The series is based on the popular New York Times bestselling book series collectively known as The Expanse,  written by Daniel Abraham and Ty Franck (under the pen name James S. A. Corey). Abraham and Franck will be show producers.
A tortoiseshell cat is a coat color where the cat is a molted brown cat with black, reddish, or orange patches. They can also have white paws. Tortoiseshell cats have unique genetics. The vast majority of tortoiseshell cats are female, because two X chromosomes are required to produce black, gold and orange coloring.
The mutation that gives male cats a ginger-colored coat and females ginger, tortoiseshell, or calico coats produced a particularly telling map. The orange mutant gene is found only on the X, or female, chromosome. As with humans, female cats have paired sex chromosomes, XX, and male cats have XY sex chromosomes.n genetic terms, calico cats are tortoiseshells in every way, except that in addition they express a white spotting gene. There is however one anomaly: as a rule of thumb the larger the areas of white, the fewer and larger the patches of ginger and dark-or-tabby coat.