cons bio MEGA SET exam 1

keystone species

sea otter - an organism that helps define an entire ecosystem

indicator species

spotted owl - any species (plant, animal, bird, insect or even bacteria) that reflects the condition of its environment

umbrella species

bengal tiger - a species that is chosen to represent the conservation of other species in its habitat

flagship species

panda - a well-known species that is chosen to represent a habitat, issue, or environmental cause and to encourage support for its conservation

vulnerable species

hawaiian silversword - a species that is at a high risk of extinction

economically important species

chinook salmon - those that contribute to the wealth and stability of a society through their production of food, materials, or services

suppose you are in charge of managing a species but you need to better understand how well it is doing first. what info do you need to help you make your decision?

• population count

• look @ past numbers to determine if an event occurred to determine how regrowth was affected

• habitat

• food sources

• reproduction rate

• demographic

how does PVA help you make better decisions about conservation?

PVA is used to take foundational strategies and ideas about conservation and align them perfectly with the needs of the population

what are problems facing populations?

• habitat loss and fragmentation

• environmental disasters

• genetic disorders

• lack of resources

• growth/mortality rate

what are some strategies to protect populations?

• provide resources like food and shelter

• restore degraded habitats

• limit human interaction and impact

• let nature restore balance to itself

from an ethical scientific standpoint rank the importance of conserving the following species. a) a rare species b) an endangered species c) a common species with a very small population . which would be most important to protect, which would be the least and why?

B, A, and C. From an ethical and scientific standpoint, the most important species to protect is the endangered species, as it faces an immediate risk of extinction and its loss could have severe ecological consequences. Next in priority is the rare species, which, while not necessarily endangered, has a naturally low population and may play a crucial role in maintaining biodiversity and ecosystem stability. The least urgent to protect is the common species with a small population, as it likely has stable populations elsewhere and is not yet at critical risk.

small populations face a lot of challenges. what criteria would you use to decide to intervene?

when the population can no longer sustain a reproduction rate that keeps the species afloat

3 levels of biodiversity

species, genetic, community

goal of cons bio

to conserve biodiversity

species diversity

• species are focus of most conservation efforts

• usually morphological or genetically distinct ability to interbreed

• species are not fixed entities

speciation

new species develop in response to:

• interactions with other species

• environmental/climate change

• isolation

• extinction - opp cost

genetic diversity

• variation in genes allow adaptation to changing environments

• small and/or captive populations most vulnerable

  • naturally

  • due to fragmentation

  • from migration

3 levels of genetic diversity

• variation w/in individuals

• differences among individuals w/in a population

• differences among populations

community/ecosystem diversity

• communities: groups of interacting organisms in the same area

• ecosystems: biological communities association w/ the physical environment

effective population size (Nsube)

link b/t size of population and genetic diversity

• effective population size

founder effect

• diversity lost when population separates

demographic bottleneck

• occurs when population experiences severe reduction in size

• genetic diversity diff then before event

• a few individuals contribute to next gen

• minor effects if population recovers in size in gen or two

genetic drift

• random change in gene frequencies

  • unpredictable

• rare alleles may be lost

• reduced ability to adapt to future conditions

• rate of loss is a function of population size

inbreeding depression

mating of closely related individuals

may cause reduction in:

• fecundity

• offspring size

• growth

• survival

effects of low heterozygosity

• expression of deleterious alleles

  • his displaysia, european royals

• lower fitness

  • scarlet gila

grow population bigger

• all need food, shelter, and to reproduce

lion - bottleneck

• isolated

• lack of immigration

• susceptible to disease

• reduced genetic variation

northern elephant seal

hunted until population expanded rapidly

which is least useful criteria to conservation action?

low genetic diversity

3 genetic issues

• drift

• inbreeding

• gene flow

abundance =

(birth + immigration) - (death + emmigration)

growth rate

how many now/how many in the past

if growth rate over 1

expanding

= to 1

not changing

below 1

declining

limits to growth

• biotic

• abiotic

Conservation Biology

protection of biodiversity through understanding and problem solving

Biological Diversity

Variety of life on earth

What are the different levels of bio diversity?

Species, genetic and community

Species

Usually genetically direct with the ability to interbreed

Species are not fixed entities

Speciation

Formation of new species

What do new species develop in response to?

interactions with other species

environmental and climate change

isolation

extinction (needed for speciation)

How many species are there?

1.5 million described

Genetic Diversity

Variation in genes allows adaptation to changing environments

What are the three levels of genetic diversity?

Variation with individuals

Differences among individuals in a population

Differences among populations

Communities

Groups of interacting organisms

in the same area

Ecosystem

biological communities associations with physical environment

Where is diversity found?

Tropical rainforest

Tropical deciduous forest

Temperature Shrublands

Coral Reefs

Deep Sea

Islands

What does variation in genetic diversity allow?

adaptation to change environments

What is the founder effect?

A change in allele frequencies as a result of the migration of a small subgroup of a population.

What causes the founder effect?

The migration of a small subgroup of a population.

What is a demographic bottleneck?

A population founded when just a few members of a species survive a catastrophic event.

What can cause a demographic bottleneck?

A catastrophic event or colonization of new habitat geographically isolated from other members of the same species.

What is genetic drift?

A random change in gene frequencies.

What can happen to rare alleles due to genetic drift?

Rare alleles may be lost from the population.

How does genetic drift affect a population's ability to adapt?

It reduces the ability to adapt to future conditions.

What is the rate of loss of alleles due to genetic drift a function of?

Population size.

Inbreeding Depression

Mating of closely related individuals

What might inbreeding depression cause a reduction of?

fecundity

offspring size

growth

Survival

fecundity

The potential reproductive capacity of a female

Lion bottle neck

Isolation

Lack of immigration

Susceptible to disease

Reduced genetic variability

What was the population of Northern elephant seals reduced to by the late 1800s?

Only 20 left

What was the effective population size of Northern elephant seals?e

12 to 14

What did Le Boeuf find regarding genetic variation in Northern elephant seals?

No variation at 7 loci

What happened to the Northern elephant seal population after being left alone to breed?

The population expanded very rapidly to more than 40,000

Population Growth

With limitless resources populations grow exponentially

Biotic limits on population growth

food, predators, competitors, diseases, mating

Biotic factors

living parts of an ecosystem

Abiotic limits on population growth

light, shelter, disturbance

Abiotic factors

Nonliving components of environment.

Density Dependence

growth rate is a function of population size

Demographic stochasticity

Random variation in fates of individuals.

What is stochasticity dependent on?

population size (small populations are the most vulnerable).

What is environmental stochasticity?

Random variation due to environmental factors.

What types of factors contribute to environmental stochasticity?

Abiotic and biotic factors.

Give examples of abiotic factors that can cause environmental stochasticity.

Rainfall and temperature.

Give examples of biotic factors that can cause environmental stochasticity.

Predators and prey.

Abundance

(birth + immigration) - (death + emigration)

Growth Rate

Nt + 1 / Nt

Example:

Nt = 1,000

Nt + 1 = 1,500