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Is biology an autonomous science?
第6單元:生物學是物理科學的延伸嗎? Is biology an autonomous science? 周成功 生物科學是不是像其他科學一樣有一些本質或是根本上的差異? 本著作除另有註明外,採取創用CC「姓名標示-非商業性-相同方式分享」台灣2.5版授權釋出
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What is scientific method?
大胆的假設 小心的求証 探索科學重要的研究方法就是大膽假設小心求證,來自胡適的名言。 是不是真實反映出嚴格的科學方法?小心求證是必要的作法,是不是假設越大膽,科學研究做得越好呢? 我們來回顧西方討論科學方法的簡要歷史。
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Sir Francis Bacon (1561-1626) Bacon’s Methodology of Science
Examine an large number of cases Using Induction Employing no pre-judgement, i.e. not theory- or hypothesis-driven 最早提出科學方法的西方哲學家是培根,他提出「歸納法」,也就是觀察很多現象,過程中不要有預設的立場與判斷,歸納其中的規律性。
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Galileo Galilei Italy, 1564-1642
Galileo and Shakespeare were born the same year. Experiments and instruments Galileo disproved Aristotle’s hypothesis that heavy objects fall with greater speed than light objects. 16世紀另一位偉大的科學家伽利略,第一次利用望遠鏡觀察星空,另外就是在比薩斜塔利用實驗證明或推翻行之有年的理論,實驗與儀器變成重要的科學方法。 Electron
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Sir Karl Popper (1902-1994) 1902: Born in Vienna
1945: The Open Society and its Enemies 1946: London School of Economics 1949: University of London 1959: The Logic of Scientific Discovery 1963: Conjectures and Refutations: The Growth of Scientific Knowledge 1965: Knighted by Queen Elizabeth II 科學哲學家開始反思,科學發現背後是否有共通的法則? Karl Popper在1959年的英文版著作”the Logic of Scientific Discovery”他想要從傳統科學史的事件找到科學發現背後有沒有邏輯法則。 5
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The principle of Induction (歸納法)
If a large number of swans have been observed under a variety of conditions and all swans were seen as white, then by induction all swans have the property white. Valid general laws can be inferred from true observation statements. But, ….. Vera Buhl 從培根開始提出的歸納法是被認為獲得科學知識的重要方法,但是Popper提出不同看法,他舉了一個例子:利用歸納法,全世界的天鵝都是白色的,但是知識本身不會是確切的,因為…
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有一隻黑天鵝的存在,不管觀察到再多的天鵝出現,利用歸納法推論的結論就被推翻,因此歸納法不會是確切的知識。
Jean-Pol GRANDMONT
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Falsification Science progresses by eliminating theories that have been falsified. A scientific theory cannot be shown to be true. But some scientific theories do have varying degrees of success. They resist falsification. Scientific theories are those that can be falsified. Good scientific theories do not make themselves immune from falsification by use of ad hoc hypotheses Popper提出一個重要評斷科學的準則就是否證:falsification 紅色字是我覺得最有收穫的一句話:Scientific theories are those that can be falsified. 科學家努力否證現有知識系統理論,所有能叫做科學理論就是可以被推翻否證的理論。 例如演化論的爭議,它是眾多解釋生物現象的理論之一,另有其他理論如創造論,根據考古學家挖掘的證據,演化可能存在;一但有新的證據理論還是可以修改;演化論雖然不能在實驗室重複或證明,但是利用演化論解釋歷史的過程、場景,而且理論可以被否證、修改。 另一方面,創造論的證據,例如聖經,上面的文字是無法隨意更動的,因此我們可以根據否證的方式決定是否為科學的範疇,在科學範疇外的創造論,我們不進行討論。
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Thomas S. Kuhn (1922-1991) The Structure of Scientific Revolutions
The University of Chicago Press, 1962. No reference to Popper Popper的否證是科學方法上重要的思維。 另一位科學哲學家孔恩(Thomas Kuhn)在1962年寫了一本書”The Structure of Scientific Revolutions”,他用了物理學的範例檢討物理學發展過程中的科學革命,有個內在的結構存在。 Written at Berkeley. Kuhn: theoretical physicits. 1st exposure to history of science in an experimental college course (phys. Sci. for non-scientists) in Changed his career plans from phys. To hist. Of sci.. What was it like to think scientifically in periods when canons of sci. thought v. diff. Than today. Center for Adv. Stud. In Behavioral Sci No awareness of Popper, no citations in 1962, though may have heard Popper’s lectures at Harvard in early 1950s. But he did note Popper in the 1969 Postscript, his essay in Criticism and the Growth of Knowledge (Cambridge, 1970). In the postscript he says I am not a relativist, despite what critics like Popper and others said he said.
