Land of the Lost in Space meets the Brady Bunch

As a kid growing up in the 1970s, I watched all these shows and used to think that the Marshalls were actually members of the Bradys. Will looked like Greg, Holly looked like Cindy, and Rick looked like Mike. I guess it was the hair. Later on I noticed that Holly looked like a blond version of Penny Robinson during the 2nd season of Lost in Space with her bangs and braided hair. Coincidentally, both characters had a brother named Will.

The shows also bridged the mid '60s and mid '70s:
Lost in Space 1965-1968
The Brady Bunch 1969-1974
Land of the Lost 1974-1977

"Who knows, Mr. Gilbert, what a limit really is." Lincoln Bond, "Toward The Unknown", 1956