Tradition in most cultures, including the Hebrew, dictates that he first-born son receives the inheritance or favor in the inheritance. This string of second-son inheritors is out of the norm and is used by God to prophesy of Christ.
Jacob the literal second son
Esau and Jacob were twins. Esau was born first and Jacob was born right on his heels. 
Esau's personality reflects that of the earthly man; the man of the flesh. He traded his birthright for a boiling pottage.
Jacob the riddle second son
Esau's characteristics also indicate his earthly nature in riddle and symbol. When he was born he was red in color.  The Hebrew word for red is 'adam'. The same as the name for the first man Adam. Esau was also hairy all over his body. Hair is a symbol for authority. In riddle is suggests that Esau was a man who gave authority to his body/flesh.
He traded his birthright for soup. In Hebrew this is zood nazid or 'pride' 'son of man's pride'.  This fits well with the image of Esau being earthly. When he asked for the pottage, he asked for the red (Adam) pottage, and his name was changed to Edom, which is spelled the same as Adam. 
Jacob was renamed Israel. Jacob lost all he had gained when he forfeited it during his reunion with Esau, but gained it all back as Israel.
Esau was threatened with death but did not die 
Jacob threatened with death but did not die 
He slept (died)  and awoke with God's blessing of fruitfulness.
Stone on the mouth of the well 
THe rods were striped 
Threatened with death 
Wrestled with God (underground) 
Next: Second son - Judah
- Ge 25:26 And after that came his brother out, and his hand took hold on Esau’s heel; and his name was called Jacob: and Isaac [was] threescore years old when she bare them.
- Ge 25:25 And the first came out red, all over like an hairy garment; and they called his name Esau.
- Ge 25:29 ¶ And Jacob sod pottage: and Esau came from the field, and he [was] faint:
- Ge 25:30 And Esau said to Jacob, Feed me, I pray thee, with that same red [pottage]; for I [am] faint: therefore was his name called Edom.
- Ge 25:32 And Esau said, Behold, I [am] at the point to die: and what profit shall this birthright do to me?
- Ge 27:42 And these words of Esau her elder son were told to Rebekah: and she sent and called Jacob her younger son, and said unto him, Behold, thy brother Esau, as touching thee, doth comfort himself, [purposing] to kill thee.
- Ge 28:11 And he lighted upon a certain place, and tarried there all night, because the sun was set; and he took of the stones of that place, and put [them for] his pillows, and lay down in that place to sleep.
- Ge 29:3 And thither were all the flocks gathered: and they rolled the stone from the well’s mouth, and watered the sheep, and put the stone again upon the well’s mouth in his place.
- Ge 30:37 ¶ And Jacob took him rods of green poplar, and of the hazel and chesnut tree; and pilled white strakes in them, and made the white appear which [was] in the rods.
- Ge 32:11 Deliver me, I pray thee, from the hand of my brother, from the hand of Esau: for I fear him, lest he will come and smite me, [and] the mother with the children.
- Ge 32:24 ¶ And Jacob was left alone; and there wrestled a man with him until the breaking of the day.