Flashcards in 8. Evolution and Psychopathologies reading Deck (68)
what is the standard model of a fitness landscape
For fitness landscapes can have a standard model i.e. bell curve shape For example rabbits with medium levels of cautiousness of the highest fitness so selection shapes the population mean to the peak, where fitness for genes and individuals coincides with maximum health.
describe the cliff edged model of a fitness landscape
However, fitness landscape can be a symmetrical. Sometimes fitness increases as a trait is pushed in One Direction, but going one step too far results in going off the cliff just like the bird nest that had one egg to many.
what is an e.g. of cliff edged fitness that humans have induced?
breeding fast horses and leg breaking
how does cliff edged fitness model fit in well with schizophrenia
This model fits well with the idea that schizophrenia is intimately related to language and cognitive ability. It also fits well with the observation that schizophrenia may be intimately related to human capacity for theory of mind, or ability to intuit other peoples motives and cognitive abilities in general.
what would we predict diseases resulting from cliff edged fitness to look like?
Diseases resulting from cliff edge fitness should be highly heritable, Observed a few percent of the population, and the rest will be influenced by the complex interactions of many normal alleles that have about the same small influence on disease risk. This matches the data for many diseases.
in cliff edged models what do problems result from?
In cliff-edged models, the problem Results not From defective genes but from steep slopes on fitness landscapes that result from intrinsic trade-offs.
what does considering cliff-edged fitness landscapes encourage
Considering cliff-edged fitness landscapes encourages looking for traits and trade offs that may be crucial for explaining dire disease.