Commenting on their findings, Grützner and his coworkers lamented: “This suggests an evolutionary link between mammal and bird-sex chromosome systems, which were previously thought to have evolved independently” Yet, Darwinians place mammals on the planet 100 million years before birds!
Supplementing what heyhey expressed so well, mammals and birds are both types of lizards, and lizards have a variety of sex mechanisms, including some that are ZW. The link between mammals and birds is that both come our of the ZW lizard branch.
Khamsi asks the obvious question: “What is the advantage of having so many sex chromosomes?”
Not every evolutionary trait is an advantage. Primates do not produce vitamin C because of an evolutionary mechanism know as genetic drift.
Sexual reproduction in animals with two sex chromosomes has a “selective disadvantage” of at least 50%—a disadvantage that will not budge!
Actually, there are many advantages to sexual reproduction, which is why it is the dominant form of multi-cellular life.
Evolution cannot explain the origin of two sex chromosomes—much less ten!
Again, the issue is not the lack of an explanation, but the presence of too many explanations, and no good way to choose among them.
As it turns out, the common “survival of the fittest” mentality cannot begin to explain the high cost of first, evolving, and then maintaining, the sexual apparatus.
The benefits outweigh the costs for multi-cellular beings.
Surely, to an open and honest mind, this beautiful complexity points to a Great Designer.
Actually, complexity points to a lack of a designer, if it points any way at all. Designers prefer simplicity.