The gene pool
is the total of all alleles in a population. Evolution
is a change in the gene pool.
Kingdom, Phylum, Class, Order, Family, Group, Species.
Since organisms in the same group have similar genetic structures, they share similar phylogenies (evolutionary history). For isntance all mammals belong to the class Mammalia
and the phylum Chrodata
There are new superkingdoms calld domains
. The three domains are Bacteria, Archaea, and Eukarya. The kingdoms of protista, fungi, plantae, and animalia into eukarya.
- Species is loosely limited to, but not inclusive of, all organisms that can reproduce fertile offspring with each other. Organisms which normally reproduce selectively fit offspring in the wild.
- -The way in which a species exploits its environment is called its niche. Survival of the fittest predicts that one species will exploit the environment more efficiently then another, leading to the extinction of the other with the same niche. The definition of the fittest organism in this theory is the organism which can best survive to reproduce offspring which will, in turn reproduce.
There are two opposing reproductive strategies, r-selection and k-selection. R-selection
involves producing large numbers of offspring that mature rapidly with little or no parental care. R-strategists generally have a high brood mortality rate.
involves small brood size with slow maturing offspring and strong parental care. K-strategists tend to have a sigmoidal growth curve
which levels off at carrying capacity
. The carrying capacity is the maximum number of organisms that an environment can maintain.
is the process by which new species are formed. When gene flow ceases between two sections of a population, speciation begins. Factors which cause this include geographical, seasonal, and behavioral isolation. Adaptive radiation
occurs when several separate species arise from a single ancestral species.
A species may face a crisis so severe as to cause a shift in the allelic frequencies of the survivors of the crisis. This is called an evolutionary bottleneck.
exists when two or more species evolving from the same group maintain a similar structure from the common ancestor. However, two species may independently evolve similar structure in convergent evolution
is a relationship between two species. The relationship can be beneficial to both (mutualism)
, beneficial to one and neutral to the other (commensalism)
, or beneficial for one and detrimental to the other (parasitism)