Trilobites
Trilobites (三葉蟲) are an extinct group of invertebrates with a hard
shell and jointed-legs. They are probably the most common fossils
of the Palaeozoic Era (古生代) (about 545–250 million years ago). Trilobites
were very diverse — over 15 000 species are known. The largest trilobite
discovered measures 72 cm in length, while the size of most trilobites
was between 3 to 10 cm. Some trilobites were burrowing animals,
while others could swim and crawl on the sea floor. They could roll
into a ball for protection. Since trilobites evolved quickly and
were widely distributed, scientists use them in comparing the ages
of rock layers in different parts of the world.
A fossil of a trilobite
Alfred Russel
Wallace
Alfred Russel Wallace (華萊士) (1823–1913) was a British natural scientist.
He went to Amazon (亞馬遜) and the South East Asia to collect animal
and plant specimens for his own research and for sale. After returning
from the trips, Wallace wrote an account of his travels and observations,
including two scientific articles on the origin of new species.
Independently, he arrived at a theory of natural selection to explain
evolution, similar to that proposed by Charles Darwin. Wallace later
sent his article outlining his ideas on evolution to Darwin, who
had not yet published his. Together they presented a paper to the
Linnean Society, a biological society, in 1858 and the theories
proposed by both of them were published in the same year.
Biological specimens collected from The Brazilian Amazon Rainforest
helped Wallace in formulating his theory of natural selection
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