Daniel H. Janzen

Daniel Hunt Janzen (an haife shi a ranar 18 ga watan Janairun  shekara ta 1939, a Milwaukee, Wisconsin ) masanin ilimin juyin halitta ne na kasar  Amurka kuma mai kiyayewa. Ya raba lokacinsa tsakanin farfesa a ilmin halitta a Jami'ar Pennsylvania, inda yake Farfesa DiMaura na ilmin halitta, da bincike da aikin gona a Costa Rica. 

Janzen da matarsa Winifred Hallwachs sun tsara bambancin halittu na Costa Rica. Ta hanyar shirin DNA barcoding, Janzen da masanin kwayoyin halitta Paul Hebert sun yi rajistar samfurori sama da 500,000 da ke wakiltar fiye da nau'in 45,000, wanda ya haifar da gano nau'in nau'in da ke kusa da kama da juna waɗanda suka bambanta dangane da kwayoyin halitta da yanayin muhalli. Janzen da Hallwachs sun haɓaka wasu ra'ayoyin da suka fi tasiri a cikin ilimin muhalli waɗanda ke ci gaba da tasiri ga bincike fiye da shekaru 50 daga baya.

Janzen da Hallwachs sun taimaka wajen kafa Yankin Tsaro na Duniya na Guanacaste, daya daga cikin tsofaffi, mafi girma kuma mafi kyawun ayyukan sabunta mazaunin a duniya.

 Rayuwa ta farko da ilimi 
An haifi Daniel Hunt Janzen a ranar 18 ga watan Janairun 1939, a Milwaukee, Wisconsin .  Mahaifinsa, Daniel Hugo Janzen,  ya girma a cikin al'ummar noma ta Mennonite kuma ya yi aiki a matsayin Darakta na Hukumar Kifi da Kayan daji ta Amurka. Mahaifinsa da mahaifiyarsa, Miss Floyd Clark Foster na Greenville, South Carolina, sun yi aure a ranar 29 ga Afrilu, 1937. 

Janzen ya sami B.Sc. digiri a ilmin halitta daga Jami'ar Minnesota a 1961, da Ph.D. daga Jami'an California, Berkeley a 1965. 

 Ayyuka 
A cikin 1963, Janzen ya halarci darasi na watanni biyu a cikin ilmin halitta na wurare masu zafi wanda aka koyar a wurare da yawa a duk faɗin Costa Rica. Wannan Cibiyar Nazarin Kimiyya ta Ci gaba a cikin Ilimin Halitta ta Tropical ita ce ta farko ga darasi na Tushen Halitta a cikin Ilimi na Tropical, wanda Janzen ya tsara don Ƙungiyar Nazarin Tropical (OTS), ƙungiyar jami'o'i da yawa na Arewacin Amurka da Costa Rican. Janzen ya koma a 1965 a matsayin malami kuma ya ba da lacca a akalla ɗaya daga cikin darussan shekara-shekara guda uku a kowace shekara tun daga lokacin.

Janzen ya koyar a Jami'ar Kansas (1965-1968), Jami'ar Chicago (1969-1972), da Jami'ar Michigan (1972-1976) kafin ya shiga bangaren a Jami'an Pennsylvania .  A can shi ne Farfesa DiMaura na Ilimin Kare Muhalli, da bincikensa da aikin gona a Costa Rica.

Janzen ya kuma rike mukamai na koyarwa a Venezuela (Universidad de Oriente, Cumaná a 1965-66; Universidad de los Andes, Mérida a 1973), da kuma a Puerto Rico (Universidad of Puerto Rico, Río Piedras, 1969). 

 Bincike 
Ayyukan farko na Janzen sun mayar da hankali kan rubuce-rubuce masu kyau na jinsuna a Costa Rica, kuma musamman kan hanyoyin muhalli da ƙarfin hali da juyin halitta na hulɗar dabba da shuka.:  A cikin 1967, alal misali ya bayyana ƙwarewar ƙudan zuma na nau'in ƙudan zume-shuke na Bignoniaceae,  daga cikinsu "irin nau'in fure-fure", wanda Alwyn Howard Gentry a cikin rarraba fure mai suna Type 4 ko "babban bang" dabarun.  Janzen ya gabatar da ra'ayoyi da yawa waɗanda suka yi wahayi zuwa ga shekaru da yawa na aiki ta hanyar masu ilimin muhalli na wurare masu zafi da na matsakaici (duba ƙasa).

