Population Ecology Flashcards
What is the study of interaction between organism and their environment (all components) ?
Ecology (Environmental Scientist, Behaviorist, and Water Chemist).
Name some abiotic components:
Light, water, wind, nutrients, pH, etc.
Name some biotic components:
Other organisms as competitors, predators, parasites, prey, hosts, and mutualists
Ecology seeks to explain the ________ and _______ of organisms.
Distribution
Abundances
Why did Cattle egrets migrate form Africa?
Natural Expansion
What are the different levels of ecological studies? (6)
Organismal Ecology (Behavior), Population Ecology (Single Species @ a population level), Community ecology (Multiple Species interactions), Ecosystem Ecology, Landscape and Global Ecology (Environmental Species), and Biodiversity (Species going extinct)
The 3 ways to describe a population?
Growing, Shrinking, or staying the same.
Insect population tend to ?
Fluctuate
Density and Dispersion are other forms of describing ______?
Population
Dispersion in a population is categorized by ? (3)
Clumped (Fish) , Uniform (Territory| Penguin), and Random (Grass patches)
Dispersion tell how an individual is distributed in space.
Vital Statistic are used to understand what in a population? (Demography)
Why its growing or not.
What are the 4 vital Statistics?
Age Structure (No. of individuals at each age), Birth Rates (Average number of births through age classes), Death Rates (deaths/ person at each age), and Generation time (average time between the birth of a female and the birth of her offspring)
Generation Time in a vital statistic is effected by what?
Average time between the birth of a female and birth of her offspring.
In demography,____ ______ account for births and deaths to get _________
Life Tables, Generations
Life tables calculate ?
Life expectancies, and rate of increase (Insurance rates)
A cohort is used to?
Make a lifetable and to follow individuals born at the same time until deaths.
4 centuries ago, ___ _____, created one of the first Life Tables
John Graunt
In J. Graunts life table, how many individuals had died?
60% by age 16
In a life table Proportion, (lx) is what?
No. Alive
In a life table, Mx represents?
Offspring of female
The net replacement rate= the sum of (__) times (__) for each age class, :
lx, Mx
If the net replacement rate for each age classes equals 1 then,
The population is stable, neither growing or shrinking
If the net replacement rate for each age classes equals <1 then the population is?
Shrinking
In some species we can calculate R0 for different Phenotypes (or genotypes) to measure?
Fitness
What data can be used for survivorship curves/
Life table datas
In the graph for Survivorship curves , the log scale (y-axis) is ?
Per Capital
In type II survivorship curves, 50% of all ages have the ____probability of _____. This looks like a downward slope only if the Number of survivors are ______ and age is changed to _______ ___ ____
Same, dying
Log Scale, Percentage of Maximum life span.
What are the three types of Survivorship Curves and their meanings?
Type I: Little juvenile mortality, and most likely parental care in animals.
Type II: Age independent morality
Type III: Mortality is high in juvenile age.
The traits that affect a populations schedule of births & deaths are called ? and what do they have a strong effect on?
Life-history traits, Fitness
Life-History traits account for ______?
Population Vital Statistics:
Life-Span,
Age of first reproduction, Clutch or litter size, Number of reproductive bouts
What are the two reproduction variations and what do they mean?
Semelplarity: Have sex once, then die. (This is favored) SALMON, CENTURY PLANT
Iteroparity: Repeated reproduction. OAK TREES, HUMANS
In iteroparity, what are the negative effects?
Raising too many off spring
Current reproduction and Survival or Future reproduction are known as what?
Trade offs
What is the trade off of Spring and Summer ______?
Spring do not have predators to worry about and therefore gain the ability to lay many eggs, but Summer respond by having a sharp head and tail spin for defense against predators.
How can we retrieve population size at any given time?
By modeling a populations capacity to grow. Exponential Model
How do we keep the Exponential Model a set limit?
By inserting the Logistic Growth Model (K-N)/K
In the logistic growth model, K is presented as what?
Carrying Capacity or Maximum population size that can be supported by available resources
In the logistic growth model, N can not surpass what variable?
K
If in logistic growth, N exceeds K, then what happens to the graph?
It becomes negative
What bounds/regulates population? (5)
Density-dependent factors (Mortality Factors): Food & Water resources Predation Vector-Transmitted disease Territorial Behavior Toxic Wastes
Explain Positively density factors
When population gets higher the more deaths meaning its keeps population at a higher level (Mortality goes up)
and when population is lower, the mortality goes down.
What does it mean when the line in a Density-dependent factor graph goes above the upper bound?
The mortality rate is low, but the population is high
Hoe many humans are there on the earth right now?
Roughly 8 mil
What shows exponential growth?
Doubling times
Are we slowing down or increasing population as a human species/
Slowing down
How is exponential growth fueled?
Drop in death rates
Drop in death rates in human is due to what?
Better nutrition, medical care, lowered infant mortality leading to more newborns that can have their own offspring
Are birth rates now starting to drop ?
Yes
Growth rates are seen in _ year intervals.
5
Why do we not know the earths carrying capacity?
Because K changes with agriculture efficiency, food habits, efficiency of space use… etc.
When do projections show the human population leveling off?
50 years
