Encyclopedia of Evolution.pdf - Online Reading Center

0 living fossils
admired. The genus name of a small herbaceous plant of the
north woods, Linnaea borealis, honors Linnaeus, and the
species name of Abutilon theophrasti, the velvetleaf weed,
honors the Greek philosopher Theophrastus. Both amateur
naturalists and professional scientists yearned for the immortality
that would result from having a plant named for them.
Even though he did not even think about evolution,
Linnaeus included in his writings some intermediate forms
based on hearsay. He was willing to believe them because he
accepted the concept of the Great Chain of Being (see scala
naturae). For example, he wrote about strange species of
humans such as Homo ferus, a feral human on all fours and
unable to talk, and Homo caudatus, man with a tail. Linné
died on January 10, 1778.
Further Reading
Gould, Stephen Jay. “Ordering nature by budding and full-breasted
sexuality.” Chap. 33 in Dinosaur in a Haystack: Reflections in
Natural History. New York: Harmony, 1995.
Schiebinger, Londa. “The private lives of plants: Sexual politics in
Carl Linnaeus and Erasmus Darwin.” Pages 121–143 in M. Benjamin,
ed., Science and Sensibility: Gender and Scientific Enquiry
1780–1945. New York; Oxford University Press, 1991.
———. “The loves of the plants.” Scientific American, February
1996, 110–115.
living fossils Living fossils is the popular term given
to modern multicellular organisms that closely resemble
forms that have been known from the fossil record for at
least several million years (see figures and table). During
their time on Earth, these organisms have experienced stasis
(see punctuated equilibria) and stabilizing selection
(see natural selection). While in most cases evolution
has favored change and diversification, in these cases it has
favored stability. For more information about these examples,
see gymnosperms, evolution of; seedless plants,
evolution of; invertebrates, evolution of; fishes,
evolution of.
Lucy See australopithecines.
Lyell, Charles (1797–1875) Scottish Geologist Sir Charles
Lyell changed the science of geology into its modern form by
leading scientists away from catastrophism and toward
uniformitarianism, a theory that had been proposed earlier
(see Hutton, James). Although uniformitarianism is no longer
accepted in the form that Lyell proposed it, it was Lyell
who led geologists to understand that the history of the Earth
has occurred by the operation of natural laws over a long
period of time. Lyell’s geological theories laid the groundwork
for the development of evolutionary science (see Darwin,
Charles).
Born November 14, 1797, Charles Lyell had a keen
interest in natural history as he grew up. His father was a
botanist, and young Lyell collected and studied insects. Lyell
became interested in geology when he entered Oxford University
and attended lectures by Rev. William Buckland.
“Living Fossil” Plants and Animals
Relatively
Taxonomic unchanged
Organism category since
Plants:
Dawn redwood gymnosperm Pliocene Epoch
(Metasequoia) seed plant
Ginkgo gymnosperm Jurassic period
(Ginkgo) seed plant
Monkey puzzle gymnosperm Triassic period
(Auracaria) seed plant
Cycad gymnosperm Permian period
(Cycas) seed plant
Horsetail
(Equisetum)
pteridophyte plant Permian period
Animals:
Horseshoe crab arthropod Triassic period
(Limulus)
Fairy shrimp arthropod Silurian period
(Triops)
Lampshell brachiopod Silurian period
(Lingula)
Coelacanth lobe-finned “fish” Cretaceous period
(Latimeria)
Buckland stimulated Lyell’s imagination, not the least by his
unusual behavior. Buckland performed his fieldwork wearing
academic gowns, kept many wild animals at his house,
and ate any animal he could find. Guests might be treated to
baked guinea pig, battered mice, roasted hedgehog, or boiled
sea slug. Although Lyell was to publish works that overturned
Buckland’s theories, Lyell learned from Buckland to
be fearless in choosing direct observation and experience over
tradition. Lyell trained for a law career but, after going on a
geological expedition through Scotland with Buckland, gave
up his legal career for science.
After a geological expedition in Europe, Lyell began
writing the Principles of Geology: An Attempt to Explain
the Former Changes of the Earth’s Surface by Reference to
Causes now in Operation. The first two volumes were published
in 1830 and 1832. These two volumes began a tide of
success, going into a second edition before the third volume
was published in 1833. The Principles went through 11 editions,
each updated and revised with much new information,
during Lyell’s lifetime, and he was working on the 12th edition
when he died. Lyell’s Elements of Geology, focusing
upon fossils and fossilization, first appeared in 1838 and
went through six editions during Lyell’s lifetime. Lyell traveled
extensively, gathering new observations; his visits to the
United States, where he studied the rate of erosion of Niagara
Falls and the rate of sedimentation in the Mississippi Delta,