HOW the areas of study provide evidence for the theory of evolution (1 Viewer)

[meLoncoLLie]

describe, using specific examples, how the theory of evolution is supported by the following areas of study:
- palaeontology, including transitional forms
- biogeography
- comparative embryology
- comparative anatomy
- biochemistry


okay i have no trouble in describing these areas of study and giving examples, however i find it difficult to link them back to the theory of evolution - HOW do they support it? take palaeontology for instance, is it just as simple as say, 'the fossil record of horses show a gradual change in the characteristics of the species, therefore the species must have evolved...'

any help will be appreciated! (come on xiaoie you're usually good at this )

 

[Survivor39]

It's simple. Take transitional form the archeopteryx, it resembles half bird and half reptile, this suggest that bird may have evovled from reptilian, a gradual change is evident.

Another example, embrology. Hiuman embryo and chicken, frog embryoes share remarkable similarities at an early stage, e.g. notochord, tail, gill slits. These evidence suggest that these organisms may have evolved from a common ancestor.

Same for all of the other points.

 

[meLoncoLLie]

You must spread some Reputation around before giving it to Survivor39 again.

oh, and biogeography is really confusing. so they've come to the conclusion that species living in a particular region will be more closely related to fossil species of that region than to species living in a distant region with similar conditions. and also, a particular species tends to be distributed in a certain area only (if they haven't been introduced artificially to another area).

by looking at the former, we know that species evolve. but what has it got to do with the geographic distribution of the organisms?

 

[Abtari]

yes, i am having the same trouble, ESPECIALLY with biogeography and comparative embryology. just because they all have gill slits or a tail when they are young (or just because they all look alike at that stage), how does that support evolution? and as for biogeography, i'm stumped.

 

[Survivor39]

Ok for biogeography, take the wattle for example. Some are found in the Australian east coat, and some in South America and some scatter in the Asia pacific. Evidence show that Australia and South America were once connected (to form Gondwana). Once the two continent were separated, the wattle evolve into their own distinct ways. Now if you compare the two from the two places, they have very similar characteristics but are different species. This suggest and therefore, support, evolution has taken place as time progresses.

 

[Survivor39]

yes, i am having the same trouble, ESPECIALLY with biogeography and comparative embryology. just because they all have gill slits or a tail when they are young (or just because they all look alike at that stage), how does that support evolution? and as for biogeography, i'm stumped.

My previous post:
Human embryo, chicken and frog embryoes share remarkable similarities at an early stage, e.g. notochord, tail, gill slits. These evidence suggest that these organisms may have evolved from a common ancestor.

Because they have once evolved from the same organism, there has to be some commonaility between the three organisms above, right? How can we see these similarities? You look at the early development of their embryoes. They look all similar. Even embryologists cannot tell which embryoes will be developed into which organisms in the early weeks of development. Therefore, this support that evolution occurs, from a single common ancestor, to evolved into a human, a frog and a chicken (or whatever you wish to compare with).

 

[malkin86]

It supports evolution because they all look the same when they're embryonic - therefore not much is different between the embryonic fish and embryonic human - therefore common ancestry.

Biogeography: the geography of a region can influence the selection criteria for the organisms living there - eg. rainforest plants (broad leaves for sunshine, direction of water to roots) and desert plants (spines rather than leaves for waterloss).

 

[Abtari]

but i thought ontogeny doesn't recapitulate phylogeny..

i.e. the development of an individual (ontogeny) does not retrace the stages through which the INDIVIDUAL SPECIES has passed during its evolution (phylogeny)

so how can we say, "yes, hence they must have shared a common ancestor"

i thought that embryological development of an individual had nothing to do with evolutionary development of a species.

 

[kami]

but i thought ontogeny doesn't recapitulate phylogeny..

i.e. the development of an individual (ontogeny) does not retrace the stages through which the INDIVIDUAL SPECIES has passed during its evolution (phylogeny)

so how can we say, "yes, hence they must have shared a common ancestor"

i thought that embryological development of an individual had nothing to do with evolutionary development of a species.

It's more than that - for example every chicken, chimp and dolphin would have gills while at a certain stage in embryonic development, this shows that it is *likely*(not definitive) that they shared a common point oof ancestry as they have a common feature.

 

[Abtari]

ah i see... likely...

 

[kim_]

comparative anatomy-some organisms have similar anatomy or structures which can be seen as evidence of evolution from a common ancestor.
palaentology-the study of fossils. fossils sho how species have changed gradually over time...the evidence of how species has evolved
biogeography-study of geographical distribution of organisms(6 major biogeographical zone) zoes are seperated by physical barriers. barriers seperate populations of organisms in different regions, preventing them from interbreeding htis may produce new species if popultaions evolce independently and do not share a common gene pool., because australia seperated from asia before placental mammals evolved, aust mammals thrived in isolation while those in asia had been outcompeted by placental mammals and become extinct... new species evolve from old species...supporting darwins theory.
biochemistry-organusms that have same basic chemistry are used to determine evolutionary relationships

 

[jesster88]

oh, and biogeography is really confusing. so they've come to the conclusion that species living in a particular region will be more closely related to fossil species of that region than to species living in a distant region with similar conditions. and also, a particular species tends to be distributed in a certain area only (if they haven't been introduced artificially to another area).

by looking at the former, we know that species evolve. but what has it got to do with the geographic distribution of the organisms?

Ok heres how this works

Look at australia and papua new guniea they have similar land animals and marsupials - this is because at some stage in the earths geological history these 2 countries/islands etc were connected by land bridges etc...

This is also common of similar plant species found in australia and south america both were connected as a part of one of the two mega continents.

Other examples include the horses on frasier island - they had been there for maybe a century and the australian land conservation people decided to move them back to the main land as they were destructive to the sand island ecosystem ... anyways when they got back to the main land they all went lame because their hoofs had become soft and padded - addapeted to the soft sand of their environment.

A final example are the snakes on flinders island - these snakes have adapted to the environment by producing a venom 10 times more venomous/potent than the same species on the main land - this was so that the snakes could feed on birds who are a natural preditor of snake ... this comes from the isolation of the island and the lack of food choiced for the snake

hope this clears it up