Transcript 投影片 1

生命綿延的數學性: 另一種思維習慣
(德語世界的科學事件之一)
Carl Friedrich Gauss:

(1777, Brauschweig - 1855, Göttingen)


高斯
數學是科學的皇后
狐狸的足跡
楊倍昌
1
 中國和西方的科技在1450年到1600 年間仍有並駕
齊驅的樣子，之後西歐突出，才使中國望塵莫及。?
(李約瑟難題)
黃仁宇轉述李約瑟的話, in: 放寬歷史的視界 1988, 允晨叢刊、台北, p:94
 中國一百年來的革命，已於1980 年代完成。期間
最大的一個收穫，則是今後這個國家已能在數目字
上管理 (mathematically manageable) 。
黃仁宇: 放寬歷史的視界 1988, 允晨叢刊、台北, p142
 是嗎? (BC)
2

Johann MENDEL (der Vorname Gregor wurde ihm nach seinem Eintritt ins
Kloster verliehen), geb. 1822 in Heinzendorf (im deutschen Teil des damals
österreichischen Schlesiens), Abt in Brünn, gest. 1884, publizierte 1866 (?)
eine zwar kleine aber inhaltsschwere Schrift mit dem Titel “VERSUCHE
ÜBER PFLANZEN-HYBRIDEN.
3
http://www.mendel-museum.org/
資料很完整的網站:
http://www.mendelweb.org/MWtoc.html
4
In the Footsteps of Mendel
by Margaret Hermánek Peaslee
Professor of Biology and Vice President for Academic Affairs
University of Pittsburgh at Titusville
http://www.mendelweb.org/MWpeaslee.html
5
在孟德爾的花園裡
1865+35=1900

他想要回答什麼問題 ?

為什麼結果被埋沒近 (35) 年?

是什麼認知環境，讓後人了解到孟德爾
研究的重要性?
"gelb x gelb = grün ...wenigstens manchmal"
6
很完整的討論:
http://www.weloennig.de/mendel.htm
 Warum seine Entdeckungen 35 (72?) Jahre
ignoriert wurden
 Ein paar kritische Kommentare von Pionieren der Genetik
sowie weiteren Biologen und Biologiehistorikern zur
Wirkung des Darwinismus auf die biologische Forschung
 Why his discoveries were ignored for 35 (72)
years
 Some critical comments about the effects of Darwinism on
Biological Research by Pioneers of Genetics as well as
further Biologists and Historians of Biology (German with
English Summary)
7
http://www.weloennig.de/mendel.htm

After two lectures in 1865, Mendel published his famous Pisum-treatise
VERSUCHE ÜBER PFLANZEN-HYBRIDEN in 1866. His work was
quoted at least 14 times before 1900, the year of its 'rediscovery'. There
were references in such widely distributed works as Focke's DIE
PFLANZEN-MISCHLINGE (1881), THE ENCYCLOPAEDIA
BRITANNICA (1881) and the CATALOGUE OF SCIENTIFIC PAPERS
OF THE ROYAL SOCIETY (1879). The treatise had been sent to the
libraries of some 120 institutions including the Royal and Linnean Society
of Great Britain. Moreover Mendel had 40 additional reprints at his
disposal, many of which he sent to leading biologists of Europe. In fact,
professor Niessl (1903 and 1906) emphasized that Mendel's work was "well
known" at his time.
8
是什麼東西引起孟德爾如此大的興趣，讓
他願意花費八(?) 年時間進行植物雜交實
驗?

在費曼之前 – 二十世紀的科學簡史; 陳恒安譯, 究竟, 台北
(2002).
Ernst Peter Fischer (1995), Einstein & Co.: Eine kleine
Geschichte der Wissenschaft der letzten hundert Jahre in
Porträts.

或者他只是無聊找事做?
9
Which date is correct?

1865, Mendel gave Lectures on “Experiments in
Plant Hybrids” at the February and March
meetings of the Natural Science Society (Brno).


