Why do you think that it needs to be? What you just made was an argument from ignorance. You need to support your claims of why evolution cannot develop new traits. We can provide articles of how new traits arise.
Though there are other facts the two easiest to understand are random mutation and selection. One cannot focus only on one. Both are needed for evolution. Variation, which includes more than random mutation, introduces new traits, neutral, good, and bad. Natural selection automatically weeds out the bad and keeps the good.
The dominant theory of evolution today is neo-Darwinism, which contends that evolution is driven by natural selection acting on random mutations, an unpredictable and purposeless process that has no discernable direction or goal, including survival of a species. And yet you want me to believe it created all life...
Most scientists until the latter part of the nineteenth century accepted some form of intelligent design, BTW.
In December 2003, the biology journal BioEssays published a special issue on
“molecular machines.” In the introductory essay to that issue, Adam Wilkins, the
editor of BioEssays, remarked, “The articles included in this issue demonstrate
some striking parallels between artifactual and biological/molecular machines. In
the first place, molecular machines, like man-made machines, perform highly
specific functions. Second, the macromolecular machine complexes feature
multiple parts that interact in distinct and precise ways, with defined inputs and
outputs. Third, many of these machines have parts that can be used in other
molecular machines (at least, with slight modification), comparable to the
interchangeable parts of artificial machines. Finally, and not least, they have the
cardinal attribute of machines: they all convert energy into some form of ‘work’.”
How, then, do biologists explain the origin of such structures? They don’t. In
2001, cell biologist Franklin Harold published The Way of the Cell with Oxford
University Press. In it he remarked: “There are presently no detailed Darwinian
accounts of the evolution of any biochemical or cellular system, only a variety of
wishful speculations.”