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Science Natural Selection And Evolution! (1 Viewer)

broly_29

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Joined
Jan 9, 2006
Messages
57
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Male
HSC
2008
Can i plz have some notes to
1) Charles Darwin and evolution
2) The origin of species
3) Galapagos Islands - finches
4) Natural Selection
5) Artificial selection
6) Darwin's and Lanmark's theory (similarities and differences)
7) Divergent Evolution
8) Parallel evolution
9) Convergent evolution
10) Evidence of evolution (fossil evidence, comparative anatomy, comparative embryology, biography, DNA evidence)
11) How rocks tell a story ?
e.g telling geological time, southern hemisphre coal, plate tectonics, continents in collision, human impact on evolution

thanx
 

*wbg*

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Nov 14, 2005
Messages
57
Gender
Female
HSC
2008
first off broly dude its a bit weird to ask for a list of notes.. we are students too not note-churning machines and although this is a place where you can get HELP its not really a place where people will just do your work for you....(and i notice that you have asked for notes before.. its a good time to start making ur own and use bos as a supplement)

but since i have an exam on some of the stuff you listed im gonna try and answer tehm for my own revision :)

1) Charles Darwin and evolution
.... read on my friend

2) The origin of species
Speciation occured by natural selection over long periods of time combined with isolation and mutations. Geographical isolation means that the same organism in two different environments would allow mutations and natural selection to form towo SUBspecies. If this separation goes on for long enough and the two sets of animals are incapable of interbreeding reproductive isolation occurs producing two separate species.

3) Galapagos Islands - finches
these are isolated so illustrate the idea that many new species/forms can evolve from teh same ancestor. Divergent evolution indicates adaptive radiation where teh COMMON ancestral organisms adapts in its DIFFERENT envirnoemnt to form DIFFEReNT animals (e.g. shrew into the bear, bear, bat, squirrel...) Darwin found 14 finches with ismilar colours, nests, eggs etc, but differnet havitat, diet, size, beak shape -darwin explained this by them ahving a commmon ancestor but natural selection had created the differences. he thught that hte finches had probably come from different places where differentbeak shapes / diets etc were necessary for survival and had later migrated to the islands.

4) Natural Selection
natural selection is the concept of " survival of the fittest phenotype" were too many organisms are produced in teh first place. Organisms which by random chance have genetic characteristics most suited to an environment are more likely to survive and are thus morelikely to have offspring. A larger percentage of these offspring will be endowered with teh favourable characteristic which will make a bigger percentage of this second generation survive and have offspring (the others dying off.)E.g. many giraffs or different length necks, the longestones could reach teh food so the shorest ones died. thus the longest ones reproduced produceing more long necked giraffs (sp)

5) Artificial selection
When scientist select a particular characteristic of an organism that they like and mixonly organisms of this genetic make up to create offspring which have teh favourable characteristic that was selected. E.g. rust resistant wheat was created by selecting a strand of wheat that had that characteristic and reproducing only that strand.

6) Darwin's and Lanmark's theory (similarities and differences)
Darwin's theory of natural selection is outlined above. Lanmark's theory was that organisms adapt over generations to an environment (but not genetically) and although it is true taht this form of adaptation occurs it only occurs WITHIN the generation it cannot be passed down. They are called aquired characteristics and cannot be inherited. For example he thoguht that originally all giraffs (sp) were short and teh nicest leaves were at teh top of trees so in order to reach them over time the giraffs stretched thir necks and this stretched neck gene was inherited.

7) Divergent Evolution
Divergent evolution indicates adaptive radiation where teh COMMON ancestral organisms adapts in its DIFFERENT envirnoemnt to form DIFFEReNT animals (e.g. shrew into the bear, bear, bat, squirrel...)

8) Parallel evolution
realated secies evolve similar features whilst separated - look alike adn have a common ancestor but are in differnt locations.

9) Convergent evolution
occurs when organims evolve and end up having siilar strucures despite their different origins this can be due to living in similar conditions adn having siilar habits and lifestyles. thus the same cahracteristics are 'selected" for survival. They ahve analogous structures - look teh same but come from different ancesetors.

10) Evidence of evolution (fossil evidence, comparative anatomy, comparative embryology, biography, DNA evidence)
- Paleontology Identification of Fossils
Fossils are any part or impressio nfo a plant or animal that may survive after its death, tehy are fomred in sedimentary rock adn thus when unearthed are arranged in a chronological order from oldest at the bottem to youngest at the top. This provides insite into evolution because it demonstrates any structural adapations that may have evolved and it demonstrates differences in structural adaptions between organisms in different isolated areas (liek islands)
- embryology:
similarities in teh embryotic developemtn of organisms suggest that they all stemmed form teh same origin
- compariative anatomy:
the structures in different organisms can be shown to be similar (adapted slightly to their own environment0 which again suggests a common ancestor
- biogeography:
geographical distribution can suggest where species originally occured
- biochemistry:
similarities and differences in teh biochemical makeup of an organism parallel similaries and differences in appearances.
- molecular biology:
dna and protein sequences indicate dgrees of relatedness between organisms.
11) How rocks tell a story ?
clearly this is about the fossils being deposited in layers demonstratig chronological age discussed above.
 

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