Why does the fact that he wrote an article on abiogenesis show that it’s an important part of evolutionary theory?
Huxley wrote articles on a wide range of subjects, most of which had nothing or little to do with evolution.
In fact, in this article he no where even discusses evolution (he used the term “evolution”, but not in the sense of “the theory of evolution” or Darwinism).
In fact, interestingly, in this, his inaugural address as president of the BAAS, this “Darwin’s Bulldog” never mentions Darwin - but he does repeatedly mention Pasteur and sing his praises (as he does in many other speeches and publications - he could have been called “Pasteur’s Bulldog”).
“I finished your book yesterday. . . Since I read Von Baer’s Essays nine years ago no work on Natural History Science I have met with has made so great an impression on me & I do most heartily thank you for the great store of new views you have given me. . .
As for your doctrines I am prepared to go to the Stake if requisite. . .
I trust you will not allow yourself to be in any way disgusted or annoyed by the considerable abuse & misrepresentation which unless I greatly mistake is in store for you. . . And as to the curs which will bark and yelp — you must recollect that some of your friends at any rate are endowed with an amount of combativeness which (though you have often & justly rebuked it) may stand you in good stead —
I am sharpening up my claws and beak in readiness
Letter of T. H. Huxley to Charles Darwin, November 23, 1859, regarding the Origin of Species”( www.ucmp.berkeley.edu/history/thuxley.html)
Huxley wrote about a lot things but he is remembered amongst Darwinists for just a few, such as his sea voyage like the one Darwin took and Huxley's well known debate with the Bishop of Oxford on the subject of evolution and his defense of evolution.
1870
“Thomas H. Huxley's Biogenesis and Abiogenesis address is the first clear statement of the basic outlines of modern Darwinian science on the question of the origin of life. The terms “biogenesis” (for life only from pre-existing life) and “abiogenesis” (for life from nonliving materials, what had previously been called spontaneous generation) as used by Huxley in this speech have become the standard terms for discussing the subject of how life originates. The speech offered powerful support for Pasteur's claim to have experimentally disproved spontaneous generation. The speech was also Huxley's attempt to define an orthodox Darwinian position on the question, and attempt to define as “non-Darwinian” all those Darwin supporters who believed that spontaneous generation up to the present day was an essential requirement of evolutionary science. Henry Charlton Bastian was the most prominent leader of that faction of Darwinians, though Huxley was so successful in defining them out of the story that very few people today even realize that there WERE Darwinians who were serious, talented evolutionary scientists, yet also thought abiogenesis was necessary in evolution up to the present day.”
Biogenesis and Abiogenesis
James Strick. 1999.Darwinism and the Origin of Life: the Role of H.C. Bastian in the British Spontaneous Generation Debates, 1868-1873. Journal of the History of Biology, 32:1-42
www.asm.org/membership/index.asp?bid=16731 But I won't do all your research for you.