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years. If such a fossil juxtaposition occurred, and it was not the product of some geological anomaly (such as uplifted, broken, bent, or even flipped strata—all of which occur but are traceable), it would mean that there was something seriously wrong with the theory of evolution.
    Evolution also posits that
modern organisms should show a variety of structures from simple to complex, reflecting an evolutionary history rather than an instantaneous creation
. The human eye, forexample, is the result of a long and complex pathway that goes back hundreds of millions of years. Initially a simple eyespot with a handful of light-sensitive cells that provided information to the organism about an important source of the light, it developed into a recessed eyespot, where a small surface indentation filled with light-sensitive cells provided additional data on the direction of light; then into a deep recession eyespot, where additional cells at greater depth provide more accurate information about the environment; then into a pinhole camera eye that is able to focus an image on the back of a deeply recessed layer of light-sensitive cells; then into a pinhole lens eye that is able to focus the image; then into a complex eye found in such modern mammals as humans. All of these structures are expressed in modern eyes.
    Further,
biological structures show signs of natural design
. The anatomy of the human eye, in fact, shows anything but “intelligence” in its design. It is built upside down and backwards, requiring photons of light to travel through the cornea, lens, aqueous fluid, blood vessels, ganglion cells, amacrine cells, horizontal cells, and bipolar cells before they reach the light-sensitive rods and cones that transduce the light signal into neural impulses—which are then sent to the visual cortex at the back of the brain for processing into meaningful patterns. For optimal vision, why would an intelligent designer have built an eye upside down and backwards? This “design” makes sense only if natural selection built eyes from available materials, and in the particular configuration of the ancestral organism’s pre-existing organic structures. The eye shows the pathways of evolutionary history, not of intelligent design.
    Additionally,
vestigial structures stand as evidence of the mistakes, the misstarts, and, especially, the leftover traces of evolutionary history
. The cretaceous snake
Pachyrhachis problematicus
, for example, had small hind limbs used for locomotion that it inherited from itsquadrupedal ancestors, gone in today’s snakes. Modern whales retain a tiny pelvis for hind legs that existed in their land mammal ancestors but have disappeared today. Likewise, there are wings on flightless birds, and of course humans are replete with useless vestigial structures, a distinctive sign of our evolutionary ancestry. A short list of just ten vestigial structures in humans leaves one musing: Why would an Intelligent Designer have created these?
     
    1.
Male nipples
. Men have nipples because females need them, and the overall architecture of the human body is more efficiently developed in the uterus from a single developmental structure.
    2.
Male uterus
. Men have the remnant of an undeveloped female reproductive organ that hangs off the prostate gland for the same reason.
    3.
Thirteenth rib
. Most modern humans have twelve sets of ribs, but 8 percent of us have a thirteenth set, just like chimpanzees and gorillas. This is a remnant of our primate ancestry: We share common ancestors with chimps and gorillas, and the thirteenth set of ribs has been retained from when our lineage branched off six million years ago.
    4.
Coccyx
. The human tailbone is all that remains from our common ancestors’ tails, which were used for grasping branches and maintaining balance.
    5.
Wisdom teeth
. Before stone tools, weapons, and fire, hominids were primarily vegetarians, and as such we chewed a lot of plants, requiring an extra set