task 4 Flashcards
Charles Darwin
–> evolution theory
- 1809-1882
ZEITGEIST
- theory was bound to be discovered around mid-19th century
CROSS-FERTILISATION
- used by many plants rather > more variation
- -> more vital
- -> resulted in new type of flower
NATURAL SELECTION
- envrionment results in
–> continuation & mulitplication of organisms with “favourable features”
–> hindering reproduction of organisms with “unfavourable features”
» “Survival of the fittest”(Spencer)
- impact of theory became clear when biologists understood nature of inheritance
- -> genes are mixed in progress of conception
evolution theory
–> DILUTION PROBLEM
- Darwin failed to explain how single organism could come to dominate the rest
JENKIN’S DILUTION PROBLEM
- when organism with new feature is placed amid group
- -> new feature will not expand but dilute in pool of preexisting features
> Darwin’s response:
- evolution is only possible when change in evnironment favoures a whole group at the same time
misunderstandings of evolution theory
- NO DIRECTION IN GENETIC CHANGES
- genetic material has RANDOM ALTERATIONS - ORGANISMS DO NOT BECOME BETTER/STRONGER
- depends on environment what species survives/extincts
- -> e.g. nowadays there are more dogs than wolves
Francis Galton
- 1822-1911
- influenced by Darwin
- suggested that mental qualities are inherited
- measured human intelligence
–> by measuring various aspects of men
» wasn’t really successful but INSPIRED subsequent generations to ADDRESS ISSUE OF INTELLIGENCE TESTING
factors that influenced Darwin (3)
- Paley’s argument:
- -> adaptation of living beings to their surrounding was so perfect that it proved the existence of god” - Voyage on Beagle from Henslow
- Lyell’s “Principles of Geology”
factors that influenced Darwin
|»_space; PALEY’S ARGUMENT
“adaptation of living beings to their surrounding was so perfect that it proved the existence of god”
- Darwin was against “perfect design”
- -> investigations of animals/plants adaptations to provide alternative
- kept alive sense of wonder that he learned by Palvey
factors that influenced Darwin
|»_space; VOYAGE WITH HENSLOW
- determined his whole career
- made extensive observations on habit, behaviour, distribution
THREE FINDINGS WERE STARTING POINT FOR HIS VIEWA
- fossils in patagonia
- animals were built on same anatomical plan as current inhabtiants
- -> CONTINUITY OF TYPE - geographical distribution patterns of south american ostrich
- smaller than northern form
- -> closely related species are MUTUALLY EXCLUSIVE - animal life of galapagos islands
- DIVERSITY OF SAME SPECIES
- also met diversity of populations
- -> all brothers under skin
- -> could be civilised but reverted afterwards to their aboriginal state
factors that influenced Darwin
|»_space; LYELL’S “PRINCIPLES OF GEOLOGY”
- principles claimed
–> earth surface shows no evidence to be built by god
–> it constantly experiences accumulative changes
» no god-given direction -> UNIFORMITARISM - principles put Lyell in dilemma
- -> geological gradualism = biological gradualism
- Lyell attacked Lamarck to defend his point of view
- Darwin used this information
- -> adopted Lyell’s belief of gradual change
gradualism
variation is gradual in nature and happens over time as opposed to in large steps
Darwin’s letters
- his success depended on others
- -> letters with Alfred Wallace (travelling naturalist/similar ideas to Darwin)
intelligent design
- states:
- -> some powerful designer suspended normal function of things to assemble it
2 components:
> IRREDUCIBLE COMPLEXITY:
- functions are assigned to structures
–> could not have evolved by nature
CRITIC: structures can gain second function
> SPECIFIED COMPLEXITY:
- probability theory: chances are too low that structure evolved by natural processes/chance > specially designed
CRITIC: we cannot assign probabilities for such events
- some ID proponents want to REMOVE NATURSLISM
modern synthesis
- fusion of Mendelian genetics with Darwin’s theory
|»_space; evolution theory
Darwin: altruism <> group selection
- “morally weaker”/poorer people > more offspring > regression of evolution
- altruistic/morally stronger groups would survive & develop better
–> worst characteristic traits eliminate themselves (insane > institutions // criminals > prison) - no natural selection in society > negative development
» Hamilton: inclusive fitness theory - solution:
- moral qualities could get more advanced by habit/reason/learning/religion
- being wealthy necessary for evolution
- -> necessary for advancement of morality
altruism vs. survival of the fittest:
> group of weak individuals vs. the strong individual
controlled reproduction
- “eugenics”
- became popular with turn of century (19th)
- POSITIVE EUGENICS: aimed to increase desirable traits
- NEGATIVE EUGENIC: aimed to decrease undesirable traits
- enthusiastic following > seemed like common-sense to control breeding
- interventions:
- -> USA (1924): immigration restriction act > seen as inferior
- -> Germany (1933): Hitler
- —> some Darwinits separated themselves: racist direction
principle of inheritance
- by Lamarck
- hypothesis: organisms can pass on characteristics that it has acquired through use or disuse during its lifetime to its offspring
