Homologous vs. Analogous

[DDSguyLA]

Can someone break these down??
I learned them;

Homolo = Same (similar structure) Same (similar origin)
Analo = Same (similar structure) Diff (origin)
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But sometimes I get them wrong and mixed up.

What do they have to do with function???

Thanks

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[Orgodox]

I use this trick. They both have 2 similar 1 different.
In homologos the different is function so it same orgin and looks same
In analogous the difference is orgin so other 2 are same ie function and looks similar

 

[osimsDDS]

For homologous: LOOK the same, same origin (it may be different function)
For Analogous: same function/look the same, different origin

In analogous they come from different origins but they have the same function because of equal enviornmental pressures that caused 2 differently non-related species to adapt to the same enviornment...this is usually termed convergent evolution

In homologous they come from the same origin and 2 related species can have structures that look the same but have different functions due to again different enviornmental pressures...this is termed divergent evolution because they started out being the same origin but then branched off due to different enviornmental pressures that caused them to adapt differently...

hope that helps

 

[osimsDDS]

I use this trick. They both have 2 similar 1 different.
In homologos the different is function so it same orgin and looks same
In analogous the difference is orgin so other 2 are same ie function and looks similar

I dont think homologous structures have to be the same function...they are different function i believe but look the same, but analogous structures are the same function

 

[DDSguyLA]

For homologous: LOOK the same, same origin (it may be different function)
For Analogous: same function/look the same, different origin

In analogous they come from different origins but they have the same function because of equal enviornmental pressures that caused 2 differently non-related species to adapt to the same enviornment...this is usually termed convergent evolution

In homologous they come from the same origin and 2 related species can have structures that look the same but have different functions due to again different enviornmental pressures...this is termed divergent evolution because they started out being the same origin but then branched off due to different enviornmental pressures that caused them to adapt differently...

hope that helps

Thanks man...

 

[osimsDDS]

usually they give you like animals and their structures which is annoying but you will have to know if their are related or not...

ex/ wing of an insect and leg of a horse, obviously not related at all and thus are analogous structures or not even homologous structures...

 

[Jennyollio]

Just a trick I made to remember this- I think of the lines in a capital A for analogous and how they converge together. And they start apart at the bottom because they came from different origins. I don't know if this trick will help anyone else but it works for me after years of always mixing the two up

 

[peyman2002]

I use this trick. They both have 2 similar 1 different.
In homologos the different is function so it same orgin and looks same
In analogous the difference is orgin so other 2 are same ie function and looks similar

I agree with you but flipper of a whale doesn't look like an arm of a human,in pattern they do but by just looking they don't.I don't think on the DAT they tell u by looking at the pattern or morphology.

 

[joonkimdds]

usually they give you like animals and their structures which is annoying but you will have to know if their are related or not...

ex/ wing of an insect and leg of a horse, obviously not related at all and thus are analogous structures or not even homologous structures...

is it true that wing of an insect and leg of a horse have the same function?
Can insects walk with their wings

 

[jay47]

usually they give you like animals and their structures which is annoying but you will have to know if their are related or not...

ex/ wing of an insect and leg of a horse, obviously not related at all and thus are analogous structures or not even homologous structures...

Not trying to burst a bubble or be a "know it all", but I'm pretty sure that the "wings of an insect and the legs of a horse are NOT analogous structures.

Analogous structures are just that, analogous. They are similiar in function, but not due to homology (similiar origin). Analogous meaning "showing an analogy or likeness"
http://www.merriam-webster.com/dictionary/analogy

For example, wings on an insect and wings on a bird both evolved completely separately, but are analogous becuase their function is the same.

However I don't think that insect wings and legs would be considered analogous, but your definitions are fully correct.

 

[pbure9]

is it fair to say that homologous are divergent evolution and analogous are convergent?

 

[joonkimdds]

is it fair to say that homologous are divergent evolution and analogous are convergent?

haha, i was thinking about the exact same thing and clicked this thread. I am glad you asked first

I think it's fair

 

[pbure9]

So homolgous are simliar in origin but not function and analogous are similar in function not origin. Where does structure fit in here? Homologous are similar anatomically but analogous are similar in appearance I would say. Can one then say that both are similar in structure? Lol. I just confused myself

 

[UCB05]

Structure may or may not match function or appearance. The point is just that homologous structures came from a common ancestor. The bones in the wings of a bat, dog paws/legs, human hands, whale flippers - all homologous and have metacarpels and phalanges.

Analogous structures perform similar functions, so may look structured the same way like the wings of an insect and wings of a bat, but they dont form from the same body plans. Another analogy: yo momma's like a window. Different evolutionary origins, but they're both always open.

 

[jay47]

is it fair to say that homologous are divergent evolution and analogous are convergent?

Yeah, that pretty much sums the whole thing up.

 

[ethanyoo726]

HOMOLOGOUS STRUCTURES: Same origin, similar structure, have different functions, may or may not look similar. usually arises from divergent evolution.

ANALOGOUS STRUCTURES: Not from same origin, does not have similar structure, have the same functions, may or may not look similar. Usually airses from convergent evolution. Similar environmental factors all push the two organisms into developing structures with similar functions, but have no common origin.

 

[americanpierg]

HOMOLOGOUS STRUCTURES: Same origin, similar structure, have different functions, may or may not look similar. usually arises from divergent evolution.

This has been said and repeated like 20 times in this thread already, but this is NOT the case. Homologous structures can have different functions, but not always like its being stated in this thread. The front legs of a dog and the front legs of a cat. Homologous? Yes. Different functions? No.

Basically, the only thing separating the two is the origin. Analogous structures may look and function the same, but are of different origin. homologous structures may look and function the same, and are also of the same origin.