Vorgelegt in den Sitzungen vom 8. Februar und 8. März 1865) ; 9.
Februar in Brünner Tagblatt.
1866, Mendel published his lecture, a work that
was to establish him as “the father of genetics”.

Versuche über Pflanzen-Hybriden, in Verhandlungen des
naturforschenden Vereins Brünn 4, 3 -47 (Nachruck; Weinheim
1960).
http://www.mendelweb.org/MWGerText.html
http://www.weloennig.de/mendel.htm
10
Why to say after 72 years?
• Fisher RA (1936), a mathematically inclined
scientist, was to deal with the problem of
Mendel’s data being “too good”, it is impossible
to him that the expected and actual data could be
so similar.
• In the case of the yellow x green: The total
number of seeds scored was 179,399. Of these,
134,707 were yellow (75.08796 percent) and
44,692 were green (24.91206). Mendel had
reported 75.05% vs 24.95%.
Fisher, R.A. (1936). Has Mendel's Work Been
Rediscovered? Annals of Science 1, 115-137.
11
孟德爾是修士、學過物理、數學、生物學
 In 1807, an imperial order demanded that the Augustinians at
St Thomas should take up the teaching of mathematics and
biblical studies in the newly established Philosophy Institute
and the Brno Theology College.
 Flood and other presumed catastrophes receded, first in the
face of Scottish geologist Charles Lyell's arguments begun in
the 1830s that the Earth had been shaped by gradual, ordinary
forces working over a vast timescale. They ebbed even further
with the coming of Darwinism in the 1860s (against the
biblical answer ).
12
 A link between the study of natural disciplines, such
as botany and zoology, and physics had already been
expressed by Andreas Baumgartner (1793-1865),
professor of Physics at the University of Vienna until
1864, who acted as examiner for Mendel in Brno in
1850. Baumgartner had been so impressed by Mendel,
that he suggested to Abbot Napp that the young monk
should be sent to the University of Vienna. Professor
Baumgartner emphasized the importance of studying
nature, not through random speculation but through
experiments theoretically underpinned by
mathematical models.
13
孟德爾的老師
Andreas Baumgartner (1793 - 1865)
 In 1823 he lectured at
Vienna university,
published his works as
well as a Magazine of
physics and
mathematics, and wrote
a book of elementary
physics.
 A native of Frymburk
in the Český Krumlov
region.
14
孟德爾的老師
 Franz Unger (1800-1870) : about
Evolution (1852, Wien), test how
variation is formed (How to do this?).
 Darwin published “On the origin of
species: in 1859
 1869, Mendel had talked about
evolution, and sent a copy of paper
to Darwin.
 Christian Doppler (1803-1853 ): on
physics.
15
16
17
http://www.gmi.oeaw.ac.at/institut2geschichte.htm
18
孟德爾還知道哪些事?

Atomic theory by John Dalton (17661844).
http://falcon.sbuniv.edu/~ggray.wh.bol/CHE1104/pcp3outl.html

