Samenvatting
Summary History of Biology - Lecture 5
- Instelling
- Radboud Universiteit Nijmegen (RU)
History of Biology - Lecture 5
[Meer zien]Voorbeeld 2 van de 5 pagina's
Voorbeeld 2 van de 5 pagina's
In winkelwagengesponsord bericht van onze partner
Voorbeeld van de inhoud
History of Biology – Lecture 5: From generation to genetics07-03-18
End of 19th c. The problem of generation:
Generation was a broad problem in biology that consisted of:
- How does an embryo come to be and how does it grow?
- What is passed down during every cell division?
- How do organisms inherit characteristics?
- What is the relation between heritage and evolution? generation was much
more than just genetics.
In contrast, after 1920: ‘genetics’.
19th c. ideas about heredity: Darwin
Darwin’s speculative pangenesis theory; all cells have ‘gemmules’ which are
somehow mixed when passed down to offspring
Obvious objections:
- Why do blood transfusions not change heredity?
- That means that variations are mixed and diluted, so how can variations ever
stabilize?
Germ plasm theory by August Weismann: germ plasm (gamete) is different from
somatic cell.
Only germ plasm is capable of passing down characteristics, independent of what
happens to the somatic cell.
Gregor Mendel (1822-1884):
Augustinian monk, son of a farmer, became the abbot of a monastery in Brno, Czech
Republic.
The monastery was a local center for science and agricultural knowledge.
Mendel studied physics, theology, agriculture, among others.
Became a teacher, meteorologist (to support agriculture).
- Crossed bees and plants which led to Mendel’s laws (kruisschemas)
o Most famous experiment: crossing of peas.
Few problems:
- Debate whether Mendel was the first discoverer.
- Debate whether Mendel understood his own laws.
o Did he understand that there were 2 alleles?
Priority: who discovered it first?
The story of Mendel, again illustrates the importance of priority: be the first to claim
your discovery.
Recognition is an important reward, which often leads to priority conflicts.
Other examples:
- Watson + Crick
, - Darwin + Wallace
- Newton + Hooke
- Pasteur + Koch
Do mutations occur in leaps, or gradual, small steps?:
Ca. 1900, big discussion in heredity saltationism vs. gradualism:
- Saltationism: saltatio means ‘jump’ large amounts of mutations, which
occur very quickly (even in one single generation).
- Gradualism: mutations occur gradually, not very quickly/dramatic
(comparable to uniformitarianism vs. catastrophism – geology, lecture 3).
Thomas Hunt Morgan (1866-1945):
American biologist. Southern aristocrat, from an impoverished family after the
American Civil War.
Studied zoology and initially specialized in marine biology.
In the zoological laboratory of Naples, he came into contact with experimental
embryology.
At Naples, embryologists often worked with marine species.
Studied biological problems on embryology in Naples which was the key question at
the time.
In 1904, Morgan became professor of experimental zoology at the Colombia
University in New York. There he got interested in inheritance, mutations, Mendel
and evolution.
A convenient organism for studying these questions, was Drosophila melanogaster,
which was then already used by other biologists.
Morgan tried creating mutations by radiation, in order to find and test Mendel’s
patterns.
The fruit fly (Drosophila melanogaster) as an industry:
Drosophila became one of the most popular model organisms:
- Simple and easy to grow
- Clear research questions, rapid publication, large research output
- Linked with theoretically relevant questions of genetics to guide the research.
o Morgan’s research (mapping the genes of Drosophila) was seen as
‘normal science’.
Morgan is considered ‘The founding father of Genetics’.
Orthodoxy (juiste leer) occurs, through:
- Production of research
- Organization
- Identity
- Important applications
- Finance
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper rishology. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €3,99. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 70055 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen