why conserve biodiversity?
what is conservation genetics?
→ diversity is been discovered; morphology, phenotype etc. If you mapped it by environments you see
similar between groups. Life is everywhere
→ we are losing biodiversity in increasing phase : so we are going to conserve
* extinction are part of life
- 40 miljoen species alive today
- what ever lived on earth 40 million
- 1/1000 is still in live >99% is extinct
why should we bother conservation now a days?
- extinction is going to fast
- to keep ecosystems running > biodiversity is important
- we are the problem!
- individual species are not important they are interchangeable (argument)
- value biodiversity per se debatable (argument)
- as long as not all species die out, there is no serious problem (argument)
is it a bad problem? What do you wanna do to conserve? Cost involved better to other subjects as
illness or poverty?
* what makes biodiversity special? why conserve?
- biodiversity is important as it defines nature
- it is nature our natural environment that we live in
* bio-resources (do we need to live on planet)
- ecosystem services (trees produce oxygen)
samen met de bovenste > biodiversity is useful andor has ecological value!
ethics/ aesthetics
not less than the other two
Biodiversity is useful and or has economic value
*ethics and aesthetics
- it is beautiful unique and needs to be preserved
- human like to collect
- we have a moral obligation to study live before it gets lost forever
- Human do not have the right to drive others to extinction
* bio resources
- nature provides us with essential resources from wood to pharmaceuticals
- gone is gone very many unique compounds may get lost with extinction
- it is important for sustaining food supply: natural genetic variation drives animal and crop breeding to -
sustain the human population
,* ecosystem services
- essential biological function benefitting mankind such as oxygen production nutrient cycles water
purification
- loss of diversity in ecosystems may cause ecosystems to collapse
- where would it collapse~
- loss of diversity makes us vulnerable (monocultures and pathogen outbreak)
* speciation and extinction
live on earth characterized by repeated events of speciation and extinction
specialisation:
study the evolutionary processes that shape genetic variation within and between populations and
species
extinction:
study genetic, demographie and stochastic processes that causes extinction
conservation genetics:
motivated by the need to reduce current rates of extinction and to preserve biodiversity
* The dynamics of extinction
there are dynamics in extinctions > one period when a lot of extinctions take place
the 5 important mass extinctions: mostly together with nature disaster
- the late ordovician
- the late devonian
- at the end of the permian period
- the late triassic
- at the cretaceous-tertiary boundary
individuals struggle for existence; survival of the fittest
demographic stochasticity
population go extinct, which can cause species to go extinct
→ (note: extinction also creates opportunities for speciation due to empty niches (dinos>mammals)
* sixth extinction:
problem now is the speed of extinction due to human impact
realy good name; we are losing species
lots of extinctions happened on islands > small area
we have four levels of extinction
- critically endangered
- endangered
- vulnerable
- low risk
* primary causes of extinction:
- the rapid growth of human population (disturbance)
- habitat loss (destruction and fragmentation)(the smaller the pop. the more readily a population goes
extinct)
,- introduction species
- Overexploitation and overkill
- Disturbance
- Pollution
* Reduction in population size –stochastic effects
Environmental stochasticity – rainfall, food supply, catastrophes
Demographic stochasticity – variation in birth/dead rates, sex ratios
Genetic stochasticity – effects in small populations
Loss of genetic variation – loss of adaptive potential
Inbreeding depression – deleterious effects of recessive mutations
→ correlation between population size and time off extinction
* extinction vortex
small population > inbreeding + genetic drift>loss off genetic variability> reduction offitness and
adaptability of population > lower reproduction + higher mortaility > smaller popultation
main focus > loss of genetic variability !
* who is at risk ?
IUCN, we use level of extinction because everyone knows the same thing. One of five abcde than it
belongs to that group (see table )
- critically endangered
- endangered
- vulnerable
- low risk
> but other systems are also used
> species differ in potential risk
,* conservation genetics
uses genetic theory and techniques to reduce riskk of extinction in threatened species!
, College 2 genetic diversity
* the role of genetics in conservation biology
- genetic tools used to infer important parameters in populations of endangered species. ((quantifying
genetic diversity, population structure, breeding system, migration patterns et cetera)
- Genetics ad an object of study inferring the consequences of genetic erosion for population persistence
(loss of variation and fitness, inbreeding depression adaptive potential, extinction probabilities)
* why is genetic diversity important?
genetic diversity is needed for populations to adapt to their environment
g.d. is directly related to the adaptive potential of populations
Especially relevant in the face of changing environments (human impact)
low genetic diversity is also associated with reduced reproductive fitness
* rate of evolutionary changes
Evolutionary potential in changing environment. Co adapting only possible when genetic variation is
present, denk aan de konijnen voorbeeld
* low genetic diversity low fitness
Reduction in heterozygosity might decrease fitness and increase extinction risk
* what is genetic diversity
g.d. is variety of alleles and genoty pepresent in the group understudy
refers to population species or group species
genetic diversity can refer to DNA sequence, gene copy number…\
, genotype is unique but if you look at a locus, allel can be the same (blue eyes)
measures of genetic diversity:
* Hardy weinberg
the sexual shuffling of genes alone cannot alter the overall genetic makeup of a population
Applies when:
- organism is diploid
- reproduction is sexual
- generations do not overlap
- allele freqs. are equal in female and male
- mating is random
- population size is (very) large
- no migration
- no mutation
- no selection
I assume HW equilibrium! schrijf dat er schrijven
Hardy-Weinberg equilibrium gives the expected genotype frequencies in a sexual population
Twee stappen
- From genotype frequencies allele frequencies can be deduced
- Allele frequencies predict genotype frequencies in next
generation
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper Jessica1995. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €3,19. Je zit daarna nergens aan vast.