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Immature Science Revolution Crisis Normal Science Anomalies
Kuhn’s History of Science Descriptive Project: Immature Science Revolution Crisis Normal Science 此內在結構包括在不是成熟階段的科學,為了解釋科學現象會出現不同理論,他將之稱為科學的戰國時期,如果有一個重要的突破,科學革命產生新的理論,將會把戰國時期的這種理論總合,孔恩稱為「典範」,所有的研究活動都會圍繞在典範下,形成常態科學;當科學活動產生的結果跟典範再次發生衝突,大部分科學家會不太願意公布,第一個質疑自己,直到典範無法作解釋,進入危機時期,等待新的典範出現。孔恩認為這是過去300年科學進展的過程與科學革命的結構。 Anomalies 10
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Grazia Borrini-Feyerabend
Paul Feyerabend ( ) Against Method (1975) 第三位科學哲學家1975年出了一本書”Against Method”他認為對科學家而言是沒有科學方法的。 Grazia Borrini-Feyerabend 11
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What you have seen? A rabbit or a duck?
他舉了一個例子,這張圖像是鴨子還是白兔? 需要自己決定。 因為沒有一個客觀的判準誰是對或錯,
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It is the principle that anything goes” (AM 28)
Feyerabend There is no rationally justifiable scientific method. Scientists do (ought to do?) whatever does not inhibit progress: Theory acceptance is ideological, not rational “…there is only one principle that can be defended under all circumstances and in all stages of development. It is the principle that anything goes” (AM 28) 我們所接受的科學理論都是意識形態(iedology)不是理性的決定。 這是相當極端的看法。 他的結論是,對科學家而言怎麼做都行,成者為王敗者為寇。
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Does biology have the same scientific characters as physics??
生物學已被視為是一門科學,是否與物理科學相同? 生物與物理是否具有完全相同的特質?
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古典物理學家怎麼“看”生物學?
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“Postage stamp collection”
Ernest Rutherford 拉塞福,用放射性α分子打金箔, %順利通過金箔,只有0.0001%反射回來,他歸納出原子模型,原子大部分的質量聚集在非常微小的區域,剩餘的區域是空的,只有當α分子打到原子核才會反彈,是建立原子模型的科學家。 他非常看不起生物學家,認為生物學家做的事情就是「集郵」,將採集回來的生物分門別類。
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“…there are no ‘absolute phenomenon’ in biology
“…there are no ‘absolute phenomenon’ in biology. Everything is time-bound and space-bound…” Max Delbruck 另一位物理學家認為生物學沒有一個絕對的理論,所有的事情都是時間、空間的限制;提出者是分子生物學的開山祖Max Delbruck
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Is biology an autonomous science?
Whether and how biology differs from the other natural sciences, such as chemistry or physics? 生物與物理有什麼差別? 如果有,差別是什麼?
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Biology: a science with history
"Nothing in biology makes sense except in the light of evolution.“ T. Dobzhansky 最偉大的演化生物學家之一Dobzhansky提出:演化是歷史的過程。
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Evolution of galaxies is transformational , not variational evolution.
