 50 percent. Half of your data is garbage. Everything is … Continue reading

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Posted in bioinformatics, genomics, methods, next generation sequencing | Tagged , , , | 5 Comments

New insight into the genetic basis of industrial melanism

The evolution of coloration in peppered moths during the industrial revolution is one of the most well known examples of natural selection in action. Part of the appeal of the system is the apparent simplicity. The once-abundant light colored morph … Continue reading

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Posted in adaptation, association genetics, genomics, mutation, selection | Leave a comment

Steelhead in a random forest: identifying the genetic basis of migration

Genome-wide association studies (GWAS) have been quite successful in identifying variants associated with various phenotypes (I suppose there is some debate surrounding this statement. For an interesting, if dated, discussion look here). While most of this work was originally conducted … Continue reading

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The simpler cichlid: a recent adaptive radiation

If I was asked to name a few of the most compelling systems in evolutionary biology, I’d certainly start with Darwin’s Finches. Next might come peppered moths, African cichlids, stickleback, Caribbean Anolis lizards, or Lenski’s E. coli. What’s interesting about … Continue reading

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Posted in adaptation, evolution, selection, speciation | Leave a comment