可能知道 Statistic 嗎?
Father of epidemiology: John Snow: 1813-1859
19
Mendel's green pea (Pisum sativum), is also called the
garden pea or English pea.
20
http://ridge.icu.ac.jp/gen-ed/mendel-gifs/18-mendel-cartoon.JPG
http://www.brooklyn.cuny.edu/bc/ahp/MBG/MBG.Peas.html
• The monks in Mendel's
monastery would have
really appreciated his
crops as peas are best if
eaten almost
immediately. Like corn,
peas lose their sweet
flavor very rapidly.
21
A.
B.
A
List of seeds ordered by Mendel to Ernst Benary for the Abbey, 2nd
November 1878, and a bill from the seed firm, Bestell Nota Herrn
Ernst Benary in Erfurt.Brno, Abbey of St Thomas
Grafting and pruning tools in wooden box, Dittmar Keilbronn Brno,
Abbey of St Thomas
B
孟德爾用的工具吧
http://www.mendel-museum.org/eng/1online/room1.htm
22
不要與觀賞用的香豌豆混淆了
香豌豆 Lathyrus odoratus L.
• 別名：花豌豆、麝香豌豆、香豆花
• 一、二年生草本；莖有翅，被短柔毛，
柔軟多汁，高約150公分左右。葉為羽
狀複葉，寬橢圓形或長圓狀卵形，葉基
的一、二小葉先變為卷鬚，可捲繞它物
而向上生長；葉軸有翅，上部有3-5對
卷鬚。總狀花序有花1-5朵，蝶形花冠
有白、紅、粉紅、紫紅等多種顏色，具
香氣。莢果有短柔毛；種子多數，近球
形，熟時灰棕色。花果期4-9月。
• 有毒部位：種子和開花時期的莖、葉
有毒，以未成熟種子毒性最強。中毒病
狀：人中毒後往往出現一系列脊椎功能
障礙，開始時兩腿無力，然後腰痛逐漸
加重，行走困難，前進時足向內翻或貼
地。
23
Mendel‘s green pea (這不是一開始的說法)
D
D
R
R
Seed shape
Seed color
Flower position
Flower color
應該是子葉的顏色
Pot shape
Pot color
Stem high
http://ridge.icu.ac.jp/gen-ed/mendel-gifs/03-mendel-characters2.JPG
24
孟德爾用的七種豌豆特徵
1.
Shape of seed, whether rounded or irregularly angular and deeply
wrinkled.
2.
Colour of cotyledons [“ endosperm”], whether some shade of yellow
or green.
3.
Colour of seed-skin, whether a brownish shade or white (in correlation
with white flowers).
4.
Shape of ripe pod, whether simply inflated or deeply constricted
between the seeds.
5.
Colour of unripe pod, whether a shade of green or bright yellow.
6.
Position of flowers, whether distributed along the stem or crowded near
the top in a false umbel.
7.
Length of stem, whether about 6-7 feet or about 3/4 --> 1 and 1/2 feet.
Between these various pairs of varieties crosses were then made, the
female parent being emasculated.
http://post.queensu.ca/~forsdyke/bateson1.htm
25
http://www.mendelweb.org/MWGerText.html
德文版原文的記載
 Auf den Unterschied in der Gestalt der reifen Samen.
 Auf den Unterschied in der Färbung des Samen-Albumens
[Endosperms].
 Auf den Unterschied in der Färbung der Samenschale.
 Auf den Unterschied in der Form der reifen Hülse.
 Auf den Unterschied in der Farbe der unreifen Hülse.
 Auf den Unterschied in der Stellung der Blüthen.
 Auf den Unterschied in der Axenlänge.
26
For lecture only; BC Yang
http://www.giddings.txed.net/biology/ch12.html
就是這樣做
So ist es gemacht!
27
For lecture only; BC Yang
Mendelregeln
 1. Uniformitätsregel (顯隱律):
– Kreuzt man zwei Individuen einer Art, die sich nur in einem Merkmal
unterscheiden und in Bezug auf dasselbe homozygot sind, so sind die
Individuen der Tochtergeneration (F1) im betrachteten Merkmal gleich, d.h.
uniform. Alle Individuen der Tochtergeneration haben nicht nur denselben
Phänotypus, sondern auch denselben Genotypus. Dies trifft sowohl beim
intermediären als auch beim dominanten Erbgang zu.
 2. Spaltungsregel (分離律):
– Kreuzt man Individuen der F1- Generation unter sich weiter, so kommt es zu
einem Aufspalten der Merkmale. Vom Phänotypus findet das Aufspalten beim
intermediären Erbgang im Verhältnis 1:2:1 statt, beim dominanten im
Verhältnis 1:3. Der Genotypus tritt in beiden Erbgängen im Verhältnis 1:2:1
auf.
 3. Regel von der Unabhängigkeit der Erbanlagen (獨立分配律):
– Kreuzt man zwei Individuen einer Art, die sich in zwei Merkmalen
unterscheiden und in Bezug auf dieselben homozygot sind, so findet man in
der F2- Generation eine Aufspaltung der Merkmale im Verhältnis 9:3:3:1 beim
dominanten Erbgang. Dies beweist, dass die Gene unabhängig voneinander
vererbt werden und frei kombinierbar sind.
28

由種子商購買 34 個豌豆品種，培育兩年
成為純系。他發現有22 株系的性狀穩定，
然後又選定 7 種性狀作為觀察性狀在世代
間傳遞情況的指標.......