Is evolution of galaxies (history of universe) equivalent to biological evolution? Evolution of galaxies is transformational , not variational evolution. Radioactive decay, controlled by physical laws is a teleomatic (spontaneous toward the end state) process, not a teleonomic one (goal-directed). 生物學是一個帶著歷史的科學,物理也討論歷史,例如地球的起源,宇宙的起源,討論物理現象的歷史與討論生物現象的歷史是截然不同,對歷史特質的不同認知嗎? 銀河系的演化是一種自然出現自然發生的過程,這個過程跟生物中自然發生過程的最大不同是「目的」;我們要討論在生物界自然發生過程的目的,但是不會討論宇宙中星雲星球出現的目的,他們是「過程」。
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物理學:科學的模範生 從加利略到牛頓所建立科學的典範 Feyman: Characters of Physical Law (天下文化)
不受時空限制的物理定律. 物理定律不討論“運氣”的角色 科學方法就是嚴格控制所有變數的實驗 “觀察”與“比較”是不太科學的方法 Feyman: Characters of Physical Law (天下文化) 物理是科學的模範生。 科學哲學、科學革命都是物理的範疇,代表是對科學的一種崇拜。 從伽利略到年頓建立科學的典範有下列特徵: 1.不受時空限制,例如牛頓力學在地球上F=ma 、火星上F=ma、五十億年前地球F=ma。 2.不討論運氣。物理定律不討論運氣。 3.科學方法就是嚴格控制變數的實驗。 4.觀察與比較都不是科學的方法 大家有興趣可以看「物理定律的特性」。
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對生物學來說 生命源起於三十八億年前的地球 永遠準備“例外”的出現 對現象的解譯常有多重可能的臆測,而非完全依賴嚴格的物理律.
時空的限制 永遠準備“例外”的出現 對現象的解譯常有多重可能的臆測,而非完全依賴嚴格的物理律. Two key questions in biology. “How?” or “how come?” “Why?” or “what for?” 對生物學來說,有時空的限制,也就是說生命的現象是源起38億年前的地球。 生物學要永遠準備有例外的出現,永遠不要相信某個酵素只是催化單一化學反應。現在有很多蛋白在細胞中的角色是多元的,可能是轉錄因子、可能是催化者。 在生物學中有兩個重要的問題是必須同時能回答的:How and Why
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兩種類型的生物學 . “How?” or “how come?” “Why?” or “what for?”
功能生物學 (Functional Biology) “Why?” or “what for?” 演化生物學 (Evolution Biology) How說的是功能,Why說的是演化。 要了解任一生命現象有功能與演化生物學的面向。
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Prediction (預測) 物理律最重要的條件! 從天王星繞日軌道的觀察不符合牛頓力學的計算,推論應有一尚未被觀察到的行星存在!
根据相對論,光經過一個重力場時会產生偏折的現象. For functional biology: yes! For evolutional biology: probably no! 討論未來的生命型式在自然界会如何改變是沒有意義的! 傳統討論科學方法,用物理當模範生,物理科學最重要的特徵就是有預測能力。 比如說,觀察到的現象與典範違背,是推翻典範還是懷疑自己? 物理學家觀察天王星繞日軌道,發現與牛頓力學計算的軌道不符合,第一件事情是觀察方式是否錯誤?接下來看為什麼與預測不符合?所以不會先懷疑牛頓力學的正確性,接收其正確性而修改自己的觀測;如果牛頓力學是正確的,但觀測到的軌道不符合,表示一定還有尚未觀察到的行星因素,如果加進來就可以跟預測的一樣,因此科學家用望遠鏡尋找尚未觀察到的行星,也就是海王星的發現。 另一個重要的預測能力就是相對論。相對論提到光穿越重力場會產生偏折現象。在1919年東非發生的全日蝕,科學家想根據相對論的預測來觀察太陽背後行星的位置;因為全日蝕太陽背後的星光如果經過太陽(大型重力場),光線轉彎的話,地球就可以看到。對功能性生物,在實驗過程會去預測這個結果可能是什麼樣的結果,對演化生物學,預測這件事情是沒有意義的。 討論100年之後的生命形式其實是毫無意義的事情,如果我們能掌握分寸,就可以對生物學更清楚的探索。
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Solar eclipse of 29 May 1919 Newton: deflection = 0.87 arc seconds
