Cycloptic Cat

There’s a school of thought that biological evolution comes in two forms: creeps and jerks. Intuitively, these terms describe the rate and magnitude of the individual evolutionary step. Various non-believers in evolution will try to convince you, often with specious arguments, that significant physical change is impossible, particularly over one generation. Their argument is one random mutation does not have that much influence on a species' form. However, scientists are starting to show genetically that this isn’t the case, and that a single mutation can have a knock-on effect which creates a significant morphological change in the species.

Enter this newly born chimera: a cycloptic cat. Scientists were dubious, naturally, at first but apparently:

…medical authorities have a name for the bizarre condition.

"Holoprosencephaly" causes facial deformities, according to the US National Institute for Neurological Disorders and Stroke.

In the worst cases, a single eye is located where the nose should be, according to the institute's Web site.

Admittedly, I can't see any great advantages in having one eye, hence why most creatures have two or more. However, this crazy kitten shows us that it is indeed possible for a significant physical change to occur over one generation (unless, of course, both parents are cycloptic).

Now, if this cat did have an advantage over regular cats, and it lived in a relatively small population (which are historically quite common due to various extinctions and geographical isolations), you would see the evolution of a new species. All you would need is a little time.