Origin of the Species
The full title of Charles Darwin's book from 1859 is "On the Origin of Species by means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life". The underlying argument was that white humans had "out evolved" black humans and were superior.
Natural selection, survival of the fittest, or adaptation, is observed in the natural world and this is sometimes referred to as "micro evolution". Those animals that are the strongest, healthiest, or most adaptive to their environment are more likely to survive and go on to reproduce. The weaker animals, unable to adapt, are less likely to survive.
Charles Darwin catalogued a huge number of observations relating to all sorts of different animals - finches, moths, beetles, dogs, etc. However, all that he saw was animals adapting to their environment, changing slightly over time ... but finches were still finches, moths still moths, dogs were reproducing more dogs.
The evolutionist biologists Fagerstrom, Schuster and Szathmary stated in an article published in Science magazine in 1996: "Major transitions in evolution — such as the origin of life, the emergence of eukaryotic cells, and the origin of the human capacity for language, to name but a few — could not be farther away from an equilibrium. Also, they cannot be described satisfactorily by established models of microevolution."

Predictions of the evolution model,
  • Transitional forms
  • Beneficial mutations
  • Things getting better
  • New species
Predictions of the creation model,
  • Separate, distinct kinds
  • Intelligent design in nature
  • Tendency for decay
  • Extinction of species

There is no evidence observed in the natural world that one kind of animal can produce a completely different kind (such as a dog producing a cat).
This is a significant challenge for evolutionary theory. Some fossil evidence showing these transitional or intermediate species, between 2 kinds would transform the argument, and yet have not been forthcoming. As Professor Brian Goodwin (Biologist) pointed out in 1995 "the origin of species - Darwin's problem - remains unsolved.".
The actual evidence supports the creation model much more strongly than the evolution model.
Many people have taken the evolution of species model and turned it into a philosophy for life (see atheistic evolution etc). For example, Marxists used Darwin's theory to support their cause.
Evolution removes God from the equation and it is a model with many holes.
In summary, "Both the origin of life and the origin of the major groups of animals remain unknown" Alfred Fisher, Evolutionist, Groller Multimedia Encyclopedia, 1998 fossil section