Einstein: deflection = 1.74 arc seconds Observations: Crommelin expedition 1.98 0.16 Eddington 1.61 0.40 Einstein is overnight sensation 英國科學家要觀察全日蝕太陽背後星光是否轉彎(折射)的現象。 根據牛頓力學的預測,星光折射是輕微的,但是愛因斯坦預測的折射是強的;觀測結果是接近愛因斯坦所預測的。 具有強大的預測能力,是判斷科學理論的重要準則,只有在物理科學中才成立。 One wonders how Einstein would have been treated by history if either of the 1912 or 1914 expeditions had been successful. Until 1915, his reputation was riding on the incorrect value of 0.87 arc seconds. As it turned out, the 1919 British expeditions to Sobral and Principe were to prove his later calculation to be right. And the rest, as they say, is history. Peter Coles, Einstein, Eddington and the 1919 Eclipse, Proceedings of International School on "The Historical Development of Modern Cosmology", Valencia 2000, eds V.J. Martinez, V. Trimble & M.J. Pons-Borderia, ASP Conference Series, in press ( Peter, Einstein, Eddington and the 1919 Eclipse, arXiv:astro-ph/ ; 2001
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Teleology(目的論) 討論目的是生物學中一亇重要的問題! 物理科學不討論物理現象有什麼目的!
我們會不会討論河床中圓滑卵石存在的目的? 讓它們更容易安逸地躺在河床上!? 雖然物理科學也有歷史過程,但是是不討論其目的的。討論目的是生物學中重要的面向。 例如看到河床中有卵石,有其歷史過程:大石頭經過上游河水的沖蝕而到下游變成平滑圓形的石塊,但是不會討論變成這樣的形狀有什麼目的,我們不會說卵石變得圓圓的是想要安逸的躺在河床上,對物理現象是不討論目的的。
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Population (群體) 我們會不会說這是“一群”氫原子? No!對物理學家,宇宙中每一亇氫原子都是完全相同無可分辦的!
但是對生物學家,“一群生物”中每一亇生命亇體都是獨一無二的! 物理跟生物很大的差別就是「群體」。 對物理學家而言一顆氫原子與一群氫原子每一顆的性質是相同的;但是對生物學家而言每一個個體是獨一無二的。
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Is cause the same thing in functional and evolutionary biology?
討論原因的時候,對功能性生物或是演化生物學是不是同一件事情? 明顯地,NO。
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侯鳥在秋天為什麼要向南飛? 北方秋天,候鳥往南飛,為什麼?
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侯鳥在秋天“為什麼”要向南飛? How? and Why? 為什麼要往南飛? How與Why都是為什麼,但是背後的意涵是不同的。
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How? 外在環境如氣温,日照等因素的改變。 內在生理因素如腦中感光 (温) 受體誘發行為的改變。 怎麼作到的(原因)。 生理、生化的機制。
不問這個機制怎麼來的 (歷史)! 當我們問How 也許候鳥可以感知環境溫度的變化、或日照的長短。 也許細胞中有受體可以感光或感溫,誘發行為的改變。 怎麼做到南飛的?其內在生理、生化機制、分子生物的機制,讓候鳥感知環境中的陽光、溫度、日照的改變而啟動行為層次的機制。 但是我們不問機制怎麼來的,或是這個機制有什麼目的。 但是問這些機制出現在候鳥身上的目的,就是有意義的問題。
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Why? 每隻候鳥都攜帶了一套獨特的“遺傳程式” 這套“遺傳程式”從何而來? 為什麽猫頭鷹不南飛?
每個候鳥都帶了獨特的遺傳程式,賦予它們往南飛的行為。 這套儀傳程式從何而來?為什麼貓頭鷹不往南飛?
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圖片來源:加拿大魁北克政府官網 貓頭鷹為何不往南飛?
