By R. Emmett Tyrrell, Jr. on 5.21.09 @ 6:08AM
Chimpanzee and man go back some three billion years, it would
appear.
WASHINGTON -- This week a 47 million-year-old fossil was put on
display at New York's American Museum of Natural History.
Scientists accorded the event enormous attention, as did the
press. The creature may be related to us, though it looks like a
cat, not a chimpanzee, and certainly nothing like your mother or
father or even one of your more eccentric aunts or uncles.
Evolutionists tell us that of all the creatures known to science
we humans are most closely related to chimpanzees.
That is not the whole story, of course. According to a very fine
book that I have been reading, Why Evolution Is True by
Jerry A. Coyne, an evolutionary biologist at the University of
Chicago, mankind can be traced back over three billion years to
our most distant relatives, self-replicating molecules. The
fossil unveiled at the American Museum of Natural History is a
relative newcomer, but she (the creature was a young female) has
cleared up a debate among scientists. Anthropologists have been
pretty certain that we evolved from ape-like ancestors, but they
have been divided on precisely which one. There were two, the
family Tarsiidae -- whose descendants, the tarsiers, are jungle
creatures now living in Asia -- and the family Adapidae, who were
precursors of the lemur of Madagascar.
Scientists base their speculations on fossils that are rarely
complete. Some scientists have extrapolated our ancestors from as
little evidence as a tooth. The lucky ones have had a jawbone or
a rib or some other skeletal fragment. This week's fossil
displayed in New York is a complete skeleton, except for a
missing lower leg. From it evidence mounts that our ancestor is
the adapidae, the precursor of the lemur. "Lemur advocates will
be delighted," Tim White, a California paleontologist, is quoted
as saying in the Wall Street Journal, "but tarsier
advocates will be underwhelmed." Scientists are given to such
disputes, and then there are the creationists who doubt we have
any animal ancestors whatsoever. Let the debate continue.
What I have found fascinating in Coyne's book is how very old the
earth is. Some of his evidence comes from fossils and
measurements of the radioactivity in the layers of stone that
harbors the fossils. The radioactivity gives us a good idea of
the stone's age, and the progression of the fossils gives us an
idea of their steady development.
Scientists, by dating old rocks, have established that the earth
is 4.3 billion years old. The earliest fossils, those being
photosynthetic bacteria, trace life on the planet beginning about
3.5 billion years ago. Around 600 million years ago multi-celled
organisms appeared, for instance, worms and jellyfish. Then came
terrestrial plants and four-legged animals about 400 million
years ago. Mammals did not show up until 250 million years ago,
and birds can be found in fossil form dating from 50 million
years ago.
Coyne writes that "Humans are newcomers on the scene -- our
lineage branches off from that of other primates only about 7
million years ago, the merest sliver of time." Then just over
four decades ago Barack Obama was born, and just over six decades
ago Newt Gingrich.
Coyne and other evolutionary biologists have had their theories
fortified by the ability, starting three decades back, to
sequence the genomes of various species and discover genes shared
by related species, some that still work, some that do not thus
allowing us to go our merry way from, say, our relative the
chimpanzee. The key to this process, scientists say, is natural
selection. There are good genes that help us survive and
not-so-good genes that deny those who carry them the possibility
of survival.
Now creationists find all this highly dubious, but for me the
information has come as a great relief. The good news is that
human beings adapt. We have survived, according to my reading of
Coyne, for about 60,000 years, adapting to all sorts of
challenges, climate changes, dietary changes, plagues, and other
such unwelcome happenstances. The present hullabaloo over global
warming is much ado about nothing. Let the climate change, the
species Homo sapiens has survived 60 millennia. There is
no reason for the Obama Administration to tamper with the
automobile market. We can survive carbon in the atmosphere and
have since the last weak-gened member of Homo erectus
wobbled off. Unfortunately it is unlikely that the automobile
industry can survive politicians designing our cars, taxing our
gasoline, and supplying us with tiny vehicles that few Americans
want to buy.
topics:
Global Warming, Evolution
