All human societies go through fads in which they temporarily either adopt practices of little use or else abandon practices of considerable use.

Measles and TB evolved from diseases of our cattle, influenza from a disease of pigs, and smallpox possibly from a disease of camels. The Americas had very few native domesticated animal species from which humans could acquire such diseases.

Thousands of years ago, humans domesticated every possible large wild mammal species fulfilling all those criteria and worth domesticating, with the result that there have been no valuable additions of domestic animals in recent times, despite the efforts of modern science.

Federal elections happen every two years in this country. Presidential elections every four years. And four years just isn't long enough to dismantle all the environmental laws we've got in this country.

Australia is the most isolated continent.

History as well as life itself is complicated -- neither life nor history is an enterprise for those who seek simplicity and consistency.

I personally am not conscious of my accent.