Universal Biochemistry Within and Across Biological Domains and Levels of Organization on Earth

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Description
Universal biology is an important astrobiological concept, specifically for the search for life beyond Earth. Over 1.2 million species have been identified on Earth, yet all life partakes in certain processes, such as homeostasis and replication. Furthermore, several aspects of

Universal biology is an important astrobiological concept, specifically for the search for life beyond Earth. Over 1.2 million species have been identified on Earth, yet all life partakes in certain processes, such as homeostasis and replication. Furthermore, several aspects of biochemistry on Earth are thought to be universal, such as the use of organic macromolecules like proteins and nucleic acids. The presence of many biochemical features in empirical data, however, has never been thoroughly investigated. Moreover, the ability to generalize universal features of Earth biology to other worlds suffers from the epistemic problem of induction. Systems biology approaches offer means to quantify abstract patterns in living systems which can more readily be extended beyond Earth’s familiar planetary context. In particular, scaling laws, which characterize how a system responds to changes in size, have met with prior success in investigating universal biology.

This thesis rigorously tests the hypothesis that biochemistry is universal across life on Earth. The study collects enzyme data for annotated archaeal, bacterial, and eukaryotic genomes, in addition to metagenomes. This approach allows one to quantitatively define a biochemical system and sample across known biochemical diversity, while simultaneously exploring enzyme class scaling at both the level of both individual organisms and ecosystems. Using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Joint Genome Institute’s Integrated Microbial Genomes and Microbiomes (JGI IMG/M) database, this thesis performs the largest comparative analysis of microbial enzyme content and biochemistry to date. In doing so, this thesis quantitatively explores the distribution of enzyme classes on Earth and adds constraints to notions of universal biochemistry on Earth.
Date Created
2020
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Institutional Complexity and Efficiency: How Universities Scale

Description
As the US and the rest of the world face a growing need for affordable and accessible higher education, we must more deeply examine the scalability of our universities: how do they change with size? How do different institutional types

As the US and the rest of the world face a growing need for affordable and accessible higher education, we must more deeply examine the scalability of our universities: how do they change with size? How do different institutional types vary? What makes ASU number one in innovation? At least two of these questions have immediate relevance to not only higher education, but political economy and sustainability as well. We apply to institutions the exciting complex systems framework of scaling, which has led to deep theoretical insight into the structure of biological systems and cities (West, Brown and Enquist 1997, Bettencourt 2013). First we group universities into seven distinct sectors, from public research universities to professional schools. Then we examine the returns to scale of university revenues, expenditures, and graduation rates, by correlating these key variables versus total enrollment. We discover that the sectors exhibit some important similarities, but overall leverage different economies of scale to serve their own priorities. These results imply shared mechanisms and constraints among the entire class of institutions. Furthermore, the uniqueness of each sector reveals their "speciation" into diverse institutional models, offering a fresh (though limited) first look at their scale-dependent complementary roles and competitive advantages. Accordingly, we outline what additional data and analyses might sufficiently strengthen these results to make recommendations, at levels ranging from student and family decisions to individual university strategies to sector-wide and system-wide policies. Promising future directions include longitudinal analysis of university growth patterns, detailed outlier analysis, and deeper theoretical investigation of mechanisms that drive the observed scaling.
Date Created
2017-12
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