Conservation Biology

What is conservation biology

A biological Science that has a goal of preserving species and habitats in order to prevent extinctions

What is biodiversity

the number of species, genetic variation, ecosystems, and ecosystem-level interactions.

Biodiversity crisis

when the world starts facing a mass extinction

Threats to Biodiversity

Habitat destruction, fragmentation, invasive species global climate change, etc.

Core Conservation Biology topics

Biodiversity, threats to Biodiversity, extinction, Small population dynamics.

Species Diversity

All species in an area and the relative abundance of those species.

What is extinction

There elimination of species or taxonomy group, ( types, rates, vulnerability to extinction).

Genetic Diversity

the genetic variability within a species or population

Ecosystem Diversity

the range of a different ecosystem in an area, and the associations and interactions between them within them. Along with the complexities of the ecological processes and interactions.

How many species are on Earth

about 2 million species are currently described

taxonomic synonym

a species that has multiple scientific names

what inflates species estimates

unknown taxonomic synonyms

Biological species concept

a reproductive isolating mechanism ( through behavior, anatomical, or physiological) that evolves to either prevent fertilization between species ( pre zygotic) or prevents hybrid zygotes from developing ( post zygotic).

Complications with the biological Species concept

The ability / potential ability to interbreed can be difficult to demonstrate

Difficult to apply to organisms that reproduce asexually or with extensive self-fertilization

Does not apply to fossil species

What is a phenotype

the observable characteristics of an individual - hair color, number of teeth, blood chemistry, etc.

cryptic species

species that are very difficult or impossible to tell

apart using phenotypic differences

Divergent evolution

groups with common ancestors becoming increasingly different over time

Ecotype

genetically and phenotypically distinct forms of a species

Polyphenism

changing phenotype in different environmental conditions ( seasonal forms of butterflies)

DNA barcoding

analyzing a region of DNA to determine base pair sequences that can be used for species differentiation and identification.

what is the morphological Species concept

A group of individuals that is morphologically distinct from other groups in some important characteristic

DNA based Species Concept

Several species concepts use similarities in DNA sequences to determine relatedness or shared evolutionary history

environmental DNA (eDNA)

Using mass-sampling techniques to look for new species and assess biodiversity

taxonomic inflation

where everything that can be distinguished becomes its own species

Which species concept is best to use ?

DNA sequences has become the gold standard of identifying and

defining species. Despite obvious limitations, morphological and biological species concepts are still widely used

latitudinal diversity gradientTheory of Island Biogeography

The general increase in species diversity as you move further from the poles and closer to the equator

Theory of Island Biogeography

Therefore, island size and isolation affect species diversity Immigration rate higher for closer islands (distance effect)

Extinction rate lower for larger islands (species-area curve)

Alpha, beta, and Gamma, Diversity

Alpha- Species diversity measured as species richness at

a local scale

Gamma- the number of species in a “landscape”

Beta Diversity- A measure of the difference in species composition between local areas

Simpsons Diversity Index

Gives more weight to common or numerically dominant species

Rare species will not affect the diversity index much or at all

Shannon Diversity Index

Measures the amount of disorder observed in a system

( higher Diversity, higher disorder)

Allele Diversity

Alleles are the basic units of genetic diversity, so genetic diversity can be characterized as the diversity of the alleles present (e.g., in an individual, in a population). An individual can only have 2 alleles for a gene, but more than 2 alleles for a gene can be present in a population

Polymorphic gene

Genes that have more than one allele

homozygous vs heterozygous

homo is the same allele and hetero is two different alleles

factors that influence genetic diversity

Life history patterns, mutation rate, genetic drift

ways to measure genetic diversity

Polymorphism – the proportion of genes in a population that are polymorphic (have multiple alleles)

Mean heterozygosity – the proportion of genes for which the average individual is heterozygous for

What is an ecosystem

An interacting system composed of a biological community plus

the associated physical and chemical environment

Biological community

all the species (plants, animals, etc.) that live in a particular location

Ecosystem diversity relates to ecosystem functionality and stability

Functionality: processes normally associated with ecosystem are functioning well

Stability: ecosystem is relatively constant over time despite disturbances

what is the order of the trophic pyramid ( bottom to top)

Primary producers, primary consumers, secondary consumers, mesopredators, terrestrial consumers, and quaternary consumers.

Bottom-up vs top-down

Bottom-up control: population level and activity of lower trophic levels

(e.g., primary producers) regulate the activity of the ecosystem above (traditional)

Top-down control: population level and activity of higher trophic levels

(e.g., top predators) regulate the overall activity of the ecosystem below

predators 2 types of top-down control

Density mediated control – predators directly reduce the numbers of prey by consuming them

Trait mediated control – predators indirectly reduce the numbers of prey

trophic cascade

When top-down ecosystem control involves three or more trophic levels

mesopredator release

when. population increases in mesopredators due to a decrease in predation from higher order species.

ecosystem engineers

species that alter the physical habitat in important ways

Insurance hypothesis

Increase species diversity leads to increased ecosystem stability

ecosystem services (Millennium Ecosystem Assessment)

Any benefit the the ecosystem provides to society

Provisioning services(food, freshwater, wood for building and fuel)

Regulating( Carbon storage, waste treatment, pollination)

Cultural( Recreation, tourism, Science education)

Supporting( Biodiversity, primary production, water cycle)

Why are we losing biodiversity

Environmental degradation is correlated with affluence and technology

Impact= Population x Affluence x Technology

Cumulative effects

the combined effects on a species from multiple threats

General Major causes of biodiversity loss

Habitat destruction, Pollution, Overexploitation, Invasive species, global climate change.

edge effect

the transition zone between destroyed habitat and natural habitat

Bioaccumulation

when an organism builds up a chemical over time

Biomagnification

when

chemicals increase in concentration as you move to higher trophic levels

R selected vs K selected

R: early sexual maturity, has many offspring with little parental care

K: Reproductive strategy is too have few offspring with high levels of parental care