Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
Positive Frequency Dependence? |
When a phenotypes fitness increases as it becomes more common, very unstable for mixed populations, one to extinction the other to fixation |
|
|
Positive Frequency Dependence example? |
Heliconius butterflies exhibit mullerian mimicry, 2 or more unpalatable species share colouring. |
|
|
Negative frequency dependence? |
a phenotypes fitness increases as it becomes rarer, v stable for mixed populations as pushed back to equilibrium |
|
|
Neg. freq. dep. example? |
Papilio dardinus, batesian mimicry, palatable mimics unpalatable |
|
|
Explain the wasp fig relationship? |
Female lays eggs in fig, damaging herself in the process but pollinating the fig. Eggs hatch, males mate and make a tunnel out of the fig which the females leave through to pollinate more, males die shortly after. Co-evolution |
|
|
Evolutionary Stable Strategy |
One, which if adopted by every member of the population, cannot be invaded by another strategy. |
|
|
How does ESS differ from optimal strategy? |
ESS depends on every member of the population, while optimal trait is specific to individuals. |
|
|
An example of an ESS? |
Red deer not killing each other in a rut, much higher risk for the deer. |
|
|
Quantitative Characters? |
A measurable phenotype that depends on cumulative actions of many genes and their environments. |
|
|
Example of quantitative character? |
Tobacco carolla length, two homozygous extremes and cross, gives intermediates with environmenatl variation (F1). Cross members of F1. would expect 1:2:1 ratio if one locus, but no, so many loci are involved. |
|
|
Polygenic inheritance? |
Variation caused by many separate genes that work together with cumulative affect, giving undistinguishable phenotype classes |
|
|
Testing for inheritance? |
Offspring phenotype similar to parent. Draw line graph. |
|
|
Heritability? |
Extent to which a character is controlled by additive genetic variation, the proportion of phenotypic variance in a character that is due to its genetic variance. |
|
|
Heritability example? |
Ground finch bill depth, over two years the bill depth changed but heritability did not. Test not due to environment/ parents by "foster parents", still the same outcome therefore genetic. |
|
|
Meristic characters, and example? |
Mulitple loci control phenotype, but it only expressed in whole numbers. Fruit fly bristles Litter number in mice. |
|
|
Threshold characters and example? |
Character is only expressed if sufficient genetic or environmental factors beyond the threshold point. Guinea pigs get 4 toes (not three) if threshold exceeded. |
|
|
Directional selection and example? |
one extreme phenotype has greater selection than the other. E.g. ground finch bill in Daphne Major, drought led to new seed type, which selected strongly for a particular bill type |
|
|
Stabilising selection and example? |
The mean phenotype experiences the greatest selection, while extremes experience the least. Stabilises the phenotype E.g. Clutch size in collared flycatchers |
|
|
Disruptive selection and example? |
The extremes experience the most selection, while the mean experiences the least. E.g. black bellied seed crackers, small beaks good for soft seeds, big for hard seeds, intermediate not good at either. |
|
|
Breeders equation? |
R=h(^2) S R= response to selection S= selection differential |
|
|
Hamiltons Social interactions? |
Mutual benefit- e.g. monkeys grooming Selfishness- e.g. fighting over food Altruism- e.g meerkat family has only one mating pair Spite- not really seen |
|
|
Group selection? |
Natural selection acts on group level not individual. |
|
|
Wrights co-efficient of relatedness? |
Probability that an allele present in an individual is also present in relatives (r) Full sib- 0.5 Parent/ offspring- 0.5 1/2 sib- 0.25 Aunt/ nephew etc.- 0.25 G'parent/ child- 0.25 |
|
|
Hamilton rule? |
Altruism will evolve if: r x benefit to donor> the cost to the donor |
|
|
Inclusive fitness? |
Fitness via indirect reproduction |
|
|
Kin selection and conditions? |
inclusive fitness, altruism to care for kin. Kin recognition or low dispersal needed. |
|
|
Kin Selection examples? |
1.) Long tailed tit, failed breeder return to old nest to help rear siblings.
2.) Pied Kingfisher, many more males than females (females die making nest), so many un mated males become helpers. Primary helpers= previous offspring, secondary helpers= unrelated. Primary gain indirect fitness, secondary direct through sneak mating
|
|
|
3 types of altruism? |
Self interest- e.g. secondary helpers Mutual benefit- repaid later Kin selection- inclusive fitness |
|
|
Eusocial characteristics? |
live in groups cooperative care of young reproductive division of labour overlapping generations |
|
|
How are ants eusocial? |
Haplodiploid, male develop from unfertilised egg, female are very related to each other (0.75), not to brothers (0.25). More related to each other then they would be their own offspring, so delicate one queen to mate, and they help her. |
|
|
How are naked mole rates eusocial? |
1 reproductive male, with 1-3 reproductive males. Environment is extremely harsh, so it is more beneficial for the individuals to stay and act as a group, than leave and probably die |
