Top 15 Jeffrey H. Schwartz Quotes

More than one hundred years ago, William Bateson suggested that studying the regulation and timing of development was the key to understanding evolutionary change. He was right.

The often heated and sometimes nasty debates that have taken place between gradualists and punctuationists, or between micromutationists and macromutationists, have been generated by the perception that there is only one evolutionary question, for which... there can be only one correct answer. ...But if we take a different approach, and assume that both sides of a typical evolutionary debate have something valid to offer, then the theoretical and methodological disagreements between different schools of thought may just be a matter of having the right answer to a different question.

As was demonstrated as long ago as the 1930s by the German experimental geneticist Hans Grüneberg, neither structural reduction or loss, nor structural addition, is a completely gradual process. Instead, the loss or gain of a structure is developmentally constrained to be more step-wise, or saltational.

A micromutation can produce what Goldschmidt would have described as macromutation leading to macroevolution. Since mutations in homeobox genes are inherited in the same way that earlier fruit-fly population geneticists understood the inheritance of the alleles for wing length or bristle number, we can appreciate that evolutionarily significant novelty—which, in turn, could result in the emergence of a new species—can be passed on from parent to child as easily and simply as eye color.

The observation of reduction in complexity in many groups or organisms after a structure has emerged in a full-blown state makes sense in terms of homeobox genes.

The sudden appearance of novelty is not, as Otto Schindewolf emphasized, an unusual aspect of the fossil record.

If Walter Garstang's suggestion is correct, and chordates did arise from a tunicate-like form by retaining the chordate features of their larval stage of development into adulthood, then the first chordates must have been affected by a regulatory mutation that kept the Manx gene activated for a longer period of time.

The Phoenicians were the Canaanites. Thus Phoenicia... was invaded by the Israelites, who eventually pushed the Phoenicians to the coastal fringe. Subsequently, the Israelites borrowed various cultural elements from the Phoenicians, including the first alphabet. Some groups of Israelites even adopted the god Ba'al and, presumably, the practice of child sacrifice.

Greeks and Romans alike engaged openly in a variety of sanctioned atrocities, including adult human sacrifice. ...according to ...Cicero, human sacrifice was not restricted to the western Phoenicians but was widely accepted among Mediterranean societies as a pious act that would please the gods.

From a succession of historians we learn of a particularly gruesome component of Carthaginian daily life: the routine and ritualized sacrificing of not just animals—animal sacrifice was a common religious activity of all Mediterranean cultures—but of infants and children. ...Greek and Roman historians were unanimous in their abhorrence of the Carthaginian practice...

Becoming a rock does not ensure safety. ...The blasting of windblown sands, the pummeling of waves, the corrosive secretions of mosses and lichens, and even the steady rhythm of a stream can, in time, reduce a seemingly indestructible boulder to a grain of sand.

The corpses of water-dwelling animals often sink to the bottom and become covered with sediment. The sediment tends to protect the dead body and even at times retain an impression of its shape and external anatomical details. This environment then provides the means by which the bones of the skeleton are mineralized. ...most land animals die and fall to the ground, without any chance of a freak flood casting them into an environment more favorable to fossilization.

The smaller the mammal, the more it is confined to smaller geographic areas. A small mammal is also more susceptible to subtle changes in climate and environment. ...On average, the absence or presence of smaller species provides more precise clues to past conditions in an area than does the information gained from study of the bone assemblages of the larger animals.

The processes of bone preservation are such that the farther back in time we go, the less there is.

The Bodo skull and the Kaprina and Shanidar Neandertal skeletons raise the possibility that two distinct, non-spaiens species of Homo had had rituals and cultural practices that we have assumed are only within the capacity of members of our own species.