貓頭鷹抓小動物,北方的冬天食物來源不匱乏,但是候鳥在本地的冬天抓不到食物,牠必須要往南飛才能生存。 圖片來源:加拿大魁北克政府官網
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候鳥吃昆蟲,天寒蟲少,必須演化出一套獨特的“遺傳程式”,讓他們在變天前往南飛才能存活下來 (生態的原因)。
猫頭鷹不需要這套天冷南遷的“遺傳程式”! 候鳥吃昆蟲,天寒蟲少,必須演化出一套獨特的“遺傳程式”,讓他們在變天前往南飛才能存活下來 (生態的原因)。 演化的原因:解譯了歷史! 我們談生物演化的目的,是希望解釋生物演化的歷史。
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生物學的歷史面向 -和物理最大的不同 根據現存的種種蛛絲馬跡去重新建構或還原歷史事件。 永遠是個有些根據的理論,但永遠無法用嚴謹的實驗証明!
生物的歷史(演化) —幫助我們去暸解生物世界一個重要的基石 生物學的歷史面向,就是根據現存的蛛絲馬跡重新建構演化的歷史事件;才能掌握生命現象的全貌,在談生物演化的過程往往是有根據的理論,是無法用如物理方式嚴謹的實驗去證明,雖無法證明,不表示不重要。因為生物的歷史演化是幫助了解生物世界基石。
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“ A physicist looks at biology”
生物學:一亇帶着歷史經驗的科學 “Any living cell carries with it the experiences of a billion years of experimentation by its ancestors” “ A physicist looks at biology” Max Delbruck, 1949 Max Delbruck說的一句話:每一個活著的細胞身上都攜帶著祖先在過去幾十億年經歷無數實驗、經驗的累積。
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"Nothing in biology makes sense except in the light of evolution."
T. Dobzhansky
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Salvador Luria and Max Delbruck (1969 Noble laureate in medicine)
1943 – Studies of bacterial resistance to bacteriophage T1 Adaptation or Spontaneous mutation 生物學中有兩個極端的實驗。 第一個實驗是Luria與Delbruck(兩位是分子生物學的開山祖師,於1969年得諾貝爾獎)在1943年,他們研究演化論的三個重要觀念:變異、個體差異可遺傳、選擇。在演化論中已經預設一個觀念是「個體差異是在選擇之前出現」,適合於天擇的人才會存活;但是有沒有可能是有些個體是天擇中改變自己? E. Coli受到噬菌體的感染,細菌被殺死,總有幾個細菌會活下來,這群細菌是在噬菌體之前就存在,還是在噬菌體入侵後趕快產生抗菌性?這是演化論最重要的問題。那麼根據演化論,這些具有抗菌性的細菌是先前就存在的變異。 如何證明? Luria與Delbruck做了一個簡單的實驗證明抗菌性的細菌早在噬菌體入侵前即存在。
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re-infect-still resistant Phage-resistant E.coli
adaptation E. Coli culture (wild-type) Subculture + excess T1 phage plate Pick resistant colony re-infect-still resistant Phage-resistant E.coli 李承維 Question: Was this resistance acquired through adaptation to exposure to the phage (mutated to survive) OR was it a spontaneous mutation which occurred randomly regardless of exposure (i.e. it was there before exposure to phage)? 假設有一千萬個細菌,其中有三個細菌是對噬菌體有抗菌性,把這一千萬個細菌分成 十管,每一管有一百萬個細菌,原來存在抗菌性的細菌分散在三管,繼續培養從一百 萬長到一千萬個,再加入噬菌體,檢查十管中出現抗菌性的細菌數目;假如是噬菌體 入侵後才改變遺傳程式出現抗菌性,那麼十管出現抗菌性細菌數目應該是相當的,而 實際上他們發現抗菌性細菌數目各管有多有少、是震盪的分布。 Adaptation Versus Spontaneous Mutation Key concept in the theory of evolution! 39
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re-infect-still resistant Phage-resistant E.coli
resistant bacteria exists even they have NEVER been exposed to T1 when T1 added, T1-resistant bacteria selected for spontaneous E. Coli culture (wild-type) Subculture + excess T1 phage plate Pick resistant colony re-infect-still resistant Phage-resistant E.coli 所有這些變異的個體是還沒選擇之前就存在的;適應環境的變異不是為了適應而產生 。這是很有名的實驗,我認為是生物學研究中最elegant實驗,是針對一個重要的問題 ,設計一個實驗回答,得到一個清楚的結果。 李承維 40
