Midterm #1 Case Studies Flashcards
Drosophila Genetic Variation related to Population Size
A study done showing amount of heterozygosity after so many generations with a manipulated initial population size
Showed that smaller samples died out due to homozygosity quicker
Survivorship of Newborn zoo animals
All examples of zoo animals showed higher juvenile mortality rate in the inbred animals compared to the outbred animals
Disease susceptibility in California sea lions
When testing the dead sea lions that had washed up on shore the individuals that had died of pathogens and diseases had a high level of relatedness
Compared to the individuals who died of trauma were not closely related
Showed inbreeding (homozygosity) increased mortality via pathogens
Population persistence of Rocky Mountain Sheep
At a large population size, most of the population persists for many years
Smaller populations die out faster with very small populations reaching extinction
Large Carnivores of Vancouver Island
Based on mathematics we understand that Vancouver Island is not large enough to support the MVA for large carnivores
They survive due to heavy immigration
Drosophila Immigration
Studies showing that even a small amount of immigration allows for the persistence of a population that would otherwise die out
His snail species in the ocean
Saw that there was a light form and a dark form.
One form had better camouflage on the exposed kelp
But the other form had better camouflage on the submerged kelp from the fishes point of view
Pied-wagtail
Their preys (beetle) caloric value increases exponentially with size, but so does handling time
So they eat the beetles that maximize net calorie gain
Preferentially feed on 7mm beetles
Bison salt licks
We find that bison will trail off good feeding areas simply to gain access to salt
Moose terrestrial vs aquatic plant diet
Aquatic plants are high in sodium, but calorically poor
Terrestrial plants are low in sodium, but calorically dense
Needs to balance both salt and calories with a limited stomach volume
This means there is a very narrow range of optimal diet
Caribou Migration Mineral Content
Arctic caribou and reindeer will travel far distances to the coast before they give birth
This is because they require higher salt ingestion for better breast milk for young
The tradeoff of less calorie dense foods for more salt in the diet
Black-capped chickadee territory
These birds show intraspecific territoriality but no interspecific territoriality
Great Tit territory size
When birds were removed from habitat to reduce density there was the expansion of some birds territories as well as new arrivals
Showed that when density is high territories are smaller
Wrasse Hermaphrodism
These fish are sequential hermaphrodites
Dominant male (alpha) is the only breeding male and dominant female (beta) is the only breeding female
The sub-adult juveniles are genderless
Competition for alpha position
Hanging Fly Nuptial Gift
Males bring insect prey to females to solicit mating
Larger gift solicited longer copulation and therefore more sperm transfer