豌豆有七條染色體。

據說研究進行八年，對兩萬八千株植物進
行交配實驗。這八年孟德爾在想什麼 ?
在費曼之前 – 二十世紀的科學簡史; 陳恒安譯, 究竟, 台
北 (2002), p 70. 原始資料待查!
29
具象與抽象
As time goes by, the biological life goes down to
a sign of sign, a mix of molecules, and imaging
set of colors with colorless.
Mitosis in Onion Root Tips
Down to a microarray
30
For lecture only; BC Yang
在接受且理解孟德爾發現的必要條件有哪些?
 孟德爾以概念 (以 Elementet 稱呼他所追蹤的遺傳單
位)
和假設的理論掌握自然的規律(關係) 。
但是概念必須有實物相對應，才能展現
其存在的意義。
31
三個爭奪「重新」發現遺傳定律的故事
1. Hugo de Vries (1848-1935)
2. Carl Erich Correns (1864-1933)
3. Erich von Tschermak-Seysenegg (1871 -1962))
32
 When Mendel's paper was published, in 1866, it received little
attention, and was rarely cited by botanists or biologists during the
next 34 years. Mendel's work has been thought to exemplify
everything from the failure of traditional modes of scientific
communication (Bush [1945]) to the phenomenon of "premature
scientific discovery" ( Stent [1978]). In 1900, Mendel's work was
cited by three botanists, writing in different parts of Europe: Hugo
de Vries, in Amsterdam; Carl Correns, in Tübingen; and Eric
Von Tcshermak, in Esslingen, Austria. Although their
interpretations of what Mendel had shown were arguably
inaccurate, these citations caused what has come to be known as
the "rediscovery" of Mendel.
http://www.mendelweb.org/MWhartl.intro.html
33
It may be premised that the first publication of the rediscovery was made in 1900 by de Vries, {De Vries,
'Comptes Rendus,' March 26, 1900, and 'Ber. deut. Bot.
Ges.,' xviii, 1900, p. 83; ibid., p. 435; 'Rev. gen. Bot.,'
1900, p. 257.} and almost simultaneously by Correns
{Correns, 'Ber. deut. Bot. Ges.,' xviii, 1900, p. 158; 'Bot.
Ztg.,' 1900, p. 232.} and Tschermak {Tschermak, 'Ztschr.
f. d. landw. Versuchswesen in Oesterr.,' 1900, 3, p. 465}.
There can be no doubt that the appearance of this group
of papers constitutes at length a definite advance both in
the general study of the physiology of reproduction and in
the particular problem of the nature of Species.
http://post.queensu.ca/~forsdyke/bateson1.htm
34
Two stories
 A fellow Dutch scientist, Professor Beyerinck of Delft, knew that de
Vries had been hybridizing plants and wrote asking if he would be
interested in an old reprint dealing with the same subject. It was Mendel’s
“Versuche über Pflanzen Hybriden”, which reached de Vries in 1990, just
as he was preparing to publish his own experiments.
 In the autumn of 1899 the solution came to Correns in a “blind flash”,
which seems to be the origin of the truly important breakthroughs in
science. A short time later he found a reference to Mendel’s paper and
looked it up. He published his own data and showed how it confirmed
what Mendel had found.
Summary by Moore JA, 1993, in: Science as a way of Knowing,
The foundations of modern biology. p286
Moore 也把 Eric Von Tcshermak 的貢獻忽略了!
35
 Vries, Hugo de. "Das Spaltungsgesetz
der Bastarde," Berichte der deutschen
botanischen Gesellschaft 18 (1900), pp.
83-90. An English translation by
Evelyn Stern, "The Law of
Segregation of Hybrids", appears in
Stern and Sherwood (1966), pp. 107117.
 Stern, Curt and Eva R. Sherwood ed.
The Origin of Genetics: A Mendel
Source Book. (W.H. Freeman and
Company, 1966).
Hugo de Vries
1848-1935
36
 De Vries { C. R., 1900, March 26; 'Ber. deut. Bot.
Ges.,' 18, 1900, p. 83.} working with pairs of
varieties belonging to a diversity of genera and
species, found that in a large number of cases one
of the varietal characters was definitely dominant,
prevailing in the first crosses to the exclusion of the
recessive character.
罌粟
 The offspring of the cross-breds fertilised inter se
were mixed dominants and recessives in
