SciRev. X102 Exam 3 wk. 10 Natural History examwith 100% correct answers

reflections on disciplines

-in all areas of knowledge there were profound transformations across history

-areas of knowledge or disciplines are not eternal and unchanging, but have their own history

-biology as a discipline didn't always exist

-natural history studied nature

biology

-was coined in the 18th century but became common in the 19th century

natural history

-studied nature

-including both living and non-living parts

-ex. animals, plants, and minerals

-study was nature, not biology (no biology departments)

aristotle's soul

-the mortal form of a living organism

-the soul was key to understanding animals and plants

descartes' soul

-disagreed w/ aristotle's soul

-only humans had a rational (immortal) soul

-all operations of the body occurred mechanically

-animals and plants were complex machines

mechanism

meaning that all operations of the body occur following physical laws which make no distinction btw living and non-living

vegetable staticks

-stephen hales

-reported several physical experiments on plants involving perspiration and pressure

Julien Offray de la Mettrie

-was the most extreme mechanist

-published Man Machine

-views were considered unacceptable in Christian europe

-died of indegestion in Berlin

man machine

-mettrie

-claimed that not only animals but also humans were just machines

difficulties w/ mechanism

-generation

-vitalism

-life functions

generation

-many experiments on many types of plants established their sexual reproduction

-this result was suggested by the analogy of snails, bc plants and snails were hermaphroditic

-epigenesis

-preformation

hermaphroditic

Possessing both the male and the female reproductive organs

vitalism

-opposing view to mechanism

-there are key differences btw living and non-living organisms

-differences could be due to a soul or based on the idea that special laws/forces applied to life

sensibility

-some argued that mechanical and chemical forces couldn't explain life functions

-a special force

-was proper to all living matter

epigenesis

-term coined by william harvey

-means that the embryo originated from a homogeneous mass by successive differentiation

performation

-means that the embryo is already formed and merely grows

-Swammerdam

Jan Swammerdam

-explained preformation

-argued that all living beings were initially created by God and were all encased one inside the other, like russian dolls

-thus explaining why original sin was carried over to all subsequent generations

-easier to explain than the formation of an entirely new organism

those who believed in the uniformity in nature were...

stunned by two discoveries that highlighted its variability: female aphids could reproduced by parthenogenesis and a hydra cut in half grows back the missing part

charles bonnet

-observed that female aphids could reproduce by parthenogenesis

-"virgin generation"

-namely w/out males

Abraham Trembley

-showed that by cutting in half in any directiona hydra or fresh water polyp, each half could regenerate the missing part

-could also turn a hydra inside out like a glove w/out negative effects

Trembley's experiment

-used a magnifying lens close to the jar w/ the hydra or polyp

-tiny organism is viewed

Lazzaro Spallanzani

-a catholic priest and naturalist

-carried out many experiments on generation

-many were used on frogs (a useful 'model organism') bc they have external insemination so he could see what was going on

-tried to figure out how fertilization occurs (possibly thinking it worked like a magnet)

-put eggs and sperm very close to each other to see whether fertilization would occur, showed contact was essential.

-frog w/ pants experiment

Spallanzani's frog experiment

-put tight-fitting pants on male frogs

-this prevented their semen from getting in contact w/ the eggs

-if it worked like a magnet, fertilization would occur

-if it was direct contact, fertilization wouldn't occur

-no fertilization occurred

-proving direct contact was essential

artificial insemination

-experiment by spallanzani

-artificially inseminated frogs by spreading sperm on the eggs

-proved the key role of sperm in generation

John Turbeville Needham

-boiled broth

-challenged by Spallanzani

boiled broth idea

-needham

-tiny organisms spontaneously emerged in boiled broth

-used a cork to seal the vessel

Spallanzani on boiled broth

-denied spontaneous generation

-showed that boiled broth in a sealed container remained sterile

-needham only corked (not sealed) the vessels which has poroes that allow air in w/ micro-organisms

taxonomy

classification of plants and animals

problem of taxonomy

-Did it reflect a natural order or was merely a matter of convenience?

-was it based on one key character only, or many?

carl linnaeus

-relied on the finding of the sexual reproduction of plants

-argued for only one character, fructification structures

-tried to formulate a system that captured the real features of plants (and animals) that God had estabished at creation

Michel Adanson

-argued that to rely on one character only was insufficient and arbitrary

-favored a system based on all characters

herbaria

-established as a tool for preserving and studying plants by Luca Ghini

-became indespensable tools for botanists, especially those engaged in taxonomy

Linnaeus's herbarium

-first w/ loose sheets, not bound in bolumes

-enabled him to move specimens as his classifictaion scheme evolved

systema naturae

-linnaeus

-used his binomial system to classify plants into 24 classes

-relied on his herbarium

-also classified animals and minerals

Georges-Louis Leclerc, Comte de Buffon

-author of histoire naturelle

-very different views

-argued that any classification system was purely arbitrary and based on convenience

-there were no genera, order, and classes in nature, only individual specimens

-denied that we can know the essence of things

-argued that the Linnaean system was precise bc it was abstract and artificial

-denied that you can group things together