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
Thynnid wasp Nuptial Gift
The flightless female is carried around by the male to feed and judges his performance to see if she will mate with him
Damselfly/Dragonfly
Males engage in aerial combats to see who gets to mate with the females
Determined by the amount of fat reserves, generally less fat males can outcompete the others
Widowbird handicap
Males have long and elaborate tails that handicap their survival ability
Females prefer these individuals as it is an honest signal of fitness if they can survive with it
Anolis lizard extravagant males
These lizards in the Caribean islands were tested to see if there was a connection between male extravagance and parasite load to test the Hamilton-Zuk hypothesis
They found no support for the parasite hypothesis in this study
Sailfin mollies symmetry
During mating events, males will show both sides of their body to the females to show their symmetry and females will evaluate this
Females have a preference for symmetrical males as it shows the better genotype
Barn Swallow symmetry
When tested it was seen that females prefer the males with the most symmetrical tails
They had no preference for tail length
Facial symmetry in humans
A North American study showed a correlation between facial symmetry and attractiveness
However, a similar study done in Mexico showed no correlation between facial symmetry and attractiveness
A human study of attraction to relatedness
In a human study, it was found that females preferred the smell of males that were least similar in genotype
With the exception that females on hormonal birth control preferred the smell of males most similar in genotype
Humpback whale Migration
Whales feed in cold northern waters but move south to give birth in warmer waters
Connecticut Warbler
Breeds up north in summer due to higher productivity of plants
Flys down south in winter to feed during their productive months
Pacific Salmon migratory route
Travel out into the open ocean with the young as there are fewer predators so it is safer for juvenile fish to feed
Monarch Butterfly Migration
Gen #1 Overwinter in Mexico: adults leave mountains in Mexico (Feb-Mar) feed on nectar and lay eggs in milkweed en route to Florida
Gen #2 eggs hatch 4 days: caterpillar feeds then into an adult that migrates north, eat nectar lay eggs in milkweed en route to Canada
Gen #3 is the same as #2 but they head west
Gen #4: southern migration to Oyamel fir forest Mexico
Penguin Tag
Found that tagged penguins had a higher mortality rate and had fewer chicks
Dall Mountain sheep
Collection of sheep skulls to age them based on growth rings
Used to construct the first-ever life table