Miguel Altieri a cikin littafinsa Agroecology: The Science of Sustainable Agriculture ya ce: "Labarin Janzen na 1973 game da tsarin agroecosystems na wurare masu zafi shine kimantawa na farko da aka karanta game da dalilin da ya sa tsarin aikin gona na wurare masu wurare masu zafi zasu iya aiki daban da na yankuna masu matsakaici".  

A shekara ta 1985, da fahimtar cewa yankin da suka yi aiki a ciki yana fuskantar barazana, Janzen da Hallwachs sun fadada mayar da hankali ga aikin su don haɗawa da sabunta gandun daji na wurare masu zafi, fadadawa (ta hanyar sayen ƙasa) da kiyayewa. Sun yi amfani da taimakon mutanen Costa Rica na gida, suna canza ƙwarewar aikin gona zuwa parataxonomy, kalmar da suka kirkira a ƙarshen shekarun 1980. Ya zuwa 2017, an gano wasu sababbin nau'o'i 10,000 a yankin Conservation Guanacaste godiya ga kokarin parataxonomists.

Ta hanyar shirin DNA barcoding tare da masanin kwayoyin halitta Paul Hebert, sun yi rajistar samfurori sama da 500,000 da ke wakiltar fiye da nau'in 45,000, wanda ya haifar da gano nau'in nau'in da ke kusa da kama da juna waɗanda suka bambanta dangane da kwayoyin halitta da yanayin muhalli.   Janzen da Hallwachs sun goyi bayan shirye-shiryen barcoding na jinsuna a matakin kasa da kasa ta hanyar Instituto Nacional de Biodiversidad (INBio), CBOL (Consortium for the Barcode of Life) da iBOL (International Barcode of life).   

 Tunanin da ke da tasiri 
Janzen an san shi da bayar da ra'ayoyin "da ke da ma'ana da ba na al'ada ba". Wadannan ra'ayoyin sun sami digiri daban-daban na tallafi, amma sanannu ne saboda sun yi wahayi zuwa ga babban bincike mai ɗorewa, kamar yadda aka tabbatar da yawan ƙididdigar yawancin takardunsa na shekaru da yawa bayan an buga su.

Ɗaya daga cikin shahararrun ra'ayoyin Janzen (daga takarda da aka fi ambatonsa)  yanzu an san shi da Ra'ayin Janzen-Connell, kamar yadda Janzen da Joseph Connell suka gabatar da ra'ayi a cikin 1970-1971. Dukansu sun ba da shawarar cewa yawancin bishiyoyi masu zafi, a wani bangare, ga ƙwararrun abokan gaba da ke kai farmaki ga tsaba ko tsiro waɗanda ke kusa da itacen iyaye ko kuma musamman a taru, don haka hana kowane nau'in ya zama mai rinjaye.

Wani ra'ayi mai tasiri  ya fito ne daga takardar Janzen ta 1967 'Me ya sa hanyoyin tsaunuka suka fi girma a cikin wurare masu zafi'.  Ya ba da shawarar cewa duwatsu masu zafi sun fi zama shingen ga rarraba jinsuna fiye da duwatsu masu matsakaici saboda jinsunan wurare masu zafi ba su da ikon jure canje-canje a zafin jiki tare da tsawo, bayan sun samo asali kuma sun rayu a cikin yanayi mai ɗorewa.

A cikin takarda ta 1977 'Me ya sa 'ya'yan itace suka ruɓe, tsaba suka yi kama, da nama sun lalace',  Janzen ya ba da shawarar cewa ƙwayoyin cuta suna ba da abinci mai ban sha'awa (ko aƙalla mai ban shaʼawa) ga ƙwayoyin ƙwayoyin ba kamar yadda samfurin ƙwayoyin halitta ko samfuran sharar haɗari ba, amma a matsayin dabarun juyin halitta don kawar da masu amfani da ƙwayoyin ruwa da kansu. Shaida ta gauraye, kuma yana da wahala a gwada ko mahadi sun samo asali ne don hana wasu ƙwayoyin cuta ko dabbobi, amma an haɗa ra'ayin a cikin nazarin dabbobi masu cin abinci daga mutane zuwa dinosaur.

