To refute Intelligent Design's claims that examples of apparent design in Nature demand a 'designer', scientists point to nature's many examples of lack of design (or at least lack of good design.)
One favourite is the recurrent laryngeal nerve - a cranial nerve that goes from the brain to the larynx via a tube near the heart. In fish, this path is a direct route. In humans however, looping around the aorta requires that the nerve travel down the neck before swooping back up. In giraffes, this same circuitous path means that the nerve can grow to greater than 3 m in length.
Would not a Big-D designer, sitting down at the drafting table with their coffee and thinking 'OK, something with a long neck today, maybe some spots' have the nerve go straight from the brain to the larynx (a distance of some few inches) - rather than taking a ridiculously inefficient 'redirect' route?