Experimental Design and Natural Selection Flashcards
What is biological fitness
The ability to survive to reproductive age, find a mate, and produce offspring
What is directional selection
a mode of natural selection where a single phenotype is favoured, causing allele frequency to continuously shift in one direction
What is a gene pool
The combination of all the genes (including alleles) present in a reproducing population or species
What is heritable variation
The variance of the breeding values among individuals
What is a null hypothesis
proposes that no statistical significance exists in a set of given observations
What is an alternate hypothesis
Proposed statement in hypothesis test. Indicates existence of statistical relationship between variables and usually aligns with research hypothesis
What is natural selection
process where populations of living organisms adapt and change to their environment
- organisms better adapted to their environment tend to survive and produce more offspring
What is replication
process which the genome’s DNA is copied in cells
What is sexual dimorphism
The systematic differences in form between individuals of different sex in the same species
What is sexual selection
Natural selection arising through preferences by one sex for certain characteristics in individuals of the other sex
What are tradeoffs
A condition which an increase in performance of one trait causes a decrease in the performance of another, given limited amount of available resources
What is statistically significant difference
Indicates the difference is unlikely to have occurred by chance
What are dependent variables
what is measured in experiment, what is affected
What are independent variables
variable changed or controlled in experiment to test the effects of the dependent variable
What are standardized variables
variables that stay the same throughout the experiment to see how independent and dependent variables interact with each other
What does homosporous mean
produces only one kind of spore
What are two conditions needed and sufficient for natural selection
- heritable phenotypic variation in the population
- the heritable variation must lead to differential reproductive success
what do variegated plants mean
reduced chlorophyll…
- in brassica rapa, trait heritable in chloroplast DNA= maternal inheritance
What does a 95% confidence interval mean?
if we repeated this study 100 times we would expect the mean value to fall with these bars 95/100 times
What does it mean if confidence intervals overlap
difference between the mean values are not statistically significant
What does it mean if confidence intervals don’t overlap?
it is statistically significant
What is the tradeoff with energy investments in reproductive structures
- energy used - less energy to invest in growth and accumulation of stored reserves
- reproduce early and a lot
