reconsidering the definition of life kunio kawamura
TRANSCRIPT
RECONSIDERING THE DEFINITION OF LIFE Kunio Kawamura
Department of Human Environmental Studies, Hiroshima Shudo University 1-1-1, Ozuka-higashi, Asaminami-ku, Hiroshima 731-3195, Japan
[email protected] (Received 26 Aug, 2014, Accepted 21 January, 2015)
Abstract According to my previous works, the definition of life is reconsidered. A point of my view regarding the definition of life is based on taking into account the relationship between a life-like system and the environments. The analysis of life-like systems regarding the metabolism, replication and mutation of information, assignment method between information and function, individuality, and subjectivity towards the environments clearly demonstrated the analogies among life-like systems at different hierarchical levels. Based on these analysis, civilization is regarded as a similar type of biosystem to cell-type organisms. The analysis of characteristics and emergence of civilization as comparing to cell-type organisms would imply both the emergence of life and the definition of life. (Keywords) metabolism, replication, translation, element of life, essence of life
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ïŒïŒçåœãç¹åŸŽä»ããæ§è³ªãããã«ä»ãå ããŠçš®ã ã®çåœã·ã¹ãã ãæ¯èŒãã æåã«ç€ºãã 3ã€ã®èŠä»¶ã«ïŒæ å ±ãšæ©èœã®å¯Ÿå¿ä»ãïŒã·ã¹ãã ãšããŠã®äžäœæ§ïŒç°å¢ã«å¯Ÿããçç©åŽããã®åãããïŒäž»äœæ§ïŒã® 3ã€ã®èŠä»¶ãå ããŠïŒ6ã€ã®èŠä»¶ã«ã€ããŠçç©çã®æ§ã ãªã·ã¹ãã ãæ¯èŒããïŒæ å ±ãšæ©èœã®å¯Ÿå¿ä»ãã¯ïŒçŽ°èåçç©ã«ããã DNAã«ä¿æãããæ å ±ãã¿ã³ãã¯è³ªã RNAãªã©ã®è¡šçŸåååã®æ§é ã»æ©èœãšå¯Ÿå¿ã¥ããããŠãããšããïŒéºäŒååååãšè¡šçŸåååã®å¯Ÿå¿ã¥ãã®æŠå¿µãæ¡åŒµãããã®ã§ãã[1]ïŒäŸãã°ïŒRNAã¯ãŒã«ãã§ã¯ RNAã¯éºäŒååãšè¡šçŸåã®äž¡æ¹ã®åœ¹å²ãæ ã[1,5]ïŒããªãã¡ïŒéºäŒååãšè¡šçŸåãåäžååã§ããããšã«ãã£ãŠå¯Ÿå¿ä»ããããŠããïŒæãååçãªå¯Ÿå¿ä»ãã®ä»çµã¿ã§ãããïŒãã®èãæ¹ã现èã®éå±€ãè¶ ããŠææãŸã§ã®åºãç¯å²ã®çåœã·ã¹ãã ã«æ¡åŒµããïŒãŸãäžäœæ§ãšã¯ïŒçŽ°èåçç©ã§ã¯ç°å¢ã®å€åã«å¯Ÿå¿ããå®å®æ§ãäžã€ã®ã·ã¹ãã ãšããŠç¶ç¶æ§ããã
