title: Prelife catalysts and replicators.
abstract: Life is based on replication and evolution. But replication cannot be taken for granted. We must ask what there was prior to replication and evolution. How does evolution begin? We have proposed prelife as a generative system that produces information and diversity in the absence of replication. We model prelife as a binary soup of active monomers that form random polymers. 'Prevolutionary' dynamics can have mutation and selection prior to replication. Some sequences might have catalytic activity, thereby enhancing the rates of certain prelife reactions. We study the selection criteria for these prelife catalysts. Their catalytic efficiency must be above certain critical values. We find a maintenance threshold and an initiation threshold. The former is a linear function of sequence length, and the latter is an exponential function of sequence length. Therefore, it is extremely hard to select for prelife catalysts that have long sequences. We compare prelife catalysis with a simple model for replication. Assuming fast template-based elongation reactions, we can show that replicators have selection thresholds that are independent of their sequence length. Our calculation demonstrates the efficiency of replication and provides an explanation of why replication was selected over other forms of prelife catalysis.
authors.affiliation: PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan. ohtsuki.h.aa@m.titech.ac.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ohtsuki
authors.forename: Martin A
authors.initials: MA
authors.lastname: Nowak
mesh_terms: D005075:Biological Evolution; D002384:Catalysis; D019369:Life; D008954:Models, Biological; D000069497:Origin of Life
references.citation: Science. 2002 May 3;296(5569):864-8
references.pmid: 11988562
references.citation: Proc Natl Acad Sci U S A. 2004 May 25;101(21):7965-70
references.pmid: 15148394
references.citation: Science. 2004 Sep 3;305(5689):1474-6
references.pmid: 15353806
references.citation: Sci Am. 2007 Jun;296(6):46-53
references.pmid: 17663224
references.citation: J Mol Evol. 1982;18(5):344-50
references.pmid: 7120429
references.citation: Science. 2001 May 18;292(5520):1319-25
references.pmid: 11358999
references.citation: Biophys J. 2004 Aug;87(2):988-98
references.pmid: 15298905
references.citation: J Mol Biol. 1968 Dec;38(3):381-93
references.pmid: 5718557
references.citation: Science. 1953 May 15;117(3046):528-9
references.pmid: 13056598
references.citation: J Mol Evol. 1982;18(3):196-202
references.pmid: 7097779
references.citation: Orig Life Evol Biosph. 1988;18(3):281-7
references.pmid: 3226720
references.citation: Nature. 2006 May 25;441(7092):502-5
references.pmid: 16724065
references.citation: Proc Natl Acad Sci U S A. 2008 Sep 30;105(39):14924-7
references.pmid: 18791073
references.citation: Proc Natl Acad Sci U S A. 1984 Mar;81(6):1751-3
references.pmid: 6200883
references.citation: Nature. 1994 May 19;369(6477):221-4
references.pmid: 8183342
references.citation: Curr Mod Biol. 1967 Mar;1(1):24-8
references.pmid: 6059307
references.citation: Orig Life Evol Biosph. 1998 Oct;28(4-6):501-14
references.pmid: 11536890
references.citation: Science. 2003 Oct 24;302(5645):618-22
references.pmid: 14576428
references.citation: Proc Natl Acad Sci U S A. 2006 Jul 18;103(29):10952-5
references.pmid: 16829575
references.citation: Curr Opin Chem Biol. 2004 Dec;8(6):629-33
references.pmid: 15556407
references.citation: Science. 2006 Dec 8;314(5805):1558-9
references.pmid: 17158315
references.citation: Nature. 1989 Mar 16;338(6212):217-24
references.pmid: 2466202
references.citation: Nature. 2005 Feb 10;433(7026):581-2
references.pmid: 15703726
references.citation: Chem Biodivers. 2007 Apr;4(4):574-83
references.pmid: 17443872
references.citation: J Mol Biol. 1968 Dec;38(3):367-79
references.pmid: 4887876
references.citation: J Theor Biol. 1989 Apr 20;137(4):375-95
references.pmid: 2626057
references.citation: Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):757-61
references.pmid: 8290596
references.citation: J Theor Biol. 1999 Aug 21;199(4):425-33
references.pmid: 10441460
references.citation: Proc Natl Acad Sci U S A. 2009 May 26;106(21):8601-4
references.pmid: 19433793
references.citation: Orig Life Evol Biosph. 2001 Feb-Apr;31(1-2):103-18
references.pmid: 11296515
references.citation: Nature. 1998 Nov 19;396(6708):245-8
references.pmid: 9834031
references.citation: J Theor Biol. 1986 Nov 21;123(2):127-49
references.pmid: 2442564
references.citation: Proc Natl Acad Sci U S A. 2000 Apr 11;97(8):4112-7
references.pmid: 10760281
references.citation: Nature. 2001 Jan 18;409(6818):387-90
references.pmid: 11201752
references.citation: Nature. 1990 Aug 30;346(6287):818-22
references.pmid: 1697402
references.citation: J Am Chem Soc. 2005 Sep 28;127(38):13213-9
references.pmid: 16173749
references.citation: Gene. 1993 Dec 15;135(1-2):33-6
references.pmid: 8276275
references.citation: Q Rev Biol. 2006 Jun;81(2):105-25
references.pmid: 16776061
references.citation: Trends Ecol Evol. 1992 Apr;7(4):118-21
references.pmid: 21235976
references.citation: Naturwissenschaften. 1977 Nov;64(11):541-65
references.pmid: 593400
references.citation: Nature. 2007 May 24;447(7143):469-72
references.pmid: 17522682
references.citation: Mol Cell. 2005 Feb 18;17(4):471-2
references.pmid: 15721248
references.citation: J Theor Biol. 1987 Oct 21;128(4):463-86
references.pmid: 2451771
references.citation: Orig Life. 1984;14(1-4):565-70
references.pmid: 6462692
references.citation: Nature. 1977 Mar 3;266(5597):78-80
references.pmid: 840303
references.citation: Nature. 2002 Jul 11;418(6894):214-21
references.pmid: 12110897
references.citation: Science. 1993 Sep 10;261(5127):1411-8
references.pmid: 7690155
references.citation: Nature. 1992 Jul 16;358(6383):203-9
references.pmid: 1630488
references.citation: J Theor Biol. 1986 Mar 7;119(1):1-24
references.pmid: 3713221
references.citation: Science. 2004 Jan 9;303(5655):196
references.pmid: 14716004
references.citation: Trends Biochem Sci. 2003 Aug;28(8):411-8
references.pmid: 12932729
references.citation: J Theor Biol. 2009 Feb 21;256(4):586-95
references.pmid: 18996397
references.citation: Chem Biodivers. 2007 Apr;4(4):584-602
references.pmid: 17443873
references.citation: Q Rev Biophys. 1971 Aug;4(2):149-212
references.pmid: 5134461
references.citation: Science. 1998 May 29;280(5368):1451-5
references.pmid: 9603737
references.citation: J Mol Evol. 1982;19(1):47-61
references.pmid: 7161810