Question

Similarities between seemingly unrelated organisms can be explained by Darwin’s theory that organisms come from common ancestors. Is it true or false?

Answer 1

Darwin's theory with relation to similarities amongst unrelated organisms looks at either similar form or similar function of appendages and from this it is postulated that some organisms have common ancestors based on these similarities. A broad example would be the fact that most vertebrates (organisms with spines) stemmed from one or a group of common ancestors, while invertebrates (lack of a spine) are related to common ancestor or groups of common ancestors. So the answer to the question is yes, it is true.

Answer 2

Answer: The given statement is True.  

Charle's Darwin ( who was a British naturalist) described evolution as "descent with modification," according to which species change over time, and ultimately give rise to new species.

In other words species are descended from old lifeforms, which modified over a period time due to some change in their environment. This is considered as the backbone of his Theory of Evolution that he called Natural selection.

Therefore, the given statement is True as the unrelated organisms have descended form a common ancestor ( depicting  similarities)  with certain modification in them during their course of evolution.