ããšãªã©ïŒå®å®æ§ãšäžäœæ§ãæã€ããšã§ãã2,3,14ïŒãããã Table 1ã«ç€ºãïŒæ¢åã®å ±åã§ã¯ 2ã4 ã®èŠä»¶ãç¬ç«ã«æ±ã£ãŠãããïŒæ¬è«æã®åŸåã§è¿°ã¹ãããã«ïŒãããã¯æ å ±äžæ¢ç³»ãšã㊠1ã€ã®ã»ãããšããŠãŸãšããïŒTable 1ïŒïŒ ãããã®ç 究ã«ãããŠã¯ïŒçåœçã·ã¹ãã ãšããŠïŒåæ žçç©ïŒçæ žçç©ïŒå€çŽ°èçç©ïŒç€ŸäŒæ§æè«ïŒçš®ïŒçæ ç³»ïŒææãåãäžãäžè¿°ã® 6èŠä»¶ã«ã€ããŠæ¯èŒãã[3]ïŒãŸããã®åæãšããŠïŒããããã®ã·ã¹ãã ã®å¢çïŒæ§æèŠçŽ ïŒæ§æèŠçŽ éã®çžäºäœçšã®çš®é¡ãæ¯èŒããïŒããã«ç€ºããèŠä»¶ã«ã€ããŠãããã®çåœã·ã¹ãã ã®éã«ã¯çžäŒŒãèŠãã ãããšãã§ããïŒäŸãã°ïŒå€çŽ°èçç©ã«ãããŠã¯ïŒæ§ã¯è€è£œïŒå¢å¹ ïŒãšå€ç°ã®ããã®åºæã®ä»çµã¿ã§ããïŒäžèŠãããšçæ žçç©ã®éºäŒååååãšè¡šçŸåååã察å¿ã¥ããä»çµã¿ã¯åãã«èŠãããïŒçæ žçç©ã«ãããŠã¯éºäŒååååã¯çŽ°èæ ž
å ã«æè²äœäžã«ååšããã®ã§ïŒããããæ å ±ãåãåºããªããã°ãªããªãïŒãã®ç¹ããïŒåæ žçç©ãšã¯ç°ãªãåºæã®ä»çµã¿ãçæ žçç©ã¯åããŠãããšèŠãªãããšãã§ããïŒããã«ïŒçæ žçç©ã¯ãªã«ã¬ãã©ã§æ§æããããã€ãã¯ç¬èªã®éºäŒåãæã€ã®ã§ïŒçæ žçç©ãåæ žçç©ã®å ±çäœãšããŠèŠãªãããšãå¯èœã§ãã11ïŒãã®ç¹ãããïŒçæ žçç©ã¯åæ žçç©ãããé«ãéå±€ã®çåœã·ã¹ãã ã§ããïŒãã®éå±€ã§ã®åºæã®æ å ±ã®è€è£œïŒå€ç°ïŒå¯Ÿå¿ä»ãã®ä»çµã¿ãæã£ãŠãããšèŠãªãããšãã§ããïŒãããã®æ¯èŒåæããïŒçåœã·ã¹ãã ã¯éåžžã«å€æ§ã§ãããïŒçžäŒŒçã§ãããããšãæ確ã«ãªã£ãïŒäŸãã°ïŒåæ žçç©ïŒçæ žçç©ïŒå现èïŒïŒå€çŽ°èçç©ã¯ãã䌌ãŠããäžæ¹ã§ïŒçæ ç³»ïŒçš®ïŒç€ŸäŒæ§æè«ïŒææç³»ã¯ïŒããããã«äŒŒãŠããç¹ãšç°ãªãç¹ãå«ãããšãæ確ã«ãªã£ã[3]ïŒ ãŸãïŒäžè¿°ãããšããïŒçåœã·ã¹ãã ãæ§æããèŠçŽ ã¯ç°å¢ãšçŽæ¥çžäºäœçšããªãåŸåãããïŒãããïŒç€ŸäŒæ§æè«ã§ã¯ïŒç€ŸäŒãã®ãã®ãäžã€ã®åäœã®ããã«æ¯ãèããã®ã®åäœãç°å¢ãšçŽæ¥çžäºäœçšããããã«èŠããïŒçç©ã®äžçã¯ãã®èŠ³ç¹ã«ãããŠã極ããŠå€æ§ã§ããïŒç°å¢ã«å¯ŸããŠçåœã·ã¹ãã ãšãã®æ§æèŠçŽ ã®ã©ã¡ããã©ã®ãããç°å¢ãšçžäºäœçšããããšããçšåºŠã¯ïŒãããã®çåœã·ã¹ãã ã®æ§è³ªãç¹åŸŽä»ããææšã§ããïŒ ïŒïŒçŽ°èåçç©ãšä»ã®çåœã·ã¹ãã ã®çžäŒŒ æ¢å ±ã®ç 究ã§ã¯ææç³»ãäž»èŠãªé¡æãšããŠè©äŸ¡ããïŒããã¯ææã·ã¹ãã ãã©ã®ããã«åºçŸããããšããéçšãèŠãããšã§ïŒãçåœã®èµ·æºãïŒãçåœãåºçŸããéçšããæããã«ãããã³ãã«
Table 1. çåœãæç«ããããã®èŠä»¶
