"Descent of Man." How does the author structure paragraphs 1 and 15 to create an effect in the story?

The author structured paragraphs 1 and 15 in such a way that a vivid explanation was given about human beings and its ancestry.

The "Descent of Man" was published by Darwin. In the book, he explained that human beings and the African apes had a common ancestral background.

He stated that human beings had large brains size and we're intelligent which led to technological advancement. In the introduction of the book, Darwin stars the purpose of the text. He explained that it was to know if human beings came from an ancestor.

In other chapters of the book, he explained the differences that existed between the different human races and sexes. He also explained the role of women and how evolutionary theory is relevant to the society.

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closer examination, however, finds the mcdonald's kind of job highly uneducational in several ways. far from providing opportunities for entrepreneurship (the lemonade stand) or self- discipline, self-supervision, and self-scheduling (the paper route), most teen jobs these days are highly structured — what social scientists call “highly routinized.”  

true, you still have to have the gumption to get yourself over to the hamburger stand, but once you don the prescribed uniform, your task is spelled out in minute detail.  

faithful servants eumaeus and philaetius:

his ragged vest then drawn aside disclosed the sign conspicuous, and the scar exposed: eager they view'd, with joy they stood amazed with tearful eyes o'er all their master gazed:

these servants know ulysses by the scar he got when he was a child - so when he showed them the mark, they immediately knew this is truly their master and they hugged him, finally starting to believe his words.