THE FACT OF EVOLUTION

• Recent evolution: a small number of house sparrows invaded the USA from Europe, and all are now descended from those initial founders.  Analysis of their body size now shows that they are smaller in the South, where it is hotter, and larger in the cooler North.  They have evolved.
• Geographic variation is common, and many species can be divided into well-marked "subspecies", such as the difference between the carrion crow in England and the "Hoodie" or hooded crow in Scotland.
• Taxonomists often have a very hard time telling strongly differentiated subspecies from "good" species because all gradations between species and subspecies exist in nature.
• We can recreate certain species, particularly hybrid species, or species such as in many plants resulting from chromosomal doubling, in the laboratory.
• The fossil record confirms evolution by a providing temporal dimension.  The order of finds in the fossil record corresponds with evolutionary relationships.
• All living things share the same genetic material (nucleic acids) and indeed have virtually the same RNA code for translation to amino acids.
• Closely similar species have closely similar DNA, both in the genes that actually code for proteins, and also in non-coding DNA that has no function.

It is hard to explain all of this as an accident, or as due to design by a creator.  It seems perverse not to make the obvious link between the evolution of geographic variation and subspecies today and the factors that produced geographic variation and the origin of species in the past.  Genetic similarities correspond to overall resemblance between species and suggest that actual evolutionary relationships are the most likely explanation for both genetic and overall similarity between organisms.