Michael Lynch (geneticist)

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Michael Lynch
Born (1951-12-06) 6 December 1951 (age 66)
Auburn, New York, USA
Citizenship USA
Alma mater University of Minnesota
Known for contributions to Population Genetics, Quantitative Genetics,
Awards elected member of National Academy of Sciences, USA, 2009
Scientific career
Fields Genetics, Population genetics, Evolution
Institutions Indiana University, Arizona State University
Doctoral students Sarah Schaack

Michael Lynch (born 1951) is the Director of the Biodesign Institute for Mechanisms of Evolution at Arizona State University, Tempe, Arizona. He held a Distinguished Professorship of Evolution, Population Genetics and Genomics at Indiana University, Bloomington, Indiana. Besides over 250[1] papers, especially in population genetics, he has written a two volume textbook with Bruce Walsh, widely considered the "Bible" of quantitative genetics. Alongside this textbook he has also published two other books. He has been a major force in promoting neutral theories to explain genomic architecture based on the effects of population sizes in different lineages; he presented this point of view comprehensively in his 2007 book "The Origins of Genome Architecture". In 2009, he was elected to the National Academy of Sciences (Evolutionary Biology). Lynch was a Biology undergraduate at St. Bonaventure University and received a B.S. in Biology in1973. He obtained his PhD from the University of Minnesota (Ecology and Behavioral Biology) in 1977.

Research[edit]

Evolution of genome architecture[edit]

Population genetics principles, phylogenetic analyses, rate calculations, and allele frequency spectra of derived SNPs are employed to understand evolutionary mechanisms behind eukaryotic genome complexity.[2] Hypotheses around the ideas that eukaryotic genome complexity evolved as a result of a passive response to reduced population size, deleterious newly arisen introns in species of Daphnia,[3] genomic response to alterations in population size and mutation rates in E. coli[4] and the evolutionary fates of duplicate genes in of species of Paramecium using complete genomic sequencing are investigated.[5] Lynch is working on designing methods that allow for ascertaining the population-genetic features using high-throughput genome sequence data and take into account uncertainties due to low coverage and error-prone sequences.

Role of mutation in evolution[edit]

Most mutations are mildly deleterious[6] and can eventually lead to decreased evolutionary fitness in a species. Using the Tree of Life, Lynch investigates the significant variation across diverse invertebrates and simple eukaryotic and prokaryotic organisms using a mutation-accumulation strategy.[7] To address this mutation diversity and the load of mutation on survival in some species, a novel method involving a mutation accumulation strategy that is followed by whole genome sequencing allows for estimation of error rates in transcription and variation among eukaryotic lineages.[8] The work done to estimate this variation translates to population genetic theories for mutation rates and how somatic mutations can eventually evolve to multicellularity. These approaches promote the evolutionary ideas of the drift-barrier hypothesis.[9]

Role of recombination in evolution[edit]

A major drawback of sexual recombination is the separation of complexes of alleles that have adapted together. Study of Daphnia pulex, a microcrustacean that has the ability to reproduce sexually and asexually based upon which is advantageous at particular evolutionary time points, allows for direct quantification and comparison of recombination rates in mobile genetic elements in sexual and asexual lineages.[10] This species of Daphnia's asexual lineage is rather young in an evolutionary time perspective and rapidly go extinct.[11] It is hypothesized that this rapid extinction is caused by a loss of heterozygosity caused by asexual reproduction as well as gene conversion exposing them to pre-existing deleterious mutations.[6] A new reference genome assembly of this species has recently been generated[12] and attention to the role of recombination in Daphnia has been of hallmark importance to Lynch's research in recent years.

Evolutionary cell biology[edit]

Currently, no formal field of evolutionary cell biology exists. The link between the evolution of phenotypes and molecular evolution is found at the level of cellular architecture. Recent work spearheaded by Michael Lynch and his lab seeks to link traditional evolutionary theory with molecular and cellular biology alongside comparative cellular biology observations. Using Paramecium as a model species, studies of the evolutionary basis of: evolution of cellular surveillance mechanisms, barriers as a result of random genetic drift on molecular perfection, multimeric proteins, vesicle transport and gene expression.[13][14] A majority of this area of Lynch's research is preliminary and the value of this research is yet to be determined, as of 2017, but if fruitful will work to develop a framework for a formal evolutionary cell biology field.

