The "very-recent" evolution of human beings from non-human
hominids is now quite well documented.
* One step back, 45,000 years ago, we find numerous well-preserved
skeletal remains of Neanderthal man in Europe. Although they
made beautiful stone tools, these people seem to have left no
remains of art -- no decorative carvings, no cave paintings,
Neanderthalers were different from you and I -- they had a
longer, lower cranium, much larger teeth and stronger jaws,
and stronger limb bones with a noticeable curvature.
Human remains intermediate between the Neanderthal forms
and modern humans are known from Shanidar in Iraq and from
caves on Gibraltar.
* Two steps back, remains of _Homo_erectus_ are known from
many many places in the Old World -- Africa, Europe,
southern Asia, Java, and China. Again, the remains are
numerous, and some sites are very well documented and have
been carefully excavated. _H._erectus_ was so clearly
not a modern human that you would immediately notice him
or her in a crowd, even if shaved and dressed in modern
clothes -- short, with a low, sloping forehead, heavy brow
ridges, projecting jaws, and a small cranial capacity.
Their tools were primitive compared to the Neanderthalers,
and slow to change -- the basic stone-axe culture seems to
have been pretty stable for most of a million years.
Forms intermediate between _H_erectus_ and later hominids
are known from several sites in Africa. Perhaps the
most famous is ER 1420.
* Three steps back, anthropologists have found the remains
of Australopithecus species in many sites in East Africa.
These are apes, more man-like than any apes living today,
that are found in older sediments than any _H_erectus_
remains. At least two, and possibly more distinct species
have been identified: a gracile form, which is possibly
the ancestral human lineage; and a robust form with really
unbelievably massive jaws and teeth, that seems to have
specialized for a rough low-grade vegetarian diet.
Forms intermediate between Australopithecus and _H._erectus_
are known from the Lake Turkana/Lake Rudolph areas
of Africa -- perhaps the best known is "Lucy", an
almost-complete skeleton of a young female who walked
upright and had a larger brain than the Australopithecines.
There you have it, Jim. A continuum of transitional forms has
been found in the last 50 years that clearly documents the
transition between ape and human being. There is no "missing
link" problem in physical anthropology any more, hasn't been
for almost 20 years.
Given this, it hardly seems necessary to mention Archeopteryx,
the transitional form between reptiles and birds --
Nor the crossopterygian fishes of the Devonian, transitional
between bony fishes and amphibians --
Of course, there are none so blind as he who will not see.
References: Gowett, "Ascent to Civilization", 2 ed. (*wonderful*)
"Fossil Man" (can't remember the author)
"Avenues to Antiquity", volume of Sci. American reprints