Conservation Flashcards
what is inbreeding depression?
the reduction in fitness a result of increased inbreeding. This is caused by increased homozygosity and the presence of recessive deleterious mutations being expressed in a population. this results in a decrease in Ne which decreases the population size further.
where can inbreeding depression be observed?
in zoos
how can you measure inbreeding?
inbreeding coefficient. F = the probability of picking the same allele in two individuals
what are the 3 examples of inbreeding depression in the wild?
- mandate song sparrows live on an isolated island. the population is cyclic and population crashes due to stormy weather etc. The scientists new all of the pedigrees of each so could calculate the inbreeding coefficient. they found that those who were more inbred, died more than those who weren’t
- scandinavian wolf population- russian wolf increased population
florida panther - swedish adders.
explain how Scandinavian wolf population demonstrates the effect of inbreeding
- a population of wolves was hunted to extinction. there was one female remaining. she increased the population slightly. the offspring were all interbred and for a long time the population remained low and constant. then suddenly the population increased. this was because a male russian wolf and been introduced to the population and had|||| added to the gene flow- decreasing homozygosity and increased viability
explain how the florida cougar showed the effects of inbreeding depression
the number were initially very high but the population was reduced to around 30 in 1991. the individuals are very inbred and show this through cardiac defects, a crooked tail trait and a cowlick. they have a low fitness and a low fecundity. due to the fact they were prone to genetic drift. then 8 pumas were added to the population and the species increased due to genetic restoration- the hybrid kittens had a greater fitness
how can inbreeding be calculated without knowing the pedigrees of a population?
you can use genetic markers such as micro satellites which measure the level of heterozygosity of these markers within individuals within a population
how can the used of genetic markers on loci not always be reliable- give an example of this in nature
- in cheetahs there was found to be low heterozygosity at allozyme loci. there was also a juvenile mortality rate. it was suspected that inbreeding was to blame. however they later found that heterozygosity at other loci was fine and that the high mortality rate was to do with predation
what was an example of the problems that arise when using morphology as a species guide during conservation
Tuataras are a lizard species. it was originally believed that across new zealand there was one species disperesed acorss the entire island and therefore it wasnt at risk. but in fact they are fractured into 3 subspecies which were unevenly spread- there was infact 1 subspecies which was found on found species and only this one was at risk- local differentiation.
what is studied in DNA barcoding?
a particular portion of the genome is studied: the cytochrome oxidase I enzyme found in mitochondria. this sequence is thought to be the same within species and different between species
how can DNA barcoding be measured and what is needed to determine different species?
relies on bar coding gap- requires that variation within a species relative with the amount of variation between species- must be a barcoding gap between intra specific varaition and interspecific variation.
when was DNA barcoding successful and unsuccessful?
in north american birds because no two species ahred the same COI sequence. there was a gap between the genetic distance between the variation seen within species and the variation seen in different species
but divergent COI clusters dont necessarily correspond to speicies- in peru butterflies: COI sequences were the same in different species- maybe tracking mitochondrial lineages isnt good when there are many speciation events that are ongoing
how can DNA sequencing be sued in forensics?
examining whale meat- sequence of DNA from whale meat and detecting illegal killing of whales who shouldn’t be hunted
