Just when you thought you could get away from genealogies, here comes Shem and his descendants. But before you get sleepy on us, there are some things in his line that you should know. You should notice the substantial decrease in life spans with each successive generation, the overlapping generations, and a few facts about Abram’s family.

Shortened Life Spans

Shem lived to be 600 years old (v. 10-11).

• His son lived 438 years.
  
• The next 2 generations lived just over 400 years each.
  
• The next 3 generations each died before they reached 250 years.
  
• Abram’s grandfather only lived to be 148.
  
• Abram’s father died at 205.
  
• Abraham died when he was 175 years old (Gen. 25:7).
  

Can you see the trend here? Their life spans were cut to 2/3rds in the first three generations, and to just a little over 1/3rd in the subsequent generations. Today, doctors and scientists think it is a medical miracle to increase the life span of a man by just a few years. No, that’s not much of a miracle.

The fact is that something drastic happened to the atmosphere following the flood. And the shortened life spans that resulted will not be increased until Jesus comes back. Then, men will start living to the ages they did before the flood (Is. 65:20).

Overlapping Generations

Shem lived long enough to see his great-great-great-great-great-great-great-great-grandson Isaac born. That’s 10 generations! He and Abram were contemporaries for nearly 150 years. So, Adam could have told his great-great-great-great-great-great-grandson Lamech about creation, and Lamech could have told Shem (they were contemporaries for over 90 years), and Shem could have told Abram. So, Abram received the news of creation and all the intervening history third-hand. That’s pretty good when you consider that we’re talking about 2000 years of history!!

Abram’s family

Abram had two brothers (v. 27), a nephew named Lot and a niece named Milcah, who married Abram’s brother, Nahor, and a wife named Sarai, who was his sister (Gen. 20:12). Of course, there were other family members. But these are the important ones. Later, Abram’s servant took Rebekah, who was the granddaughter of Nahor and Milcah, as a wife for Isaac (Gen. 24:15). Marriages to sisters were allowed until Lev. 18.