is this correct?

[tRNA]

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similar structure same origin--> homologus

different structure same origin--> homologus

is this correct??? just want to make sure, cuz i have seen different definitions

thanks

 

[smarterray]

You are correct.

Homologous structures can be of different structure but same ancestral origin. For example, bat wings, whale fins, and the human hand all have similar skeletal structure, a result of having the same vertebrate ancestor. Chimpanzee hands and human hands look pretty similar and they come from the same ancestor, so these are homologous structures too.

Analogous structures are ones that are similar but of different ancestral origin. For example, bat and butterfly wings are similar in that they are very large and are used for flight; however, they are clearly not the same in origin and arised at different times during evolution. Analogous structures are examples of convergent evolution.

 

[tRNA]

thanks just found another Q, kaplan makes it very clear that DNA is the only molecule capable of self replication, but that's wrong, right...because RNA can self replicate too, campbell says RNA "may" have been fully capable of self replication, so do i take that as a Yes or No for the dat???
i searched in other sites..some are for and some are against as this involves the origin of life which is a controversial subject

 

[Mstoothlady2012]

similar structure same origin--> homologus

different structure same origin--> homologus

is this correct??? just want to make sure, cuz i have seen different definitions

thanks

I have never heard that definition of homologus

 

[tRNA]

I have never heard that definition of homologus

i got this info from my comparative anatomy class notes
take a look at the left hand side of the ancestry circle

http://www.esnips.com/doc/8b4ed481-8976-49e0-a15f-b44d25261d5a/Untitled-1

 

[151AND8TH]

it sounds like no one has a definite answer to this question. It almost seems like every day a new definition pops up...