The Science Book

173

See also: Mary Anning 116–17 ■ Charles Darwin 142–49

A CENTURY OF PROGRESS

Huxley came to believe that there
was an evolutionary link between
birds and dinosaurs, but he did not
imagine a common ancestor would
ever be found. What mattered to
him were the very clear similarities.
Like reptiles, birds have scales—
feathers are simply developments
of scales—and they lay eggs. They
also have a host of similarities in
bone structure.
Nevertheless, the link between
dinosaurs and birds remained
disputed for another century. Then,
in the 1960s, studies of the sleek,
agile raptor Deinonychus (a relative
of Veloci raptor) began finally to
convince many paleontologists
of the link between birds and these
microraptors (small predatory
dinosaurs). In recent years, a host
of finds of fossils of ancient birds
and birdlike dinosaurs in China has
strengthened the link—including
the discovery in 2005 of a small

dinosaur with feathered legs,

Pedopenna. Also that year, a

groundbreaking study of DNA

extracted from the fossilized soft

tissue of a Tyrannosaurus rex

showed that dinosaurs are

genetically more similar to birds

than to other reptiles. ■

Detailed studies of fossils of small dinosaurs show many

features in common with birds.

Birdlike Archaeopteryx fossils have teeth, like dinosaurs.

Thomas Henry Huxley

Born in London, Huxley

became an apprentice doctor

at 13 years old. At 21, he was

a surgeon aboard a Royal

Navy ship assigned to chart

the seas around Australia

and New Guinea. During

the voyage, he wrote papers

on the marine invertebrates

he collected, and these so

impressed the Royal Society

that he was elected a fellow

in 1851. On his return in 1854,

Huxley became a lecturer in

natural history at the Royal

School of Mines.

After meeting Charles

Darwin in 1856, Huxley

became a strong advocate of

Darwin’s theories. In a debate

on evolution held in 1860,

Huxley won the day against

Samuel Wilberforce, Bishop of

Oxford, who argued for God’s

creation. Along with his work

showing similarities between

birds and dinosaurs, he

gathered evidence on the

subject of human origins.

Key works

1858 The Theory of the

Vertebrate Skull

1863 Evidence as to Man’s

Place in Nature

1880 The Coming of Age

of the Origin of Species

There is an evolutionary link between

birds and dinosaurs.

The similarities between the anatomy of birds and dinosaurs

are too great to be a coincidence.

Birds are essentially similar to

Reptiles...these animals may

be said to be merely an

extremely modified and

aberrant Reptilian type.

Thomas Henry Huxley