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I II III IV V VI VII VIII Luria-Delbruck ‘Jackpot’; fluctuation test
1943 Salvador Luria and Max Delbruck used E. coli and T1 phage to test hypothesis (adaptive vs spontaneous) Luria-Delbruck ‘Jackpot’; fluctuation test I II III IV V VI VII VIII Cultures Media and phage plates 李承維 41
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phage adaptation 李承維 Resistance is the result of adaptation to the selective pressure (phage). Every bacteria has a small but constant chance of acquiring resistance upon exposure to T1 phage. If true, the number of resistant cells should only depend on the # of bacteria and phage. Hypothesis: if constant amount of bacteria and phage are added and incubation time is constant, then all plated cultures should adapt similarly, resulting in similar #’s of resistant colonies on the plates (no fluctuation) 42
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Resistance is a result of spontaneous, random
李承維 Resistance is a result of spontaneous, random mutations even in the absence of phage If so, then there will be a great fluctuation (differences) in the number of resistant colonies when plated 43
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resistance occurs as a result of random, spontaneous
Conclusions: resistance occurs as a result of random, spontaneous mutations that happen at various time points BEFORE exposure to selective agent.
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The Nobel Prize in Physiology or Medicine 1959
“for their discovery of the mechanisms in the biological synthesisi of ribonucleic acid and deoxyribonucleic acid” Seveto Ochoa Arthur Kornberg 1959年Arthur Komberg因發現DNA聚合酶得到諾貝爾獎。 KANO PHOTO
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Kornberg’s enzyme- DNA polymerase
Polymerization 3’-5’ exonuclease “editing” 5’-3’ exonuclease “nick-translation”
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The bacterial chromosome and its manner of replication as seen by autoradiography. (John Cairn. J Mol Biol. 6: ) 1. One DNA molecule/chromosome per bacteria 2. One replication origin per chromosome (bacteria/viruses). 但是另一位科學家John Carin1963年第一次發現E.Coli的染色體是圓形的,他很有意思,他想Arthur Komberg所發現的DNA聚合酶是不是真的製造DNA複製,既然要挑戰權威,就需要有證明。 如果在大腸桿菌中讓DNA聚合酶突變,讓其活性降低,如果不是負責DNA複製的酵素,細胞應該能繼續存活;Carin跟他的學生一起研究是否有其突變種存在,他們一個個挑選突變的大腸桿菌,這位學生日以繼夜很辛苦的挑選,終於在一千八百多個培養皿中發現有種酵素活性很低,但是卻能生長得很好(ration+luck是偉大科學家缺一不可的要素),證明Arthur Komberg所發現的DNA聚合酶(pol I)不是負責DNA複製的酵素,而是polymerase III。 Interpretation of the autoradiogram:
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Is Kornberg enzyme really responsible for DNA replication in vivo?
