32_Human_pop_growth_Life_history

32_Human_pop_growth_Life_history - Human Population Growth...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Human Population Growth Analyzing Life History l f Today s questions: Today's questions: I. I What will the human population be over the What will the human population be over the course of your lifetime? II. How do fitness tradeoffs affect the evolution of II How do fitness trade offs affect the evolution of life histories? I. What will the human population be when you're in your early 60s? Current population ~7.0 billion 2010 update: fertility 2100 pop'n (avg. #kids/female) (billions) (avg. #kids/female) (billions) Current, continued ~2.6 "High" projection to ~2.5 "Medium" projection to ~2.0 "Low" projection to ~1.5 What is the replacement rate? 1. Why isn't the replacement rate 2.0? y p 2. Why is the replacement rate higher in developing versus industrialized nations? industrialized nations? Trends in growth rate and fertility: Growth rate/year Avg. fertility 196570: 2.04% 1965 70: 2 04% 199095: 1.46% 1990 95: 1 46% 200005: 1.2% 2000 05: 1 2% We're currently adding ~ million people/year ... We're currently adding ~ million people/year % in developing countries What conditions contribute to declining fertility rates, h d b d l f l and why? Consider: Income Lifespan/child mortality Women's rights (including education and access to birth control) Religious beliefs Religious beliefs The role of emigration/immigration Will all of the people born in developing countries stay in developing countries? p g 2004 Pew Hispanic Center survey in Mexico: If you could, 2004 P Hi i C t i M i If ld would you emigrate to the United States? In terms of biological impact of humans, the two key factors are: 1. Number of people (population size) 2. Resources used per person Currently, what is the relationship between these two factors? II. How do fitness tradeoffs affect the evolution of life histories? histories? Experiment (in text) on sideblotched lizards: 1. Remove yolk from eggs 2. Remove all but 23 eggs 3. Sham operation In terms of maternal investment in offspring, what does each treatment group represent? 1. What was the relationship between clutch size and egg size? 2. What was the relationship between egg size and offspring survival? offspring survival? 3. Did mothers that laid large eggs or small eggs have optimal fitness? ...
View Full Document

Ask a homework question - tutors are online