Bacterial Speciation

What is a species? Well, we know a giraffe and an elephant are not the same species. But why not? The answer, according to many scientists, would be that they are not the same species because a giraffe and an elephant cannot produce a baby together. Okay, that makes sense and is a clear definition. Let’s apply it to bacteria.

Instantly, we run into a problem, because bacteria don’t make babies like elephants and giraffes. Instead of two bacteria mating to produce one offspring, one bacterium reaches a point in its life, where it splits itself into two offspring called daughter cells. Because of this, the traditional “biological” concept of species, which is used extensively for animals, does not work. How then, can we determine that one bacterial “species” is different from another bacterial “species?”

This is the question that my research aims to answer, leveraging the power of pangenomics and phylogenetic techniques.

Deep Time Phyolgenies

Peering into the past using molecular data allows us to reconstruct the history of life on earth, from the very last universal common ancestor (LUCA) to all modern life. The TimeTree of Life (timetree.org) provides a database to researchers and the general public who are curious about how different organisms are related to each other and when on the time scale of life on earth, they emerged.

Specifically, I investigate how bacteria (which are the most similar organism to LUCA available to us) how evolved through time, stretching back billions of years ago.