 Coevolution na shuke-shuke da dabbobi 

 Coevolution na tsarin mutualistic a cikin New World tropics tsakanin nau'in Acacia (Mimosoideae; Leguminosae), v. gr. , [./<i id= Acacia]_cornigera" id="mwrg" rel="mw:WikiLink" title="Acacia cornigera">Acacia cornigera, da tururuwa Pseudomyrmex ferruginea (Formicidae). Acacia spp a cikin Neotropics ana kare su da tururuwa daga defoliation; saboda wannan, ana ba da lada ga tururuwa ta hanyar gabobin musamman da ilimin lissafi wanda Acacia ya samo asali. : 426 
 Spondias mombin (Anacardiaceae) ya rasa masu watsa tsaba na megafauna a cikin Pleistocene. Tsakanin wuta a cikin makiyaya masu budewa da cinyewar iri ta bruchid beetles a cikin gandun daji mai rufewa, S. mombin ba ya da dama. Amma, a yau, a Guanacaste, tsaba suna watsar da White-tailed deer (Odocoileus virginianus) da wasu dabbobi masu shayarwa 15, waɗanda ke ciyar da su galibi a gefen gandun daji, inda bruchids ba su da damar samun tsaba da wuta.

 Maido da mazaunin wurare masu zafi 
dazuzzuka masu bushewa sune tsarin halittu mafi barazana a duniya. A tsakiyar Amurka akwai 550 000 km2 na gandun daji a farkon karni na 16; a yau, ƙasa da 0.08% (440 km2) ya kasance.   An share su, an ƙone su kuma an maye gurbinsu da makiyaya don kiwon shanu,  a cikin sauri a cikin shekaru 500 da suka gabata.

In 1985, realizing that widespread development in northwestern Costa Rica was rapidly decimating the forest in which they conducted their research, Janzen and Hallwachs  expanded the focus of their work. Janzen and his wife helped to establish the Area de Conservación Guanacaste World Heritage Site (ACG), one of the oldest, largest and most successful habitat restoration projects in the world. They began with the Parque Nacional Santa Rosa, which included  of pasture and relictual neotropical dry forest and  of marine habitat. This eventually became the  Área de Conservación Guanacaste, located just south of the Costa Rica-Nicaragua border, between the Pacific Ocean and the Cordillera de Tilaran which integrated four different national parks. Together these house at least 15 different biotopes, viz (mangroves, dry forest and shrubs, ephemeral, rainy season, and permanent streams, fresh water and littoral swamps, evergreen rain- and cloud forests...) and ca. 4% from world's plant, mammals, birds, reptiles, amphibians, fishes and insects diversity, all within an area less than . It is one of the oldest, largest and most successful habitat restoration projects in the world. As of 2019, it consists of . The park exemplifies their beliefs about how a park should be run. It is known as a center of biological research, forest restoration and community outreach.

Maido da mazaunin ba abu ne mai sauƙi ba. Ba wai kawai dole ne mutum ya yi yaƙi da daruruwan shekaru na lalacewar muhalli ba, wanda aka nuna ta hanyar canza tsarin ruwa, da wuya a kawar da makiyaya, ƙasa mai ƙuntata, bankunan tsaba masu ƙarancin manya da masu yadawa, yaduwar masu tsayayya da wuta da rashin jin daɗi daga tsoffin wurare masu zafi na duniya. Har ila yau mutum yana fuskantar matsalolin canza al'ada wanda ya ci gaba da shi, ya amfana daga kuma zai iya zama mummunan tare da irin wannan tsarin.

Saboda wannan dalili an yi la'akari da ACG a matsayin aikin sabunta al'adu, wanda, don bayyana takwaransa na halitta, ya kamata a girma. ACG ta haɗa matakai masu dacewa na gwaji, Maido da mazaunin da ci gaban al'adu.: 89-91  Hanyoyin da aka yi amfani da su sun hada da:

 Maidowa mai aiki, watsawar wucin gadi na propagules daga nau'ikan shuke-shuke na asali zuwa wuraren zama na Guanacaste : 57, 73
 Maidowa ta hanyar wuta, rigakafin farauta da kuma kula da masu cin ganyayyaki : 33, 73
 Ilimi na muhalli da wayar da kan jama'a :  

