Before I get into the real purpose of this post, why genealogy is awesome, I feel I should explain a bit about how I make decisions about sims in my game.
Now, if I have a specific idea for a sim or type of sim that I want to make, then that's what I make. Usually, when in create-a-sim, I take full control over the sims name/traits etc. But once in the game, as my families have children, I let "fate" do it's things.
For traits and aspirations I have a numbered list. Then I used a random number generator to make the decision for me. So my sim just aged up and I need a trait, random number generator gives me a 12 and that sim now loves the outdoors.
For a baby's last name (since the parents don't have the option to take each others names) I hyphenate the names. Mother's-Fathers. When those children grow up and have children, their children will have a hyphenate using the second part of their parent's names (aka the father's name is dominate as if the wife took the husbands name). Let me give you an example that should make this easier to understand.
John Smith marries Lisa Law. They have a baby girl Cindy. Cindy's last name would become Cindy Law-Smith. Cindy Law-Smith grows up and marries Carl Jones-McCormick. They have a son named Ted. Ted's last name would then be Ted Smith-McCormick. If they ever change it so couple's can take on their spouses last name then I will only rarely use hyphenated names. Children created in create-a-sim (using genetics or otherwise) will have one last name, the same one their parents share.
First names I do random. First I'll go to the random number generator and input the range of 1-26 (for the 26 letters of the alphabet). The number the generator gives me tells me what letter the new baby's first name will start with. If the generator gives me a "4" then the baby's first name will start with the letter "D" which is the 4th letter of the alphabet. But that just gives me the first letter. I now go to the dice button that allows you to have the game generate a name for you. The first name that pops up starting with the letter chosen by the generator, is their name. So in this example the generator gave us a 4 which means letter "D". I click the dice: "Tim"...no..."Mark"...no..."David"...David it is!
So now that you know that, let me introduce you to a very extended family
(Ignore the lazy photo-shopping, I just wanted to get everyone in the same picture.)
Ed and Daphne are married and have a son Milton. Daphne had an affair with Farland and had triplets Aisha, Kelsi and Elsi. Farland left Daphne for his now girlfriend Justine. They had twin boys Junior and Sam. And it's that kind of craziness that is the reason family trees/genealogy are needed!