References[edit]

  1. ^ "Publications | The Biodesign Institute | ASU". biodesign.asu.edu. Retrieved 2017-11-08. 
  2. ^ Li, Wenli; Tucker, Abraham E.; Sung, Way; Thomas, W. Kelley; Lynch, Michael (2009-11-27). "Extensive, Recent Intron Gains in Daphnia Populations". Science. 326 (5957): 1260–1262. doi:10.1126/science.1179302. ISSN 0036-8075. PMC 3878872Freely accessible. PMID 19965475. 
  3. ^ Li, Wenli; Kuzoff, Robert; Wong, Chen Khuan; Tucker, Abraham; Lynch, Michael (2014-09-01). "Characterization of Newly Gained Introns in Daphnia Populations". Genome Biology and Evolution. 6 (9): 2218–2234. doi:10.1093/gbe/evu174. 
  4. ^ Lynch, Michael (2010). "Evolution of the mutation rate". Trends in Genetics. 26 (8): 345–352. doi:10.1016/j.tig.2010.05.003. PMC 2910838Freely accessible. 
  5. ^ Lynch, Michael (2006-09-11). "Streamlining and Simplification of Microbial Genome Architecture". Annual Review of Microbiology. 60 (1): 327–349. doi:10.1146/annurev.micro.60.080805.142300. ISSN 0066-4227. 
  6. ^ a b Loewe, Laurence; Hill, William G. (2010-04-27). "The population genetics of mutations: good, bad and indifferent". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1544): 1153–1167. doi:10.1098/rstb.2009.0317. ISSN 0962-8436. PMC 2871823Freely accessible. PMID 20308090. 
  7. ^ Lynch, Michael; Conery, John; Burger, Reinhard (1995-10-01). "Mutation Accumulation and the Extinction of Small Populations". The American Naturalist. 146 (4): 489–518. doi:10.1086/285812. ISSN 0003-0147. 
  8. ^ Lynch, Michael; Gabriel, Wilfried (1990-11-01). "Mutation Load and the Survival of Small Populations". Evolution. 44 (7): 1725–1737. doi:10.1111/j.1558-5646.1990.tb05244.x. ISSN 1558-5646. 
  9. ^ Lynch, Michael; Ackerman, Matthew S.; Gout, Jean-Francois; Long, Hongan; Sung, Way; Thomas, W. Kelley; Foster, Patricia L. (2016-10-14). "Genetic drift, selection and the evolution of the mutation rate". Nature Reviews Genetics. 17 (11): 704–714. doi:10.1038/nrg.2016.104. ISSN 1471-0064. 
  10. ^ Jiang, Xiaoqian; Tang, Haixu; Ye, Zhiqiang; Lynch, Michael (2017-02-01). "Insertion Polymorphisms of Mobile Genetic Elements in Sexual and Asexual Populations of Daphnia pulex". Genome Biology and Evolution. 9 (2): 362–374. doi:10.1093/gbe/evw302. 
  11. ^ Omilian, Angela R.; Cristescu, Melania E. A.; Dudycha, Jeffry L.; Lynch, Michael (2006-12-05). "Ameiotic recombination in asexual lineages of Daphnia". Proceedings of the National Academy of Sciences. 103 (49): 18638–18643. doi:10.1073/pnas.0606435103. ISSN 0027-8424. PMC 1693715Freely accessible. PMID 17121990. 
  12. ^ Ye, Zhiqiang; Xu, Sen; Spitze, Ken; Asselman, Jana; Jiang, Xiaoqian; Ackerman, Matthew S.; Lopez, Jacqueline; Harker, Brent; Raborn, R. Taylor (2017-05-01). "A New Reference Genome Assembly for the Microcrustacean Daphnia pulex". G3: Genes, Genomes, Genetics. 7 (5): 1405–1416. doi:10.1534/g3.116.038638. ISSN 2160-1836. PMC 5427498Freely accessible. PMID 28235826. 
  13. ^ McGrath, Casey L.; Gout, Jean-Francois; Doak, Thomas G.; Yanagi, Akira; Lynch, Michael (2014-08-01). "Insights into Three Whole-Genome Duplications Gleaned from the Paramecium caudatum Genome Sequence". Genetics. 197 (4): 1417–1428. doi:10.1534/genetics.114.163287. ISSN 0016-6731. PMC 4125410Freely accessible. PMID 24840360. 
  14. ^ Catania, Francesco; Wurmser, François; Potekhin, Alexey A.; Przyboś, Ewa; Lynch, Michael (2009-02-01). "Genetic Diversity in the Paramecium aurelia Species Complex". Molecular Biology and Evolution. 26 (2): 421–431. doi:10.1093/molbev/msn266. ISSN 0737-4038. PMC 3888249Freely accessible.