This is a podcast from the archives of the BBC Reith Lectures.

This lecture in the series Wilderness and Plenty, given by Sir Frank Fraser Darling,

was originally broadcast in 1969.

In my first lecture, I said that although man is not yet Lord of Creation,

he's undoubtedly the dominant species on our planet. Moreover, he's such a

complex creature that he's constantly challenging and altering his environment. As soon as he became

man, and we didn't bother just when it was, he began to alter the face of the natural world as it had been until

then. While he remained a hunter food gatherer, he was little more than another indigenous

animal, but as soon as he burned wood to keep warm, he was consuming it in a different way from

natural decay, with different consequences.

When he used fires and aid to driving wild animals into places where he could kill them easier,

and by burning bush could encourage hoofed animals to graze on the young grass which followed,

he'd begun his ceaseless attrition of the natural wilderness. He had begun his ceaseless attrition of the natural wilderness.

At first, men were presumably few,

and they evolved on an earth that had already been amassing biological wealth

for millions of years.

Their burning of habitat for hunting was, of course, a prodigious expenditure

of organic matter for momentary expedience. This led to impoverishment of the broad spectrum of species

of plants. Biological productivity and ecological wealth rest on the wide variety of species,

which means flexibility and unconscious cooperation within the whole ecosystem.

When man alters natural ecosystems by design or ignorance, they're usually simplified or made less complete,

and they lose something of their holistic quality of resistance to invasion by foreign species.

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