 Rayuwa ta mutum 
Janzen ta auri masanin ilimin muhalli Winifred Hallwachs, wanda kuma shine abokin aikinsa na bincike akai-akai. Game da Hallwachs, Janzen ya ce, "Mun yi waɗannan abubuwa tare," :-136 da "mun kasance tare sosai wajen fahimtar abubuwa iri ɗaya....Tun da ni memba ne na murya, ana danganta shi da ni. Amma zan ce waɗannan ra'ayoyi da jagororin da tunani da ayyuka suna da sauƙin hamsin da hamsin. " : 134

 Kyaututtuka na girmamawa 
Janzen ya kasance mai karbuwa sau da yawa a Amurka, da kuma a Turai da Latin Amurka; an saka hannun jari na waɗannan kyaututtuka a cikin asusun amincewa na ACG ko wani daga cikin ayyukan kiyayewa a Costa Rica. Kyaututtuka da bambance-bambance da Janzen ya samu sun hada da:

 1975, Kyautar Henry Allan Gleason, Botanical Society of AmericaKamfanin Botanical Society of America
 1984, Kyautar Crafoord: Ilimin muhalli na juyin halitta. Kwalejin Kimiyya ta Royal Sweden
 1985, Kyautar Koyarwa ta Musamman, Jami'ar Pennsylvania 
 1987, The Berkeley Citation for Distinguished Achievement and Notable Service to the University,  Jami'ar California, Berkeley
 1987, Hijo Ilustre de Guanacaste (wanda Gwamnan Lardin Guanacaste ya ba shi) 
 1987, Rubuce-rubucen girmamawa na Duniya 500, UNEP 
 1989, MacArthur Fellowship 
 1989, Kyautar Leidy, Kwalejin Kimiyya ta Halitta ta Philadelphia 
 1991, Kyautar Majalisar Wanda ta Kafa, Gidan Tarihi na Tarihi 
 1992, memba, Kwalejin Kimiyya ta Kasa, Amurka 
 1993, Kyautar Inganta Ingancin Rayuwa na Costa Rican, Universidad de Costa Rica (kyautar tare da W. Hallwachs). 
 1994, lambar yabo ta azurfa, International Society of Chemical Ecology . 
 1995, Kyautar Sabis ta Duniya, Society for Conservation Biology 
 1996, Dokta na girmamawa na Kimiyya, Jami'ar Minnesota . 
 1996, Thomas G. da Louise E. DiMaura sun ba da kujerar kujerar, Jami'ar Pennsylvania 
 1997, Kyautar Kyoto (Fasahar Kimiyya ta asali), Gidauniyar Inamori 
 2002, Albert Einstein World Award of Science,  Majalisar Al'adu ta Duniya, (Mexico) 
 2002, Mai Girma na Ƙungiyar Kula da Halitta (da Tsaro) (ATBC) 
 2006, Winner, National Outdoor Book Awards (NOBA), don 100 Caterpillars: Hotuna daga dazuzzuka na Tropical na Costa Rica (2006), Design & Artistic Merit Category.
 2011, BBVA Foundation Frontiers of Knowledge Award of Ecology and Conservation Biology don aikinsa na farko a cikin ilimin muhalli na wurare masu zafi da kuma gudummawarsa ga kiyaye yanayin halittu na wurare masu haɗari a duk duniya, yana amfani da fahimtar hulɗar shuka da dabbobi. Janzen ya amince da rawar da matarsa da abokin bincike na dogon lokaci, masanin ilimin muhalli Winnie Hallwachs, ya taka rawar da aka sani.
 2013, Gidauniyar Wege ta ba da tallafin dala miliyan 5 ga Asusun Kula da dazuzzuka na Guanacaste (GDFCF), wanda Dan Janzen da Winnie Hallwachs suka kafa a shekarar 1997.
 2014, Blue Planet Prize, daga Asahi Glass Foundation 

 Dubi kuma 

 Daidaitawar muhalli
 Ra'ayin Janzen-Connell

 Littattafai 
Wadannan sune zaɓin wallafe-wallafen Janzen waɗanda ba a lissafa su ba.







 manazarta 

 Haɗin waje 

 Costa Rica: Aljanna da aka dawo da ita, Bayanan Dan Janzen a cikin Halitta, Gidauniyar MacArthur, WNET (Tarihin Talabijin: New York, NY, 1987)  
 Shafin koyarwa a Jami'ar Pennsylvania

Rukuni:Rayayyun mutane
Rukuni:Haifaffun 1939
Rukuni:Shafuka masu fassarorin da ba'a duba ba