by George McCready Price (1870-1963)
(This was ©1925 by Southern Publishing Assoc.)
PUBLIC DOMAIN - FREE to Copy & Use
Chapter Six - Degeneration
Linnæus (1707-1778), from whom we get our method of the scientific naming of plants and animals, was somewhat less extreme, for he allowed for the effects of degeneration and for those of hybridization. He adopted the word "species" to represent all the individuals which he thought had descended from an originally created pair of animals or an original stock of plants. In the long lapse of time since his day, his names of "species" have in great multitudes of cases been elevated to generic rank, with consequent splitting up into more minute subdivisions, called also "species." Whereas Linnæus declared that the botanist ignores minute varieties, the recognition of these minute varieties and the dignifying of them with specific names has gone merrily on both in botany and in zoology; with the result that, as a general thing, the "species" of Linnæus would correspond about with our "genera."
The Mania for Creating Names
Some fifty years ago, Professor Jordan, a French botanist, gave a strong impetus to this mania for creating new names. He undertook to determine by experiment just how minute are the varieties that will continue to breed true to seed. He found that as a general rule those "minute varieties" which Linnæus had determined to ignore, would continue to come true to seed, just as surely as would the ones which Linnæus had called "species."
Thus for the last half century or so we have had to deal with two kinds of species: (1) the species of Linnaeus, or "Linnaean species," and (2) those of Jordan, or "Jordanian species," the latter being also called "physiological species."
This work of Jordan was long before the rise of Mendelism. With the great stimulus which the latter system has given to breeding experiments, still more minute subdivisions are now found also to keep true to the original type. For example, the U. S. Department of Agriculture recognizes 250 kinds of wheat, "all of which breed true," as Hall and Clements remind us, "and would thus come to be species," if we were to follow Jordan. The authors just quoted from are urging a return to the conception of Linnaeus, and a reversal of the mania for "splitting" which has prevailed for over a generation. They declare that, "if taxonomy is to be either stable or usable, it must rest upon the species concept of Linnaeus and the practice of eminent taxonomists from his time to the present."—"The Phylogenetic Method in Taxonomy" (1923), p. IB. The Carnegie Institution of Washington.
It would thus appear that we have arrived at a sort of box-within-a-box notion of our units of classification. The minute units of Jordan will breed true, as will also the larger units of Linnaeus. Even the latter may not be large enough to include all that have descended from common ancestors. In Chapter III we have seen how H. B. Guppy, the English botanist, advocates the idea that the great families and genera must have appeared first, some time in the long ago, "subsequently breaking up into other genera and species." This view is being strongly supported by many prominent scientists, and appears to me to be in harmony with all that we now know regarding these matters.
Species are evidently not absolutely unchangeable, as was long taught
by both scientists and theologians. But before asking ourselves whether
the general tendency of these changes which we admit has been upward or
downward, we must note some general facts bearing on the subject. Many
of my readers are doubtless familiar with the very striking and characteristic
types of plants found in the desert parts of the United States. But they
are not confined to these regions, any more than the blind fishes and crustaceans
are confined to the Mammoth Cave of Kentucky. But as the blind animals
found in the caves of Europe, of South America, and of Australia seem to
be the modified descendants of the particular types represented in their
own particular surroundings, so do the plants and animals of the desert
parts of Africa, Asia, and Australia seem quite generally to be the greatly
changed representatives of other plants and animals not greatly distant,
but living amid more normal surroundings.
Let us take another class of facts. Geology has very clearly proved
that the world before the Deluge (I am now speaking in terms of the
New Geology) had a very remarkably mild climate all over, that is,
mild temperatures extended into the extreme polar latitudes. We find plenty
of fossils of oaks, elms, birches, hiagnolias, grapevines, sequoias, even
palms and other semi-tropical trees, away within the Arctic Circle. Not
only so; but we also find many coral limestones in these localities, proving
that the ocean was as mild and warm as the land climate. Moreover, we find
that these conditions prevailed without interruption throughout all the
period of time shown by the fossils; as A. R. Wallace expresses it, throughout
the entire geological series "we find one uniform climatic aspect of the
fossils." This means that this mild, springlike climate prevailed uninterruptedly,
until the great change came that brought in the modern conditions.
From all this we are compelled to draw the same lesson that we have already drawn from a study of the denizens of the desert. In both extreme conditions we find a multitude of plants and animals that must have descended from others that were undoubtedly so different in both appearance and in habits that scientists would feel compelled to place the two in separate species, probably in separate genera. This conclusion seems to me unavoidable. Multitudes of living organisms have undergone very striking changes, in passing from the ancient world to our modern one.
The Origin of Human Races
Accordingly, we are compelled to believe in the origin of many distinct "species" by some sort of natural process within the period of time covered by human life; for it is a well authenticated fact that man lived before the great world-changes which are revealed to us by geology.
But some equally well established facts regarding the human race itself
have a very important bearing upon the problem we are here considering.
Fifty or seventy-five years ago, Louis Agassiz and many other scientists
taught that the human race is not a unit, but that it is made from several
original stocks. This is the theory of the Pre-Adamites, which was widely
taught about the third quarter of the nineteenth century. We have discarded
this error; yet the problem of the great diversity in the races of mankind
is still unsolved. For several races of mankind are quite as distinct from
each other as are many "species" among animals and plants. Undoubtedly
there has been more mixture of these races of man than there seems to be
now going on between the various species of animals and plants. But even
among the latter many recent writers think that hybridization has played
an important part in producing new "species."
The Great Dispersion
The believer in the Bible will very reasonably connect this formation of the distinct races of mankind with the great Dispersion, as recorded in the eleventh chapter of Genesis. Such a segregation of mankind into several distinct races would assist in accomplishing the same purpose as the confusion of tongues and the compulsory dispersion of the separated units of the race, which was (as stated in the Bible) to insure the peopling of the entire earth, and to prevent the formation of a great, crushing, centralized world-despotism, which was even then threatening to stifle the free development of human liberty.
But these facts regarding mankind throw much light upon the problem of the origin of "species" among both plants and animals. It was a completely desolated earth that lay out before the survivors of that great world-disaster. Even the animals that had survived must have felt the extreme of hardship and privation, as they spread abroad. But —
"The world was all before them, where to choose
That tendency toward "adaptation" that we see every-where among living
organisms, could not fail to produce very quickly great changes in the
animals and plants, resulting in a great multiplication of different kinds,
or "species" in the more restricted sense of this word. Just as we see
millions of cells busily engaged in healing a wound or in combating a disease,
so we know that this same Power behind nature was here intent on helping
the world as a whole, which had been terribly wounded and was sick almost
to death. Evidently it was in this way that much of the great diversity
was produced which we see around us among the plants and the animals.
And yet, as we compare our present larger animals, such as the
bear, the lion, the elephant, the hippopotamus, the elk, or the beaver,
and hundreds of others might be mentioned, with those superb "giants of
the prime" that we find as fossils in the Pleistocene beds of all the continents,
we cannot be blind to the marked evidences of degeneracy among the modern
kinds. This is not confined to the mammals; it is an almost universal phenomenon
throughout the animal kingdom. As Sir William Dawson has expressed it,
"All things left to themselves seem to degenerate."
Regarding the Los Angeles skeletons recently discovered, we are not yet sufficiently familiar with all the facts involved to enable us to pronounce definitely.
But from all these facts, we learn that degeneracy and not progressive evolution has dogged the footsteps of all created forms, including man himself.