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Paula de Lucia & John Carins Nature 224: 1164-1166 (1969)
Isolation of an E. coli strain with a mutation affecting DNA polymerase Paula de Lucia & John Carins Nature 224: (1969) 這位學生Paula deLucia,發表於1969年找到E. Coli真正負責DNA複製的DNA聚合酶。
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學術發現的四個階段 法國數學家朋加萊 (H. Poincare)
準備 (Preparation) 潛伏 (Incubation) 豁然開朗(Illumination) 証明 (Verification) 大膽假設、小心求證,所有的假設都必須是可靠的假設。 分享科學方法的幾位大師不同說法: 數學家朋加萊的看法: 準備:廣泛閱讀,準備背景知識, 潛伏:任何重大問題的突破前都有個潛伏期,豁然開朗之後再去證明
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博蘭霓(Michael Polanyi 1891-1976) )
影響一個人研究最重要的因素,是他不能明說、從他的文化與背景中經由潛移默化而得的支援意識 (subsidiary awareness) 未可明言的知識 (tacit knowledge) 支援意識是隱晦,無法明確描述 邏輯與方法論不能對創作活動中最重要的關鍵加以界定,更談不上指導了! 博蘭霓認為:從文化背景中潛移默化得到的支援意識,如果沒有很強大的準備期,光只是假設誰的膽子大是沒用的,提出假設的過程當中背後的支援意識是很重要的角色,也就是未可明言的知識;讀書常常覺得沒有用,因為書上的道理跟生活的工作風馬牛不相及,但是走過必留下痕跡,在潛意識當中累積著未可明言的知識,在日後碰及問題時會變成重要的看法。 真正的邏輯或方法論是不能在創作活動中界定,光是懂科學方法但是沒有支援意識是無法幫助創作活動的。
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古今之成大學問、大事業者,必經過三種之境界:
王國維 / 人間詞話 在東方也有類似的看法: 王國維,清末明初的國學大師,他的一本書:人間詞話,同學可能都聽過。
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昨夜西風凋碧樹,獨上高樓,望盡天涯路。 晏殊、蝶戀花 第一境界: 也就是準備期
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衣帶漸寬終不悔,為伊消得人憔悴。 柳永、鳳棲梧 第二境界:
也就是潛伏期,問題苦思不解時,在得到答案之前思考的過程中,潛意識不斷提取過去經驗與背景知識。
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眾裡尋他千百度,驀然回首,那人卻在燈火欄柵處。
辛棄疾、青玉案(元夕) 第三境界: 豁然開朗、解決問題。不經過苦思找尋方法的過程,準備與潛伏的階段,就不會有豁然開朗的境界。因此東西方有大學問的人對於學術發展的思維是類似的。
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學術研究是一條寂寞而漫長的道路,沒有一種出自內心的召喚,沒有那種圈外人嗤之以鼻的「陶醉感」,可能還是去從事學術研究以外的事比較好
學術研究是一條寂寞而漫長的道路,沒有一種出自內心的召喚,沒有那種圈外人嗤之以鼻的「陶醉感」,可能還是去從事學術研究以外的事比較好! 每個人的生命都是一次獨一無二的經歷,可以追求的事物很多,但是都該懷抱著熱情去作才值得。 我在陽明大學教書時給準備研究所學生的一封信。 給準備投考研究所同學的一封信.1990
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Physicalism vs Vitalism
To explain all biological process in term of physical and chemical laws. Living organism had some constituent that distinguished it from inert matter.
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Organicism A whole is more than the sum of its parts
Living beings are not just piles of characters or molecules, because their function depends entirely on their organization, their mutual interrelations, interactions, and interdependencies. The genetic program. New properties emerge at higher levels of integration which could not have been predicted from a knowlede of the3 lower-level components (emergence) Organicism is antireductionism and yet remained mechanistic.
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The fundamental differences between living organisms and inert matter
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The complexity of living systems
An open system. The homeostasis is made by feedback control. Compare to world weather or galaxy, the complexity of living systems exists at every hierarchical level. They act as though they were a homogeneous entity. Their characteristics cannot be deduced from the most complete knowledge of the components.
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Organization into populations
For Plato, variable classes of entities consist of imperfect reflections of a fixed essences. In 1859 Darwin introduce the entirely new concept of variable populations composed of unique individuals. Every water molecules are identical. Every human being are unique (different).
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Possession of a genetic program
Why organisms are unique? They have a mechanism for the storage of historical acquired information. A historically evolved genetic program coded in the DNA of the nucleus. Genotype versus phenotype, The genotype (genetic program) is the product of a history that goes back to the origin of life and thus it incorporates the “experiences” of all ancestors. The genotype endows organisms with the capacity for goal-directed processes and activities.
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Comparative versus experimental method
Functional biology The ever-repeated question is “How come” How does it function? How does something operate? The chief technique is the controlled experiment just like chemist or physicist does. Evolutionary biology The basic question is “Why?” or “What for?” Every organism is the product of a long history Everything is time-bound and space-bound There are no absolute phenomena in biology Observation and comparison
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What is the cause of bird migration?