proportions fairly agreeing with Mendel's law.
 In the case of two colour varieties of Papaver
somniferum, the constitution of the resulting
dominants was investigated, and shown to be also
according to the law. In certain cases also the purity
of the recessives was tested and found to be
complete.
Papaver somniferum
http://post.queensu.ca/~forsdyke/bateson1.htm
37
在 Amsterdam 的旅館
Park Hotel "Hugo de Vries" is gehuisvest in een sinds
1904 bestaand statig Herenhuis, welke in opdracht van
professor Hugo de Vries is gebouwd en vervolgens
bewoond. Deze professor was plantkundige en leraar
aan de Hortus Botanicus in Amsterdam en heeft
destijds veel betekend voor de ontwikkeling van het
enten en kruisen van planten en bloemen
http://www.senotel.nl/hugodevries.html
38
Carl Erich Correns (1864-1933)
 Im Botanischen Garten von Tübingen, wo
Leonhart Fuchs (1501-1566) im 16. Jahrhundert
bereits einen Hortus Medicus aufgebaut hatte,
begann Carl Correns 1894 seine
Vererbungsexperimente, welche 1900 zur
Wiederentdeckung der Mendelschen
Vererbungsregeln beitrugen.
 Correns erkannte durch seine Experimente aber
auch, dass nicht alle Merkmale frei miteinander
kombinierbar seien, sondern dass einige
eindeutig untereinander gekoppelt sind (d.h. stets
gemeinsam vererbt werden).
聯鎖遺傳?
http://home.tiscalinet.ch/biografien/biografien/mendel.htm
39
Some references
 Correns, Carl. "G. Mendel's Regel über das Verhalten der
Nachkommenschaft der Rassenbastarde," Berichte der
deutschen botanischen Gesellschaft 18 (1900), pp. 158-168.
An English translation by Leonie Kellen Piternick, "G.
Mendel's Law Concerning the Behavior of Progeny of
Varietal Hybrids," appears in Genetics [1950], pp. 33-41, and
Stern and Sherwood (1966), pp. 119-132.
 Genetics. The Birth of Genetics: Mendel, de Vries, Correns
and Tschermak in English Translation. Supplement to
Genetics 35, September 1950, No. 5 pt. 2.
http://www.modares.ac.ir/elearning/mnaderi/Genetic%20Engineering%20course%20II/
Pages/history_of_genetics3.htm
40
Correns C 用的材料
Matthiola incana 紫羅蘭
Correns 待過的植物園
我曾經在Tübingen
41
 Correns {'Bot. Cblt.,' 1900, 43, p. 97} has appeared
describing his experiments with a glabrous [without
hairs] and a hoary form of garden stock (Matthiola
incana), and giving results as to these varieties,
tested by self-fertilization, and also by recrossing the
cross-breeds with them parental forms. The facts
taken together are in fairly close agreement with the
expectation given by Mendel's law, though the
discrepancies are decidedly greater in this case than
in the others.
 Lastly, Professor Correns has also published
{'Biblioth. Bot.,' 1901, Heft 53} an elaborate and
important memoir on the results obtained in crossing
varieties of maize.
http://post.queensu.ca/~forsdyke/bateson1.htm
42
也是八年
Nägeli 做這個
 Correns was a tutor at the University of Tübingen
when he began to experiment with trait inheritance
in plants in 1892. Correns already knew about
some of Mendel's hawkweed plant experiments
from Nägeli. Nägeli, however, never talked about
Mendel's key pea plant results, so Correns was
initially unaware of Mendel's laws of heredity.
 However, by 1900, when Correns submitted his
own results for publication, the paper was called: G.
Mendel's Law Concerning the Behavior of the
Progeny of Racial Hybrids.
 Correns and de Vries were the ones who most
clearly "redefined" Mendel's laws. Correns (with
credit to de Vries) restated Mendel's results, giving
us Mendel's law of segregation and Mendel's law
of independent assortment.
Karl Wilhelm von
Nägeli (1817-1891)
Eric von Tcshermak 的貢獻被忽略了!
43
Erich von Tschermak-Seysenegg

