Q 5.1 1. What factors have caused changes in human population growth rates during the past 100,000 years? 5.2 3. What factors account for the global decrease in infant mortality rates and increase in life expectancy over the past 50 years? 5.3 2. Why is forecasting human population growth more difficult than forecasting population growth in other animals? 5.4 3. The world’s biocapacity is estimated by some to have declined by as much as 12% between 1995 and 2005. What factors may have contributed to this decline? 5.5 1. What was the neo-Malthusian movement and why was it important?