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The greatest riddle of evolution has been
the following puzzle: while Darwin argued that new species
emerge through a slow, gradual accumulation of tiny mutations,
the fossil record reveals a very different scenario -- the
sudden emergence of whole new species, with no apparent
immediate ancestors. This discrepancy has fueled heated
debate among evolutionary theorists and has provided unfortunate
fodder to creationists, who see it as proof that evolution
doesn't happen at all.
Now, in this provocative and timely book,
leading paleoanthropologist Jeffrey Schwartz resents a groundbreaking
and radical new theory of evolution, which brings together
evidence from genetics, paleontology, embryology, and anatomy
to solve this great outstanding riddle. Central to the new
theory is the recent discovery of a special kind of gene,
known as homeobox genes, which can cause dramatic mutations
that express themselves suddenly in the form of a new species.
Such a new species will appear to have arisen out of thin
air, with no lineage of ancestors. The new theory preserves
natural selection, but shows that it is not the primary
engine driving evolution, after all.
Writing with graceful prose and the expert
knowledge only an insider can bring, Jeffrey Schwartz begins
by taking readers on a fascinating journey through the whole
history of evolutionary thinking and discovery, recounting
the major events and disputes. He also introduces the intriguing
puzzles encountered along the way in the study of human
evolution and shows how, despite early alternative theories
advanced by some of the greatest scientific minds of the
nineteenth and twentieth centuries, gradualism became a
matter of scientific orthodoxy. His account includes the
stories behind such highlights as the infamous Piltdown
hoax and the remarkable discovery of the astonishingly complete
Lucy skeleton.
Schwartz then introduces the series of important
recent events in developmental biology and genetics that
paved the way to his new theory, culminating with the discovery
of homeobox genes. This surprisingly small set of key regulatory
genes controls everything about the way an animal develops.
A slight variation in one of these crucial genes can make
the difference between an embryonic limb bud developing
into a fin or a foot, an arm or a wing. The key insight
Schwartz presents is that a dramatic mutation in one of
these genes will be passed on silently, unexpressed, through
generations until that mutation is carried by a large enough
portion of the population that it will suddenly express
itself in bodily form in a number of individuals in a short
period of time, creating a new species.
Sudden Origins is a provocative and
important book that will change the debate about evolution
and challenge a number of popular ideas premised on the
foundation of Darwinism. This book is crucial reading for
anyone who has ever pondered the mysteries of our own evolutionary
heritage.
Jeffrey H. Schwartz, Ph.D., is a professor
of anthropology at the University of Pittsburgh and the
author of the critically acclaimed The Red Ape and
What the Bones Tell Us. He is also coauthor, with
Ian Tattersall, of the forthcoming landmark three-volume
work, The Human Fossil Record.
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