sci 11 population dynamics

• Organism

  Individual form of life
• Species

  Genetically similar organisms that reproduce
• Population

  All members of the same species in a given area
• Biotic community


  An assemblage of populations that function as an integrative unit through coevolved metabolic transformations in a habitat
• Properties of Population

  • Size
  • Density
  • Dispersion
• Population Size

  Total number of individuals in a population
• Population Density

  Number of individuals per unit area or volume
• Dispersion


  Spacing of organisms relative to each other
• Patterns of Dispersion

  • Random
  • Regular
  • Random Clumped
  • Regular Clumped
• Random Dispersion


  • Occurs when environment is very uniform
  • No tendency to aggregate
  • Many factors acting on the population
• Regular Dispersion

  • Uniform dispersion
  • Occurs when competition between individuals is severe
  • Even spacing
  • Few major factors dominating
• Clumped Dispersion

  • Most common pattern
  • Strong tendency for organisms to aggregate
  • Individuals form groups of a certain size
• Random Clumped Dispersion

  • Clumped in a random pattern
• Regular Clumped Dispersion

  • Clumped in a regular pattern with large unoccupied spaces
• Lincoln Index

  Capturing and marking some fraction of the total population and using this fraction to estimate total population density
• Assumptions for Lincoln Index

  • Marking technique has no negative effect on mortality
  • Marked individuals released at original site and allowed to mix
  • Marking does not affect probability of recapture
  • Marks not lost or overlooked
  • No significant immigration/emigration
  • No significant mortality/natality
• Minimum Known Alive

  Mark-recapture method where total number of individuals observed is used as an index
• Other Methods for Estimating Population Density

  • Total counts
  • Quadrat or transect sampling
  • Removal sampling
  • Plotless method
  • Importance percentage value
• The ratio of marked to unmarked individuals allows scientists to calculate total population size
• The larger the population, the lower the percentage of tagged organisms that will be recaptured
• Natality


  Number of individuals added to the population through reproduction
• Mortality


  Rate at which individuals are lost by death
• Immigration

  Movement of individuals into a population
• Emigration

  Movement of individuals out of a population
• Types of Natality

  • Maximum natality
  • Ecological natality
• The Philippines had a total population of 109,035,343 persons in 2020

  
• The household population comprised 99.7% or 108,667,043 persons in 2020
• 50.6% of the 108.67 million household population were males, 49.4% were females in 2020
• 30.7% of the population were under 15 years old, 63.9% were 15-64 years old, 5.4% were 65+ years old in 2020
• The sex ratio was 103 males per 100 females in 2020
• The median age was 25.3 years in 2020
• 63.4% of the household population was of voting age (18+) in 2020
• Senior citizens (60+) made up 8.5% of the household population in 2020
• There were more female (55.5%) than male (44.5%) senior citizens in 2020
• There were 531,280 registered deaths in the Philippines in 2013
• The death sex ratio was 1 female to 1.34 males in 2013
• 99.1% of fetal deaths were attended by qualified medical professionals in 2013
• Ecological Mortality

  Loss of individuals under a given environmental condition
• Minimum Mortality

  Minimum loss under ideal or non-limiting conditions
• Sex Ratio

  Relative numbers of males and females