An extrinsic physiological cause Cold air or short daytime. An intrinsic physiological cause Photo- or temperature- sensor tie in with migration A genetic cause An acquired genetic program in the course of the evolutionary history An ecological cause Insect eater, must migrate before the winter come The owl?
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Proximate versus Ultimate causes
Proximate cause: concerned by functional biologist. Photo- or temperature- sensor tie in with migration Ultimate cause: concerned by evolutionary biologist. An acquired genetic program in the course of the evolutionary history Ultimate cause Insect eater, must migrate before the winter come The owl?
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Concepts in biology is entirely different from that of the physical sciences and cannot be reduced to it. “meiosis” plays in the life of an organism cannot be described only by physical law or chemical reaction, even though physico-chemical principles are operating!
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Law versus theories No law in biology as the law in physics.
F=MA E=MC2 Many theories, but there is hardly a theory in biology with no exception. Life history theory
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Prediction Is an essential qualification for physical law!
Predict the existence of one unknown planet (Neptune) due to the abnormal movement of Uranes. Predict the path of light would be curved when it pass through a big mass. For functional biology: yes! For evolutional biology: probably no!
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Teleology From egg to adult: a process with a purpose or with a predetermined state? Important question in biology Not in physical sciences More smoothing and rounding does not make a pebble better adapted for its existence in a river bed!
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Uranus revolves around the Sun once every 84 Earth years
Uranus revolves around the Sun once every 84 Earth years. Its average distance from the Sun is roughly 3 billion km (about 20 AU). The intensity of sunlight on Uranus is about 1/400 that on Earth. Its orbital elements were first calculated in 1783 by Pierre-Simon Laplace. With time, discrepancies began to appear between the predicted and observed orbits, and in 1841, John Couch Adams first proposed that the differences might be due to the gravitational tug of an unseen planet. In 1845, Urbain Le Verrier began his own independent research into Uranus's orbit. On September 23, 1846, Johann Gottfried Galle located a new planet, later named Neptune, at nearly the position predicted by Le Verrier.
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For biology- Life was originated around 3.8 billions years ago and was restricted to the earth! Always has exceptions. Explanation usually were not based on universal laws but rather were pluralistic. Is biology a “dirty science”? Not much better than “postage stamp collection.”
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版權標示頁
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作品 授權條件 作者/來源 2010/09/27 visited 2010/0927 visited Electron /09/27 visited LSE library /09/27 visited Vera Buhl /09/27 visited Jean-Pol GRANDMONT 2010/09/27 visited
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作品 授權條件 作者/來源 Max Delbruck T. Dobzhansky
2010/10/26 visited Grazia Borrini-Feyerabend /09/27 visited Thomas Kuhn 2010/10/26 visited “Postage stamp collection” Ernest Rutherford “…there are no ‘absolute phenomenon’ …..” Max Delbruck "Nothing in biology makes sense ……...“ T. Dobzhansky
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作品 授權條件 作者/來源 臺灣大學動物所 李承維
Peter, Einstein, Eddington and the 1919 Eclipse, arXiv:astro-ph/ ; 2001 2010/10/27 visited 原為加拿大魁北克官網圖片 “Any living cell carries with it the experiences of a billion…” Max Delbruck 臺灣大學動物所 李承維
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作品 授權條件 作者/來源 臺灣大學動物所 李承維 P52~P55 摘錄至人間詞話 清末 王國維 人間詞話
臺灣大學動物所 李承維 KANO PHOTO /09/27 visited 2010/09/27 visited John Cairns, The bacterial chromosome and its manner of replication as seen by autoradiography, Journal of Molecular Biology, Vol 6, ; 1963 Isolation of an E. coli Strain with a Mutation affecting DNA Polymerase PAULA DE LUCIA & JOHN CAIRNS, Isolation of an E. coli Strain with a Mutation affecting DNA Polymerase, Nature 224, 1164 – 1166; 1969 P52~P55 摘錄至人間詞話 清末 王國維 人間詞話
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作品 授權條件 作者/來源 P56 摘錄至給準備投考研究所同學的一封信 1990 給準備投考研究所同學的一封信
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