Image: Libby
Research group : My research addresses a single fundamental question: how do simple organisms evolve into complex ones?
My research group studies various topics related to the evolution of biological complexity, including the origins of multicellularity, life cycles, syntrophy, and organizational scales. Here I give a brief synopsis of some of the topics we investigate.
Multicellularity and life cycles
A pivotal innovation for life on earth was the evolution of multicellularity. This was not a singular event but rather evolved in dozens of independent lineages. Understanding what led to the evolution of multicellularity is challenging; however, because the origins of multicellularity occurred millions of years ago and are largely absent from the fossil record. Recent experiments make it possible to study this pivotal event in the lab by using microorganisms to evolve primitive multicellularity de novo . Such experimental systems provide excellent opportunities to test hypotheses about the conditions that facilitated the evolution of multicellularity. We collaborate with talented experimentalists like William Ratcliff to marry theory with empirical results and uncover general principles of how life evolves to be multicellular.
Syntrophy and microbial trade
Microbes live in complex communities where goods such as metabolites are produced and exchanged. These communities often exhibit division of labor and can allow a community to live in environments where no single organism could. Since these microbial relationships can persist across generations, they can be viewed as an alternative to a multicellular lifestyle. Understanding the evolution of these trading communities provides a clearer picture of the different routes by which life increases in complexity.
Endosymbiosis and the origins of the mitochondria
A key event during the evolution of life on earth was the endosymbiotic association that gave rise to mitochondria. This singular event offered cells a new source of energy and established the eukaryotic lineage, responsible for all large multicellular organisms. Despite its significance, little is known about the likelihood or significance of acquiring an organelle like the mitochondrion, in general. In collaboration with Chris Kempes and Jordan Okie, we are working to fill in some of these knowledge gaps using eco-evolutionary modeling and allometric scaling. The aim is to uncover general principles that govern the probability, fitness consequences, and physiological tradeoffs of an endosymbiotic association.
Bet hedging and phenotypic plasticity
Many microbes have evolved the capacity to switch between at least two phenotypic states. While some switching is in response to a signal such as environmental change; other switching occurs preemptively without any apparent signals. This second type of switching can be understood in the context of bet hedging. Microbes that produce a phenotype that is initially costly or maladapted may gain a benefit should the environment change unpredictably. In particular, microbes that switch phenotypes can survive challenging, fluctuating environments like those that might occur during an antibiotic regimen. We are interested in the mechanisms and drivers of phenotype switching—especially how seemingly random switching might evolve into a regulated part of an organism’s life cycle.
Abiotic vs biotic in the search for biosignatures
We are members of The Laboratory for Agnostic Biosignatures (LAB) which is developing techniques to detect new forms of life in the universe. Funded by the NASA Astrobiology Program, the LAB team includes biologists, chemists, computer scientists, mathematicians, and instrument engineers. The team’s aim is to identify possible signs of life—and ways of detecting them—that are not constrained by how we understand life on earth. For example, living organisms on Earth produce a complex set of molecular compounds in order to maintain themselves and reproduce. While life elsewhere may not use the exact same compounds or subset of them, we might expect a certain amount of molecular complexity to be a feature and biosignature of life anywhere. Thus, one area of investigation for our team is the chemical complexity generated in biotic and abiotic processes.
The research is financed by the Swedish Research Council, Kempe Foundation, NASA, and the National Science Foundation.
Suvam's project concerns how bacteria respond to external stressors like antibiotics and develop resistance.
South Korean researchers visited IceLab as part of STINT research exchange in modeling ecology and evolution.
'Can microbes distinguish friend from foe?' only DDLS funded PhD project at UMU in recent call.
