ENVS 200 CHAP 13 Flashcards
What is conservation?
It is the name given to various actions we can take to slow/reverse the loss of species and biodiversity
What is biodiversity?
It is equivalent to species richness as it is the number of species present in a defined area. It can range from looking at genetic to community diversity.
3 nested levels are: ecosystem>species>genes
What is restoration?
It is conservation in a broader sense as it’s goal is to reverse a past failure to conserve.
ex. reintroducing a species to an area where they had previously gone locally extinct, usually due to anthropogenic habitat destruction
What is demographic uncertainty/stochasity?
It is the random variations in variables that are super important to the fate of a pop, like: the number of individuals born male or female; the number that die/reproduce in a year; and the genetic qualities of survival/reproductive capacity.
ex. a year where all females were born could be catastrophic to that pop (easier to get skewed gender ratio in smaller pops)
What is environmental uncertainty/stochasity?
It is the unpredictable changes in environmental factors, like disasters (ex. high magnitude earthquake) and minor events (ex. avg temp variations) that can also seal the fate of a pop.
ex. adverse conditions could be fatal - small pops have less variable availability to survive
What are alleles?
They are a pair of genes that occur at the same location on a chromosome
What are homozygous alleles?
It is when the alleles provided by both the mother and father are identical. This occurs when individuals breed with close relatives, causing offspring to be more likely to receive harmful genes.
What are heterozygous alleles?
It is when there is one dominant and one recessive allele (different genes from both parents make up a pair), is much healthier, and is most often found in larger pops
Inbreeding depression
Close breeding with relatives causing offspring to receive harmful genes
This often results in a loss of genetic variation within small pops.
ex. reduction in fertility, survival, and growth rates
What is overexploitation?
It is a pop that is harvested at an unsustainable rate, given the natural mortality and reproduction
What is an introduced species?
They are species accidentally, intentionally (often unaware of potential consequences) introduced by humans that can cause invasions of exotic species. Sometimes they can be assimilated into communities without harm, but some are responsible for dramatic changes and they can be invasive.
What is an extinction vortex?
It is a pop that has been reduced to a small size and can lead to increased inbreeding, leading to reduced survivorship/fecundity and causing the pop to continually become smaller until it is extinct
What is the minimum viable population (MVP)?
The numbers vary, but the MVP value is typically determined by at least a 95% probability of species persistence for 100 yrs
What is population viability analyses (PVAs)?
It provides an alternative, specific way of gauging viability as it estimates survivorship & reproductive rates in age-structured pops and simulates variations to represent impacts of environmental disturbances, like varied disaster frequencies and intensities.
What is a charismatic species?
They are animals that are easy to sell to the public because it is in trouble/of importance and people care about it.
ex. polar bear
