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Didelphodon lived in the late Cretaceous period, about 65 million years ago. It was a pouched mammal about the size of a badger, making it one of the largest mammals of the Mesozoic era. It lived in the shadow of dinosaurs, was probably a nocturnal scavenger living on small reptiles, insects and dinosaur eggs.
According to Carl Sagan in "The Dragons of Eden", "The timescale for evolutionary or genetic change is very long. A characteristic period for the emergence of one advanced species from another is perhaps a hundred thousand years...". But in 65 million years there are only 650 periods of 100,000 years - that's 650 'ticks' of the evolutionary clock. Or look at an example of recent evolution in humans. Toes have evolved from fingerlike appendages which were used for grasping and swinging, like we see in monkeys today. But the big toe today in humans plays an important role in balancing while we are in motion. This evolution constitutes a respecialisation - the adaption of an organ system originally evolved for one function to another quite different function - which took a few million years. So evolution is a slow process, creating a new species is time consuming.
So how do we get from Didelphodon to, for instance an elephant, in 650 increments. How do you get from the snout of a Didelphodon to the perfectly formed elephant trunk with 150,000 muscles in only 650 ticks based on random mutations? Even to get to the size of an elephant's brain, which is hundreds of times bigger, with hundreds of times more neurons than the Didelphodon's would be quiet an achievement. Or to get to a whale, with no pelvis, blow holes up top, temperature controls to allow them to swim in artic waters, and they consume salt water rather than fresh water. How is it possible to get from the small four legged mammals of 65 million years ago to the huge diversity of size, shapes and complexities of mammals we share our planet with today. Surely 65 million years is too short a period of time for this to happen !
 Evolution of the human brain also presents a problem. Current evidence indicates that modern humans evolved from Homo Erectus (who lived about two million years ago). Based on the skull size of Homo Erectus, their brain capacity was of the order 800cc-900cc (cubic centemeters). Modern human brain size averages about 1500cc. So in about 2 million years, evolution almost doubled the size of the Homo Erectus brain to create the human brain that we have today. Our brains contain about 100 billion neurons today, so therefore in about 2 million years, evolution added 50 billion neurons to the Homo Erectus brain, redesigned the skull to accomodate these extra neurons, and redesigned the female pelvis to allow the large skull through during birth.
So how is this supposed to have happened? Is it possible that small changes in DNA patterns, say a point mutation (replacement of a single base pair), during embroynic development can have a large effect on the outcome, and perhaps be responsible for speeding up the process of evolution and the creation of new species ?
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