Because he was younger, and not as established
in the scientific community, Tschermak was
worried about the acceptance of his paper given
those of de Vries' and Correns'. However, he was
able to rush his paper to press, and was accorded
his share of attention as one of the rediscoverers
of Mendel's laws.

Tschermak was a plant breeder, and his
hybridization experiments were done with the
idea of improving crops using the laws of
heredity. He did most of the work himself, and
produced high-yielding food crops such as wheat,
barley, and oats. In 1903, Tschermak was
appointed associate professor at the University of
Agricultural Sciences in Vienna, and later
became a full professor. He was a major
influence in agriculture and plant breeding in
Austria.
http://www.modares.ac.ir/elearning/mnaderi/Genetic%20Engineering%20course%20II/Pages/history_of_genetics3.htm
44
 Tschermak worked with many varieties of peas, and
though he obtained several results not wholly consistent
with Mendel's law, and some actually conflicting
evidence, the general tenour of his work is confirmatory.
He gives, in particular, results as to the crossing of crossbreds with one or other of the pure forms.
 Tschermak's numbers though insufficient for a thorough
test, are in fair harmony with Mendel's hypothesis. He
believes also that there is evidence that yellow is more
decidedly dominant over green, than the rounded
character is over the wrinkled, and on this point further
experiments are required.
45
孟德爾以概念 (以 Elementet 稱呼他所追蹤的遺傳單位) 和假設的理論掌握自然的
規律(關係) 。但是概念必須有實物相對應，才能展現其存在的意義。
 1866, Mendel published his lecture, a work that was








to establish him as “the father of genetics”.
1869 Johann Friedrich Miescher (nuclein)
1873 Anton Schneider (meiosis)
1879 Walther Flemming (chromaton, mitosis)
1888 Wilhelm von Waldeyer-Hartz, (term
chromosome)
1902 Walter Stanborough Sutton. (chromosomes
carry the units of inheritance)
1904 Theodor Boveri (correlation between Mendel's
factors and chromosomes )
1904 William Bateson (genetics)
1909 Wilhelm Johannasen (gene)
46
DNA to chromosome to DNA
 1869 Johann Friedrich Miescher identifies a weakly acidic
substance of unknown function in the nuclei of human white blood
cells. This substance will later be called deoxyribonucleic acid, or
DNA.
 1924 Microscope studies using stains for DNA and protein show
that both substances are present in chromosomes.
 1928 Franklin Griffith, a British medical officer, discovers that
genetic information can be transferred from heat-killed bacteria
cells to live ones. This phenomenon, called transformation,
provides the first evidence that the genetic material is a heat-stable
chemical.
 1944 Oswald Avery, Maclyn McCarty, and Colin MacLeod,
identify Griffith's transforming agent as DNA.
http://www.csuchico.edu/anth/CASP/Carmosino_P.html
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
It was while working on pus cells at Tübingen in 1869 that
Miescher made his fundamental discovery. It was thought that
such cells were made largely of protein, but Miescher noted the
presence of something that "cannot belong among any of the
protein substances known hitherto."

He showed that the new substance was derived from the nucleus of
the cell alone and consequently named it 'nuclein'.

