It's the sheer astronomical mathematical complexity of DNA and living creatures that amazes scientists and makes some of them say "This could NOT have occurred by random chance!"
For example here's a rerun of one of my earlier stunning A2K posts-
The retina is lined with light-sensitive rods and cones-
Here's a typical rod, note the light-sensitive cells stacked up inside it..
..like a tube of Pringles-
There are
120 million tubes of Pringles (rods) in the human eye (and another 7 million cones), each one containing stacks of individual pringles which takes the numbers way off the scale, and scientists can't even begin to fathom how they "evolved", let alone explain how they "wired themselves up" like a printed circuit board and then connected themselves up to the brain-
-----------------------------------------------------------------------------------------------