Search results
Results From The WOW.Com Content Network
r-selected species are those that emphasize high growth rates, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood (i.e., high r, low K). [10]
A Type I survivorship curve is characterized by the fact that death occurs in the later years of an organism's life (mostly mammals). In other words, most organisms reach the maximum expected lifespan and the life expectancy and the age of death go hand-in-hand (Demetrius 1978). Typically, Type I survivorship curves characterize K-selected species.
Every irreducible complex algebraic curve is birational to a unique smooth projective curve, so the theory for curves is trivial. The case of surfaces was first investigated by the geometers of the Italian school around 1900; the contraction theorem of Guido Castelnuovo essentially describes the process of constructing a minimal model of any smooth projective surface.
Survival analysis is a branch of statistics for analyzing the expected duration of time until one event occurs, such as death in biological organisms and failure in mechanical systems. This topic is called reliability theory , reliability analysis or reliability engineering in engineering , duration analysis or duration modelling in economics ...
A survivorship curve is a graph showing the number or proportion of individuals surviving to each age for a given species or group (e.g. males or females). Survivorship curves can be constructed for a given cohort (a group of individuals of roughly the same age) based on a life table. There are three generalized types of survivorship curves: [1]
One equation used to analyze biological exponential growth uses the birth and death rates in a population. If, in a hypothetical population of size N, the birth rates (per capita) are represented as b and death rates (per capita) as d, then the increase or decrease in N during a time period t will be = ()
This genetic selection causes the allele frequency to shift toward the chosen extreme over time as allele ratios change from generation to generation. The advantageous extreme allele will increase in frequency among the population as a consequence of survival and reproduction differences among the different present phenotypes in the population.
These charts depict the different types of genetic selection. On each graph, the x-axis variable is the type of phenotypic trait and the y-axis variable is the amount of organisms. Group A is the original population and Group B is the population after selection. Graph 1 shows directional selection, in which a single extreme phenotype is favored.