Miescher was soon able to show that nuclein could be obtained
from many other cells and was unusual in containing phosphorus
in addition to the usual ingredients of organic molecules - carbon,
oxygen, nitrogen, and hydrogen. It was not until 1871 that
Miescher, Johann Friedrich II
1844-1895
Miescher's paper, delayed by Hoppe-Seyler (who wanted to
Switzerlander
confirm the results), was published.
http://www.laskerfoundation.org/news/gnn/timeline/1869a.html
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1873 and after
 The discovery of chromosomes cannot be
pinpointed to a single person. It was a
consequence of the growing interest in the
division processes of the fertilized egg.
 Scientists on cell division : Anton Schneider,
Eduard Strasburger, Otto Bütschli, Edouard van
Beneden, Leopold Auerbach, Hermann Fol,
Walther Flemming.
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Walther Flemming 1843 - 1905
 1879: he described and named
"chromaton", "mitosis" and
"spireme", made the first accurate
counts of chromosome numbers and
figured the longitudinal splitting of
chromosomes.
http://www.nature.com/cgitaf/DynaPage.taf?file=/nrm/journal/v2/n1/full/nrm0101_072a_r.html
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 Flemming observed for the first
time that the chromosomes during
cell division became split along
their longitudinal axis, now
known to consist of chromatids,
and in 1880 he formulated the
sentence: "Omnis nucleus e
nucleo".
 All nuclei come from nuclei
(1863), omnis cellula e cellula
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Walter Stanborough Sutton.
 He was the U.S. geneticist (and also surgeon)
who provided the first conclusive evidence
that chromosomes carry the units of
inheritance and occur in distinct pairs.
 The two papers (Sutton, 1902, 1903) written
as a graduate student under E. B. Wilson at
Columbia University formulated the concept
that chromosomes carried the units of
heredity and explained Mendel's laws.
1877-1916
http://www.kumc.edu/research/medicine/anatomy/sutton/surgical_career.html
http://post.queensu.ca/~forsdyke/guyer.htm#Chromosomes%20in%20Heredity
52
I believe this creature is what Sutton has
seen during his study at Columbia
University
(BC, 2004)
 While he was working as a graduate
student at Columbia University,
studying grasshopper cells, Sutton
observed that chromosomes occurred
in distinct pairs, and that during
meiosis, the chromosome pairs split,
and each chromosome goes to its own
cell. Sutton announced this discovery
in his 1902 paper On the Morphology
of the Chromosome Group in
Brachyotola.
http://www.kumc.edu/research/medicine/anatomy/sutton/surgical_career.html
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Theodor Boveri (1862-1915)
 He saw that as egg cells matured, there comes a
point where chromosome numbers are reduced in
half. Boveri was one of the first to see evidence of
the process of meiosis. (In the late 1880's and
early 1890's)
 When Mendel's laws were rediscovered in 1900,
Boveri recognized the correlation between
Mendel's factors and the cytology work being done
on chromosomes (1904?).
Some one had already improved the staining technique for chromosomes
http://www.dnaftb.org/dnaftb/concept_8/con8bio.html
54
William Bateson (1861-1926)
William Bateson describes gene linkage, showing that more than one
gene may be required for a particular characteristic or trait (1904).
A hereditary factor like, for example, the shape of the seed, the colour
of the cotyledons or the colour of the seed shell shall be called a gene
(following a suggestion of BATESON made in 1905).
http://post.queensu.ca/~forsdyke/bateson1.htm
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Wilhelm Johannasen (1857-1927)
 Danish botanist Wilhelm Johannsen coined the word gene
(1909) to describe the Mendelian units of heredity.
 He also made the distinction between the outward
appearance of an individual (phenotype) and its genetic
traits (genotype).
 The proposed word traced from the Greek word genos,
meaning "birth". The word spawned others, like genome.
http://www.genome.gov/Pages/Education/Kit/main.cfm?pageid=24
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http://www.dnaftb.org/dnaftb/concept_5/con5gallery.html
First page of a 1905 letter written by William Bateson, first Director of the John
Innes Institute, to Adam Sedgewick, Cambridge professor. Bateson coined the term
"genetics" in this letter. he felt the need for a new term to describe the study of
heredity and inherited variations. But the term didn’t start spreading until Wilhelm
Johannsen suggested that the Mendelian factors of inheritance be called genes.
57