1. Unit 5
ECOLOGY

2. Chapter 19
populations

3. Section 1 understanding populations

4. Section 1

5. Understanding populations
2003: human pop ________________
(__________________________________________)
2016: human pop _____________
Caused a _________in many other populations

7. Properties of populations
________________________________________________________________________________
When studying populations:
_______________________________________
________________________________________

8. Population size
________________________________________________________________________________
Small area, sessile orgs, can just count
Can be difficult to measure if…
________________________________________
Scientists must estimate

9. Population size Example: population size of oak trees in 10km2
Easiest way:
Count 1km2
Estimate the value
__________________________________________

10. Population size The above mentioned method can be used on animals
Scientist must assume distribution is the same everywhere
Leaves room for error

11. Population density ________________________________________
________________________________________________________________________________
Some countries may be more densely populated than others

12. Facts about thailand
The population of Thailand is estimated at _____________________ as of July
Thailand's population is equivalent to ______of the total world population.
Thailand ranks number _______ in the list of countries by population.
The population density in Thailand is _______________________________________

13. Dispersion
________________________________________________________________________________
Clumped distribution: _____________________ _______________________________________
Uniform distribution: ______________________ ________________________________________
Random distribution: _____________________ ________________________________________

14. dispersion

15. dispersion Clumped distribution Uniform distribution Random dispersion
____________________________________________________________________________________
__________________________________________
Uniform distribution
Random dispersion

16. Population dynamics Change in size and composition over time
Birth rate is important
Death rate is important (______________rate)
Life expectancy is important
__________________________________________
Thailand 2012: LE = __________________________
USA 2012 LE: _______________________________

17. Age structure ________________________________________
Presented in graphs
In humans: old indiv do not reproduce
If human pop has high % of young indiv, potential for rapid growth is high

18. Age structure
Which country will have a bigger pop growth in the future?

19. Pattern of mortality
Mortality tend to follow one of three curves on a graph
_______________________________________

20. Pattern of mortality Type 1: _________________________________
__________________________________________
Type 2: _________________________________
Type 3: _________________________________

21. Homework section 1

22. Section 2 measuring populations

23. Section 2

24. Measuring populations
How do populations grow?
What factors limit population growth?

25. Population growth rate
Demographers: __________________________ _______________________________________
Growth rate: ____________________________ ______________________________________
Depends on four processes:
Immigration: ________________________________
______________
_____________________________________________
Emigration: _________________________________
________________
________________________________________________

26. Population size Large pop are divided into groups of _________
Expressed per capita (____________________)
Example:
52 births, 14 deaths per 1000 per year
Birth rate: _________________________________
Death rate: ________________________________
Growth rate = ___________________________
_________________________growth per capita

27. Population size Finding the number of new indiv in a year:
__________________________________________
If pop is : ____________________________
Positive number: _____________________________
Negative number: ____________________________

28. The exponential model
Pattern of increase in number due to _______________________________________
Pop will add a larger number of indiv with each generation
____________________________
________________________________________________________________________________

29. The exponential model

30. Applying the exponential model
Exponential model matches observed real life patterns under certain conditions and for limited periods of time
________________________________________
Pop cannot grow indefinitely
__________________________________________
These factors are called _____________________

31. Applying the exponential model
As pop grows, competition for resources start, __________________________________
__________________________________
Birth rate __________, death rate __________

32. The logistic model Birth rates & death rates are NOT constant
Logistic model builds on exponential model, but includes __________________: _____________ ________________________________________
Graph shape is _______________________

33. The logistic model
Small pop, birth rates _____, death rates ____, pop grows at ________________________
As pop size reaches Carrying Capacity, pop growth slows
When pop size reaches Carrying capacity, growth ____________
Logistic growth
Assuming Carrying capacity is ______________

34. The logistic model

35. Population regulation
Limiting factors that control pop size:
Density-independent factors:
________________________________________
_________________________________________
Density-dependent factors:
____________________, (__________________________)
Triggered by ________________________
________________________________________________________________________________________________

36. Population fluctuations
All pops fluctuate (rise and fall irregularly) in size
Some are linked to environmental changes, some are not (harder to explain)

37. Population fluctuations

38. Perils of small populations
Perils: serious & immediate danger
Rapid growth of human pop has reduced other pops
Small pops are ____________________________
Environmental disturbances can kill the ________
Likelihood of inbreeding (___________________) increases: makes them less likely to adapt to environmental changes due to decreased _________________

39. Perils of small populations

40. Homework section 2

41. Section 3 human population growth

42. Section 3

43. Human populations growth

44. History of population growth
Homo sapiens = __________________
From y.a. until y.a. human pop grew very slowly
Humans lived in small, nomadic (___________ _________________) groups, hunted and gathered food = __________________________
Few societies left today
Low pop growth rate due to _______________ among infants and children (______________________________________)

45. The development of agriculture
ya humans started domesticating animals & cultivate food
Domesticate: _______________________________ ___________________________________________
Cultivate: ___________________________________ ___________________________________________
This change in lifestyle is called _____________________________________

46. Agricultural revolution
Lead to many changes
________________________________________
Resulting in human pop growing faster
10 000ya: ______________________________
2 000ya: ________________________________

47. The population explosion

48. The population explosion
bubonic plague killed _____ of pop
Human pop growth accelerated after 1650, ____________________, better _________and _______, ____________, ______________, ______________________________
1650: ________, 1800: ______, 1930: _______

49. The population explosion
Mortality rates dropped again after WW2, improvements in _________________in poorer countries
In just 27 years ( ) the human pop grew from ___________________

50. Population growth today
20% of world pop live in ___________countries (modern, industrialized countries)
US, Japan, Germany, France, UK, Australia, Canada, Russia
Pop growth is very low: _____________________
80% of world pop live in ___________countries
Most Asian countries, Central America, South America, Africa
Pop growing faster: _________________________

51. Demographic transition
Delete this slide for students, only for teacher

52. Demographic transition

53. Homework section 3