19 Flashcards
Formal definition of adaption?
A heritable change in allele frequency that changes a genotype which result in a change in phenotype that increase fitness.
Thermal performance curve (TPC)?
Species differ in the breadth and location of their TPC, and is adjusted by the phenotypic plasticity.
X axis: body temperature
Y axis: performance.
phenotypic plasticity?
A change in phenotype without a change in genotype.
Nurture?
How the environment shapes
Reaction norm diagram?
X axis: environment
Y axis: trait
It is a linear interpretation, and each line is a genotype.
Genotype-by-environment interaction?
When genotypes change differently in the environment.
!!!!!!!Plasticity vs adaptation?
Acclimation/Acclimatization?
A temporary change in phenotype in response to a change in environment (e.g., seasons).
Developmental plasticity?
A longer lasting change in phenotype in response to a change in environment experienced during early development.
Transgenerational plasticity?
When environmental conditions experienced by parents impact the phenotype of their offspring. A form of non-genetic inheritance.
Epigenetics?
Heritable phenotype changes that do not involve alterations in the DNA sequence (e.g., heritability of phenotypic plasticity).
Inbred?
Almost Genetically identical.
Agouti gene?
Induces fur pigmentation. mRNA is silenced if adding methyl groups, but is continually active without methyl.
Epigenetic mechanisms/changes?
•Methylation: sticking a CH group to DNA.
•Histone modification: change
•Micro-RNAs (non-coding RNAs): interact with DNA and alter transcription.
When a DNA is super coiled, it is difficult to?
Transcribe.
DNA methylation and histones change?
The packing of DNA which change transcription.
Can epigenetic modification alter which genes are turned on or off?
Yes since they affect DNA packing.
Polar bear life cycle?
•Spring: polar bears mate on sea ice
•Throughout spring and summe,r they forage
•Implantation of fertilized eggs is delayed until fall.
•Only occurs if the female is in goo health
•Fall - females den on land
•offspring is born in the winter where there is no food. The mother does not eat during this period (4-8 months). That is where the pups feed on the mother’s milk.
Polar bears eat during?
The spring and summer. They eat ringed seals, but also walrus, bowhead whales, narwhal, and some terrestrial foods.
Polar bears have higher/equal/lower metabolic rate compared to other bears?
Higher
Adaptation of polar bears that have high energy requirement?
long digestive tract to extract as much food as possible
Carnivores have complex/simple digestive tracts?
Simple, but a long one can extract more nutrients.