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Fig. 2. åæ žçç©ïŒå€çŽ°èçç©ïŒç€ŸäŒæ§æè«ïŒææã®çžäŒŒïŒç°å¢ãšçžäºäœçšããã®ã¯ïŒããããåæ žçç©ã®åäœïŒå€çŽ°èçç©ã®åäœïŒç€ŸäŒæ§æè«ã®ç€ŸäŒïŒææã§ããïŒããããæ§æããèŠçŽ ã§ããïŒçäœååïŒçŽ°èïŒç€ŸäŒæ§æè«ã®åäœïŒããã¯ç°å¢ãšçŽæ¥çžäºäœçšããªãåŸåãããïŒ
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28
ãªãã®ã§ã¯ãªãããšçæ³ããããã§ããïŒ çåœã·ã¹ãã ïŒããªãã¡ïŒçŽ°èåçç©ïŒçæ žçŽ°èïŒå€çŽ°èçç©ïŒææãªã©ã®çåœã·ã¹ãã ã«ã¯ïŒæ å ±ãè€è£œïŒå¢å¹ ïŒããä»çµã¿ïŒæ å ±ãå€ç°ããä»çµã¿ïŒããã³æ å ±ãšæ©èœã®å¯Ÿå¿ä»ãã®åºæã®ä»çµã¿ãååšããïŒä»£è¬ç³»ãšäžäœæ§ãªã©ã«ãããŠãé¡äŒŒç¹ãèŠããããïŒçåœã·ã¹ãã ãšããŠã®ææã·ã¹ãã ã®åæã¯æ¢å ±[3]ã§è©³è¿°ããã®ã§ããã§ã¯ç¹ã«æ å ±ã«é¢ããé¡äŒŒç¹ã®æŠèŠãè¿°ã¹ãã«ãšã©ããïŒçŽ°èåçç©ãšææãšã®çžäŒŒã Fig. 3ã«ç€ºãïŒRNA ã¯ãŒã«ã仮説ã§ã¯ïŒæ å ±ã®è€è£œãšå¯Ÿå¿ä»ãã®ä»çµã¿ã RNAååãæ ãã®ã§ïŒæãåçŽãªæ å ±äŒéç³»ãèªåçã«æ§æãããïŒãŸãçªç¶å€ç°ã¯ç¢ºççãªå€ç°ã§ããïŒæãååçãªå€ç°ã®æ©æ§ã§ãã[1,5]ïŒããé«åºŠã®éå±€ã«ããçåœã·ã¹ãã ã«ãããŠã¯ïŒæ å ±ãè€è£œïŒå¢å¹ ïŒããä»çµã¿ïŒæ å ±ãå€ç°ããä»çµã¿ïŒããã³æ å ±ãšæ©èœã®å¯Ÿå¿ä»ãã®åºæã®ä»çµã¿ãååšããïŒTable 2ïŒïŒäŸãã°ïŒçæ žçç©ã§ã¯åºæ¬çã«ã¯åæ žçç©ãšåãä»çµã¿ã«ãã£ãŠéºäŒååãšè¡šçŸåã察å¿ã¥ããããŠãããšèãããïŒæ žã®äžã«éºäŒååååãããã®ã§ïŒãã®æ å ±ãåãåºããŠæ©èœãšå¯Ÿå¿ã¥ãããšããåºæã®ä»çµã¿ãå¿ èŠã§ããïŒãã®ç¹ã§ã¯ïŒå¯Ÿå¿ä»ãã®ä»çµã¿ãšããŠã¯åæ žçç©ãšçæ žçç©ã¯å€§ããç°ãªããšèããã¹ãã§ããïŒãŸãïŒå€çŽ°èçç©ã§ã¯äœçŽ°èãšçæ®çŽ°èã«ååããŠãããïŒæ§ãšããä»çµã¿ã«ãã£ãŠå¢å¹ ãšå€ç°ãè¡ãåºæã®ä»çµã¿ãå¿ èŠã§ããïŒãã®ç¹ã§ïŒå€çŽ°èçç©ã¯å现èçç©ãšã¯å€§ããç°ãªããšèããã¹ãã§ããïŒããªãã¡ïŒçŽ°èåçç©ã®åºçŸïŒçæ žçŽ°èã®åºçŸïŒå€çŽ°èçç©ã®ç¢ºç«ïŒææã®åºçŸãªã©ã®äžäœã®éå±€ã®çåœã·ã¹ãã ãåºçŸããããã«ã¯ïŒæ å ±è€è£œïŒå€ç°ïŒå¯Ÿå¿ä»ãã«ã€ããŠåºæã®ä»çµã¿ãåºçŸããããšã極ããŠéèŠã§ããããšã瀺åããŠããïŒçåœã®èµ·æºã®ç 究ã«ãããŠïŒæ å ±è€è£œã»å€ç°ãšè¡šçŸåååãšéºäŒååååã®å¯Ÿå¿ä»ããéèŠã§ããããšã«ã€ããŠã¯æ¢ã«å ±éèªèãããïŒãŸãïŒã»ã³ãã©ã«ãã°ãã«èšããããšããïŒæ å ±ã®æµãã¯çåœãç¹åŸŽä»ãã象城ã§ããïŒä»ãå ããŠïŒãããã®çåœã·ã¹ãã ã®çžäŒŒãããïŒæ å ±ã®è€è£œïŒå¢å¹ ïŒïŒå€ç°ïŒæ©èœãšå¯Ÿå¿ã¥ããä»çµã¿ïŒãšããæ å ±äžæ¢ãååšããããšã«å€§ããªå ±éç¹ãããããšãç解ã§ããïŒ ææã¯ãããšããçç©ãšãã®ä»ã®æ§ã ãªèŠçŽ ãå«ãçåœã·ã¹ãã ã§ããïŒææã«ãããŠã¯ïŒå
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