Introduction Flashcards
Long term response of animals to their environment. (2 types)
- Biotic (relating to other organisms)
- Abiotic (Physical)
Abiotic factors (2)
- climate change
- Whip tail lizard warming itself in the sun
Dispersal
the permanent movement of an animal away from it’s home range
Biotic factors (3)
- Lion chasing gazelle - Rhinocerus beetles fighting - presence of humans
Army ants have strict social hierarchies.
- queen - soldiers - workers - winged males(don’t work for the colony just fertilise females)
sequential hermaphrodites
one individual can change from producing female to male gametes, or vice versa (in other species)
What determines the change in sex? (4)
- sex determination depends on social circumstances - Bluehead wrasse - reared alone - all become female - Live in a group -one becomes male - Protogyny
Clownfish are ….. ?
protandrous
protandrous
Start as male -> can change later to a female if there is no breeding female in a group
Trait / Phenotypic trait
an observable characteristic of an organism
Traits (4)
- Behavioural Traits (clearner / non-cleaner/ dominant / subordinate) - Morphological traits (blue headed/ yellow headed / large / small) - Physiological traits (gene expression) - life history traits (timing of breeding)
How do traits evolve? Natural selection happens when: (4)
- there is variation among individuals in a trait - when differences in the trait are related to differences in fitness - Fitness is a measure of how successful an individual is at transmitting its genes to the next genereation - Evolution results from natural selection when the trait is genetically transmissable (has heritability)
What does it mean if an animal has fitness 0?
The animal doesn’t reproduce
The plot of phenotypes in parents and offspring is used to measure heritability h^2. What are the limitations?
Similarity can also be caused by: - growing up in the same place - parental care - learning
What does h^2 = 0 mean?
can’t measure heritability
Selection usually varies how? (2)
- Spatially - Temporally
Frequency dependent selection
A & B are two color types in a population Many A’s profit B Many B’s profit A
What leads to faster evolution?
Stronger selection. s = 0.05 (fast) s = 0.01 (slow)
Evolution results when there is a correlation between what: (2)
- a correlation between phenotypes of parents and offspring - a correlation between the phenotypes of parents and their fitness
Modes of natural selection and explain them: (3)
- Directional selection
- Diversifying selection
- Stabilizing selection
Genotype by environment (G X E) interactions
