Hypothesis: homologous structures are evidence of a common ancestor ? why is this correct ?

Yes, because homologous structures are different structures we have that other different organisms might have. humans and monkeys both have arms, although they are completely different species, this can tell scientists that they could have shared a common ancestor in the past, and may have evolved

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.