analogous structure?

[joonkimdds]

This is how I studied for homologous and analogous structures.

Homologous = same structure but diff function
ex> wings of bat, arms of man

analogous = diff structure but same function
ex> wings of insects, wings of birds

topscore says analogous structures are similar in structure and dissimilar in origin.

I understand that they do not share the same ancestor.

But I don't understand when it says similar in structure.

I remember from a book(i forgot which) was saying that
wings of insects are membranous where as wings of birds are bony with feather meaning they should have different structure.

I am confused. Can someone explain this to me?

The answer I picked was dissimilar in both structure and origin.

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[Kneecoal]

i forget where i read it, but homologous structure: similar in structure, similar in origin - the example they used was wings of bat, fins of whale, arms of man (or something like that) - they're all appendages of kindof the same function (some kind of movement), and they all came from a previous ancestor because they're all mammals. an analagous structure is the same deal as the first part, except they didn't come from the same ancestor - i.e., wings of bat, wings of fly, wings of bird. hope this helps!

just to add so i'm not using just wings as the second example - the arms of a man are analagous to the wings of a bird as well.

 

[joonkimdds]

i forget where i read it, but homologous structure: similar in structure, similar in origin - the example they used was wings of bat, fins of whale, arms of man (or something like that) - they're all appendages of kindof the same function (some kind of movement), and they all came from a previous ancestor because they're all mammals. an analagous structure is the same deal as the first part, except they didn't come from the same ancestor - i.e., wings of bat, wings of fly, wings of bird. hope this helps!

just to add so i'm not using just wings as the second example - the arms of a man are analagous to the wings of a bird as well.

Are you saying that both membranous wings and bony wings have same structure?


I just googled analogous structure and the 1st thing that shows up says

"Body part in different species that is similar in function but not in structure that evolved in response to a similar environmental challenge."

So it agrees with me by saying that their structures are not similar.

 

[Philippines03j]

That is correct-

Homologuous- Similar structures on different species that come from a common ancestor.

Anologous- similiar structures on different species that developed that structure because of an adaptation to their environment.

One source that has it is Cliffs AP Bio. Just memorized it 2 days ago. Hope that helps

 

[joonkimdds]

Here is what Princeton AP BIO says

"In contrast to homologous structure, sometimes animals have features with the same function but that are structually different. A bat's wing and an insect's wing are examples."

It says structually different.

 

[bennijai]

I thought homologous structures were similar origin and structure with different function, where analogous was similar function (convergent evolution) but different structure and origin.

For analogous structures, I believe when you are looking at the anatomical structure, it is different but when you look at it superficially it has resemblance, so the wing of a butterfly and the wing of a bat.

 

[joonkimdds]

That is correct-

Homologuous- Similar structures on different species that come from a common ancestor.

Anologous- similiar structures on different species that developed that structure because of an adaptation to their environment.

One source that has it is Cliffs AP Bio. Just memorized it 2 days ago. Hope that helps

Could you double check your Cliffs AP Bio? All the sources I have is saying that analogous should have diff structure.

http://ask.reference.com/web?q=analogous+structure&qsrc=2446&modrw=1&l=dir&qsrc=2891&o=10616

just found another page saying
"Body part in different species that is similar in function but not in structure that evolved in response to a similar environmental challenge."


I am about to conclude that topscore is wrong.

 

[UCB05]

Here is what Princeton AP BIO says

"In contrast to homologous structure, sometimes animals have features with the same function but that are structually different. A bat's wing and an insect's wing are examples."

It says structually different.

By that, the book means that both wings serve the same purpose - to beat and create an upward force that causes flight. The are structurally different because the wing on a bat is a modified appendage evolved from the mammalian arm/hand, whereas the wing of an insect is an outgrowth of the exoskeleton with no evolutionary/embryological similarity to the bat wing.

"structurally" different in this case refers to the actual anatomical structure, not just the gross shape.

topscore probably means structure as gross shape, as in the way they look, which is kinda true. bad wording.

 

[Philippines03j]

Quotes from Cliffs

Homologous Structures "body parts that resemble one another in different species because they have evolved from a common ancestor. Because anatomy may be modified for survival in specific environmeents, homologous structures may look different, but will resemble on another in patter. The forelimbs of cats, bats, whales, and humans are homolous because they have all evolved from common ancestral mammal.

Anologous structures "body parts that resemble one another in different species, not because they have evolved from a common ancestor, but because they evolved independently as a adaptations to their environments. The fins and body shapes of sharks, penguins, and propoises are anolgous because they are adaptions to swimming.

Those are quoted directly from the book.

 

[Kneecoal]

yeah, i think you're thinking too much into this. homologous structures are similar and come from a common ancestor. analogous structures are similar but don't have a common ancestor, and rather developed out of evolutionary need for them. of course different species are going to have structurally different..err.. structures to some level. just try not to think so much into it. arms are these things that stick out from our sides. fins are some things that stick out of a fish's sides. so are wings with birds. analogous structures. boom.

NO need to think about the differences between membranous wings and bony wings. wings are wings are wings, in this case.

 

[ckmonster]

here

This is how I studied for homologous and analogous structures.

Homologous = similar structure, different function - common ancestor
ex> wings of bat, arms of man

analogous = similar structure, similar function - NO common ancestor (convergent evolution - when two unrelated species have close resemblances)
ex> wings of insects, wings of birds

topscore says analogous structures are similar in structure and dissimilar in origin. According to what I just wrote this is true!

I understand that they do not share the same ancestor.

But I don't understand when it says similar in structure.

I remember from a book(i forgot which) was saying that
wings of insects are membranous where as wings of birds are bony with feather meaning they should have different structure.

I am confused. Can someone explain this to me?

The answer I picked was dissimilar in both structure and origin.