Zachary Blount

Zachary D. Blount
Born January 21, 1977
Nationality American
Education

Georgia Institute of Technology (Bachelor of Science, 1999) University of Cincinnati (Master of Science, 2003)

Michigan State University (PhD, 2011)
Employer Michigan State University

Zachary David Blount (born January 21, 1977) is an American evolutionary biologist working as a postdoctoral researcher in the lab of Richard Lenski at Michigan State University.[1][2] He is best known for his work with the evolution of aerobic citrate consumption (Cit+) in an E.coli population in the long term evolution experiment.[3][4][5] His work was recently featured on Through the Wormhole with Morgan Freeman.[6]

Early Life and Education

Zachary D. Blount was born and raised in Georgia where he developed an early interest in science. He earned high honors in Biology at Georgia Institute of Technology, where he was introduced to microbiology by professor emeritus Thomas Tornabene.[7] He obtained his masters from the University of Cincinnati, where he worked on insertion sequence elements of hyperthermoacidophilic Archaea of the genus Sulfolobus under the guidance of Dennis Grogan. He moved to Michigan State University in 2003 for his doctoral work with Richard Lenski.

Research

In 2003, 15 years and 33,000 generations after Richard Lenski had set up the long term evolution experiment,[8][9] one lineage of E.coli began to show very high turbidity.[4][10] Work done by postdoctoral researcher Christina Borland showed that this elevated turbidity was due not to contamination, and confirmed that aerobic growth on citrate had spontaneously evolved in the population.[11] Blount went on to conduct a series of 'evolutionary replay experiments' in which he replayed the evolution of the population in which aerobic citrate usage evolved from different clonal genotypes isolated from different time points to examine how the propensity to mutate to Cit+ changed. This analysis involved examination of several trillion bacterial cells, and showed that clones from later generations had significantly increased rates of mutation to Cit+, indicating that evolution of the trait in the population was contingent upon a history in which "potentiating" mutations accumulated that made it mutationally accessible. Later genomic analysis of clones from the population established the immediate genetic and biochemical basis of the Cit+ trait to be a tandem duplication mutation that placed a silent citrate transporter gene under the control of a new promoter that caused its expression when oxygen is present, an example of promoter capture and gene exaptation.[4][12][13] Based on these findings, Blount proposed a model for the evolution of complex traits: 1. potentiation, in which mutations that make the trait evolutionarily accessible accumulate, 2. actualization, in which a mutation produces a phenotypic switch in which the new trait is manifested, and 3. refinement, in which natural selection accumulates subsequent mutations that make the new trait more effective.[4][14]

Currently, Blount is further investigating how complex traits evolve, how novel traits impact ecology, and how speciation occurs in asexual populations based on models proposed by Fredrick Cohan of Wesleyan University.[15]

References

  1. ↑ Boytchev, Hristio (2012-09-19). "Evolutionary innovation caught in the act". The Washington Post. ISSN 0190-8286. Retrieved 2016-03-13.
  2. ↑ "Similar Data, Different Conclusions | The Scientist Magazine®". The Scientist. Retrieved 2016-03-13.
  3. ↑ Zimmer, Carl (2007-06-26). "Fast-Reproducing Microbes Provide a Window on Natural Selection". The New York Times. ISSN 0362-4331. Retrieved 2016-03-13.
  4. 1 2 3 4 Blount, Zachary D.; Borland, Christina Z.; Lenski, Richard E. (2008-06-10). "Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli". Proceedings of the National Academy of Sciences of the United States of America 105 (23): 7899–7906. doi:10.1073/pnas.0803151105. ISSN 0027-8424. PMC 2430337. PMID 18524956.
  5. ↑ Blount, Zachary D.; Barrick, Jeffrey E.; Davidson, Carla J.; Lenski, Richard E. (2012-09-27). "Genomic Analysis of a Key Innovation in an Experimental E. coli Population". Nature 489 (7417): 513–518. doi:10.1038/nature11514. ISSN 0028-0836. PMC 3461117. PMID 22992527.
  6. ↑ "Evolution is Like Poker". Discovery Science. Retrieved 2016-03-05.
  7. ↑ "About Me". Blount Lab. Retrieved 2016-03-05.
  8. ↑ "Evolving E. coli". Science News. Retrieved 2016-03-13.
  9. ↑ Lenski, Richard E. (2011-01-01). "Evolution in Action: a 50,000-Generation Salute to Charles Darwin". Microbe Magazine 6 (1): 30–33. doi:10.1128/microbe.6.30.1.
  10. ↑ Holmes, Bob. "Bacteria make major evolutionary shift in the lab". New Scientist. Retrieved 2016-03-13.
  11. ↑ "BBC Knowledge - April 2009 - Evolution in Action". www.nxtbook.com. Retrieved 2016-03-05.
  12. ↑ Boytchev, Hristio (2012-09-19). "Evolutionary innovation caught in the act". The Washington Post. ISSN 0190-8286. Retrieved 2016-03-05.
  13. ↑ Holmes, Bob. "Bacteria make major evolutionary shift in the lab". New Scientist. Retrieved 2016-03-05.
  14. ↑ "News - Video - Postdoc researcher Zachary Blount discusses discovering the process of E. coli evolution. | NSF - National Science Foundation". www.nsf.gov. Retrieved 2016-03-05.
  15. ↑ "Bacterial speciation". ncse.com. Retrieved 2016-03-05.
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