The Ancestor creature is a genetically-engineered creature that starts its life by ripping its way out of the womb and belly of the cow which bore it, it is a quadrupedal, fur-covered carnivore, with long claws and massive mouth containing large, sharp teeth. Probably the most characteristic feature of the Ancestor is the yellow-sail on the back of its head, a distinctively reptilian feature which perhaps ties the mammalian Ancestor with its reptile forebears.
Throughout the novel Ancestor, there is ample evidence of the creatures' predatory behavior.
The primary weapons of the Ancestor creatures are their long, sharp claws, which are used to cut, slash, and disembowel prey, and their many pointed teeth in long, powerful jaws, used for biting. When multiple Ancestors are in close proximity, there is evidence of cooperative hunting. This is seen in the latter half of the book, which shows multiple creature moving as a group. It is hinted that the distinctive yellowish sails or dorsal fins of the Ancestor creatures are used by them to communicate with each other.
The Ancestor creature seems to have a very high metabolism, were frequently motivated by hunger, and required a significant amount of energy to hunt.
The Ancestor creatures were the result of primary genetic project of the Genada Corporation. The creatures were based on the ancient Thrinaxodon which lived some two hundred million years ago. The Thrinaxodon was a small creature; tear shaped thick in the middle tail trailing off to extremely narrow hips rear legs stuck out at a 45 degree angle front legs stuck at less of angle sparse layer of slivery fur covered the lithe little body long whiskers. A creature such as the Thrinaxodon is believed to have given rise to all mammals.
The Genada scientists aggregate the genomes of multiple mammals including the data from the Human Genome Project. Celera Genomics sequenced the entire human genetic code using automated sequencing technology (bioinformatics=computerized biological data) and the genomes of thousands of mammals stored in big databases like GenBank accessible through the internet, public databases and animals Genada has sequenced themselves they have the genetic code of almost every mammal on the planet. Genada postulates that since mutating genes is the basis for evolution and not all genes mutate at the same rate there is a piece of the Ancestor's original DNA in at least one species of mammal. By using a molecular clock so to speak, they can gauge which sequences have changed and by comparing that gene to the same gene of another mammal they can tell which sequence is older or closer to the original Ancestors genetic code. Using the lowest common denominator to recreate the Ancestor creature.
Dr. Liu Jiandan created an evolution lab inside the computer with a program that statistically analyzed the entire genome based on the probability of the function of each gene sequence. The computer works with the combined genome, predicting the final form and function then making changes, predicting again and measuring probability for desired traits. It was just like evolution only in reverse and a million times faster. The Ancestor creature was created in this computer environment one nucleotide at a time. Since it is created from scratch Genada can ensure it is free of any viral contamination.
Once the full genome (genetic instructions for building an animal) was built, it was inserted in an egg taken from a surrogate mother, then the modified egg was placed back into the mother. Jian designed the genome to be a fast growing, roughly human sized animal that Genada could breed a herd of and use as low cost donors. The business model assumed that since Genada created the animal they would own it and therefore could charge whatever the market will bear for replacement organs.