Complex sentence: Thomas Henry Huxley (4 May 1825--29 June 1895) was an English biologist (comparative anatomist), known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.
Split into simpler sentences: Thomas Henry Huxley (4 May 1825--29 June 1895) was an English biologist specialising in comparative anatomy. He is known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.