Terms in this set (27)
Theory of biological evolution
A population changes in the proportion of a particular inherited trait through successive generations. VISTA
Changes in DNA, evolutionary change is based on the accumulation of several mutations
With the idea that some traits are passed from parent to offspring, Darwin believed that variation in traits occurred in individual species. These traits were then passed down from parent to offspring.
Individuals with heritable traits that make them better suited to their native environment are the ones that flourish and reproduce. As a result, the traits that favor reproductive success become more prevalent in a population over time. May result in a new species with a combination of multiple traits that are different from the original species.
a group of related organisms that share a distinctive set of attributes in nature
in the case of sexually reproducing species, members of one species cannot successfully interbreed with members of other species
the size of a population is reduced for one generation. Reduced genetic variation may lead the population to struggle with adapting to new selection pressures since the genetic variation that selection would act on may have already drifted out of the population
new colony is started by a few members of the original population, thus the colony may have reduced genetic variation from the original population, and left a non-random sample of genes in the original population.
brown eyes produce four offspring, some of the green eyes die, there is a possibility of there being more brown eyes in the population as a result. In other words, chance changes from generation to generation. Can cause big losses of genetic variation in small populations
anatomical structures that have no current function but resemble the structures of their presumes ancestors.
differential reproductive success
comparing successful reproduction rates between groups in a given generation of a species-Who makes more babies in a given generation; whoever makes more babies is successful
two species from different lineage have independently evolved similar characteristics because they occupy similar environments. example: giant anteater and enchidna
term used to describe two or more species reciprocally affect each other's evolution.
example: an evolutionary change in the morphology of a plant can affect the morphology of the herbivore that eats that plant. This then might change the evolution of that plant and so on.
the mechanisms that promote the formation of new species. Occurs by the accumulation of microevolutionary changes otherwise known as genetic changes. The new species turn out to be different from the species they were derived from.
single species evolves into a different species
the splitting or diverging of a population into two+ species
for sexually reproducing folk this process requires gene flow to become interrupted between two or more populations, hence limiting/eliminating reproduction between members of different pops
where a single ancestral species has evolved into a wide array of descendant species that differ in their habitat, form, or behavior.
when members of a species that are within the same range diverge into two or more different species, even though there aren't any physical barriers to interbreeding.
This is less common but occurs through polyploidy and adaptation to local environments
other homeland, occurs when a pop. becomes isolated from other populations and evolves into new species. Most common from of cladogenesis. Usually involves geographic barrier like land or water, these are usually slow(development of glacier/mountain range).
small populations may also move to a new location that's geographically isolated from the main pop.
shared derived character
a character of a group of organisms shared with ancestors of a group of organisms. Or a character that two lineages have in common
all alleles that could contribute from parent to offspring in a population
red queen hypothesis
Idea 1: Species have to "run" (evolve) in order to stay in the same place (extant).
Evolutionary change is required to stay in the same place
Formal: In tightly coevolved interactions, evolutionary change by one species (either prey or host) could lead to extinction of the other species(predator or parasite) and the probability of such changes might be reasonably independent of the species age.
idea 2: coevolution, specifically between hosts and parasites, could lead to sustained oscillations in genotype frequencies. This forms the core for one of the leading hypotheses for the persistence of sexual reproduction. Coevolutionary interactions with parasires may select for sexual reproduction in hosts as a way to reduce the risk of infection in offspring.
A human initiated process
set the identity of segments of insect bodies from head to tail. Are an example of "general purpose" control genes, they help lay out the basic body forms of animals, by setting up the head to tail organization.
occurs when an edible mimic resembles an unpalatable or poisonous model. Only the mimic benefits
when two or more distasteful or poisonous organisms resemble each other. Both species benefit because a predator who learns to avoid one species will most likely avoid the other, too.
how do new species form?
geographic isolation (allopatric and sympatric speciation) and reproductive isolation (pre and post zygotic barriers)