Populations Flashcards
How can population vary in space and time
Random or clumped
Clustered
Organsims/ individual around a resourse
trade offs
to the process through which a trait increases in fitness at the expense of decreased fitness in another trait.
Active dispersal
is the dispersal of organisms without any assistance. Here, organisms move from their birthplace to another place through their own abilities.
passive dispersal
is a mode of dispersal in which organisms need assistance to move from one place to another place. Seeds of plants mainly disperse by passive dispersal
facilicatated
???
Mark recapture method practice question
A biologist nets 45 largemouth bass from a farm pond, tags their fins, and releases them
unharmed. A week later, she nets 58 bass from the pond, including 26 with tags. Based on the
Lincoln-Peterson index, estimate the number of bass in the pond
Populations can increase in the absense of
selective factors aka predators
Parctice rate of growth questions
demostrate how carrying capacity affects the intrinsic growth rate
changes in varaibles alternating the population
expontential growth
growth whose rate becomes ever more rapid in proportion to the growing total number or size
In their new colombian habitat, hippos are reproducing at an earlier age
rate with increase
K is
Carrying Capacity
The lower the value of r means
The faster the carrying capcity will meet
density dependent
Food availability, predation
Density independent
Natural distaters. Weather
Colombians like having the hippos around and enjoy feeding them food scraps
K- more food larger K
Hippo poo causes algal bloom in their habitat and kills all the aquatic vegetation that they eat
K decrease
Postive density dependent
Allele effect at which occurs primarily when inital population sizes are small. As the population increases the reproduction increases
What is Quorum sensing
Quorum sensing is a way for bacteria to communicate and coordinate their actions based on their population density.
Life tables show
Surviorship as cohorts age in a population
what is Cohorts age
Type 1 surviorship
Where old age is common
Type 2 surviorship
contast risk in all ages
Type 3 surviorship
Most of the individuals die young
Semelparous
Single reproductive event
Iteroparous
Reproduction is repeated
R strategt
Short life span so reproduction needs to happen quickly. With this you can have quick population growth
What kind of surviorship is Density indentpent or r stragiset
Type3
K stragiest
Long life span with high quailty resources . Growth that stablizes
What kind of surviorship is K stragiest
Type 1 or Type 2
Depending on where you live or different areas
Life expectanity is determined.
Think about Covid and the life expenticty after that
It didnt rebound in America
We can detrmine life expecty at a yound age. How? by density dependent vs indepent
Dependent: will determine by the resources you have condition you bound
Independt: is everything out of your control with gun violence, accidents etc
Changes in K
changes in carrying capacity. decrease or increase
