Bio Readings: Evolution, Population Genetics Flashcards
(Understanding Evolution) evolution by natural selection describes a mechanism for how species
change over time
(Understanding Evolution) ideas about the evolution of animals were reintroduced by naturalist buffon in the 18th century, who observed that various geographic regions have different … and …, even when the environments are similiar. It was also accepted that there were ..
plant; animal populations; extinct species
(Understanding Evolution) James Hutton, a Scottish naturalist, proposed that geological change occurred … by the accumulation of small changes from processes operating like they are today over long periods of time
gradually
(Understanding Evolution) Hutton’s theory contrasted with the predominant view that the geology of hte planet was a consequence of … occurring during a relatively brief past
catastrophic events
(Understanding Evolution) Geologist Charles Lyell, Darwin’s friend, presented the notion that the Earth was … than expected, which gave more time for … in species,
older; gradual change
(Understanding Evolution) Lamarck published his theory for the mechanism of evolutionary change known as …, by which modifications in an individual are caused by its …, or the … or … of a structure during its lifetime, could be inherited by its offspring and thus bring about change in a species
inheritance of acquired characteristics; environment; use; disuse
(Understanding Evolution) in the 19th century, the actual mechanism for evolution was independently conceived of and described by two naturalists: … and …
charles darwin; alfred russel wallace
(Understanding Evolution) both darwin and wallace had spent time exploring the natural world on expeditions to the
tropics
(Understanding Evolution) On the Galapagos Islands, Darwin observed species of organisms on different islands that were clearly similar, yet had …
distinct differences
(Understanding Evolution) one of the species Darwin observed were the ground finches. He imagined that the derivative species might be modified from one of the
original mainland species
(Understanding Evolution) Natural selection, also known as “…” is the more prolific reproduction of individuals with favorable traits that survive … because of those traits; this leads to …
survival of the fittest; environmental change; evolutionary change
(Understanding Evolution) according to Darwin, natural selection was an inevitable outcome of 3 natural principles:
- most characteristics of organisms are …
- more offspring are … than are able to …, so resources for survival and reproduction are … This leads to … for recourses in each generation (this came from reading an essay by Malthus about population limitation)
- offspring … among each other in regard to their characteristics and those variations are inherited
inherited; produced; survive; limited; competition; vary
(Understanding Evolution) Darwin and Wallace reasoned that offspring with inherited characteristics which allow them to best compete for limited resources will .. and have more … than those individuals with variations that are less able to compete. Because characteristics are inherited, these traits will be better … in the next generation. this will lead to change in populations over generations in a process called …
survive; offspring; represented; descent with modification
(Understanding Evolution) ultimately, natural selection leads to greater … of the population to its local environment; it is the only mechanism known for … evolution
adaptation; adaptive
(Understanding Evolution) The Grants performed an experiment on the Galapagos finches, showing … in the distribution of beak shapes over generations
natural selection
(Understanding Evolution) natural selection can only take place if there is … among individuals in a population. These differences must have some … basis, otherwise the selection will not lead to change in the next generation
variation; genetic
(Understanding Evolution) genetic diversity in a population comes from two main mechanism: … and …
mutation; sexual reproduction
(Understanding Evolution) …, a change in DNA, is the ultimate source of …, or new genetic variation in any population
mutation; new alleles
(Understanding Evolution) the genetic changes causes by mutation can have one of three outcomes on the phenotype:
a mutation affects the phenotype of the organism in a way that gives it …—lower likelihood of survival or fewer offspring
a mutation may produce a phenotype with a … effect on fitness
and many mutations will also have … effect on the fitness of the phenotype; these are called … mutations
reduced fitness; beneficial; no; neutral
(Understanding Evolution) sexual reproduction also leads to genetic diversity: twhen two parents reproduce, unique combinations of alleles assemble to produce the unique genotypes and thus … in each of the offspring
phenotypes
(Understanding Evolution) a heritable trait that helps the survival and reproduction of an organism in its present environment is called an
adaptation
(Understanding Evolution) scientists describe groups of organisms becoming adapted to their environment when a change in the range of genetic variation occurs over time that … or … the “fit” of the population to its environment
increases; maintains
(Understanding Evolution) whether or not a trait is favorable depends on the … at the time. The same traits are not always selected because environmental conditions can change
environmental conditions
(Understanding Evolution) when two species evolve in diverse directions from a common point, it is called
divergent evolution
(Understanding Evolution) similar phenotypes can evolve independently in distantly related species. thsi phenomenon is called …, where similar traits evolve independently in species that do not share a …
convergent evolution; common ancestry
(Understanding Evolution) natural selection acts on …, which in turn can shape an entire species
individual organisms
(Understanding Evolution) fossils provide solid evidence that organisms from the past are not the same as those found today, and they show a …
progression of evolution
(Understanding Evolution) scientists determine the age of fossils and categorize them from all over the world to determine when the organisms lived
relative to each other
(Understanding Evolution) another type of evidence for evolution is the presence of structures in organisms that share the same … Scientists call these synonymous parts …
basic form; homologous structures
(Understanding Evolution) some structures exist in organisms that have no apparent function at all, and appear to be residual parts from a past common ancestor.. These unused structures without function are called …
vestigial structures
(Understanding Evolution) another evidence of evolution is the … in organisms that share similar environments. These similarities occur not because of common ancestry, but because of similar …
convergence of form; selection pressures
(Understanding Evolution) embryology, the study of the development of the anatomy of an organism to its …, also provides evidence of relatedness between now widely divergent groups of organisms
adult form
(Understanding Evolution) structures that are absent in some groups often appear in their … and disappear by the time the adult or juvenile form is reached
embryonic forms
(Understanding Evolution) the geographic distribution of organisms on the planet follows patterns that are bet explained by evolution in conjunction with the movement of … over geological tie
tectonic plates
(Understanding Evolution) broad groups that evolved before the breakup of the supercontinent … are distributed worldwide. Groups that evolved since the breakup appear uniquely in regions of the planet
Pangaea
(Understanding Evolution) … has an abundance of endemic species: species found .. This is typical of islands whose isolation by expanses of water prevents species to … Over time, these species diverge evolutionarily into new species that look very different from their ancestors that may exist on the mainland
Australia; nowhere else; migrate
(Understanding Evolution) Like anatomical structures, the structures of the molecules of life reflect … Evidence of a common ancestor for all life is reflected int he … of DNA as the genetic material and in the near universality of the genetic code and the machinery of DNA … and …
descent with modification; universality; replication; expression
(Understanding Evolution) in general, the relatedness of groups of organisms is reflected in the similarity of their …–exactly the pattern that would be expected from descent and diversification from a common ancestor
DNA sequences
(Understanding Evolution) it is clear that the evolution of new functions for proteins commonly occurs after gene duplication events that allow the free modification of one copy by …,…, or … (changes in a population’s gene pool resulting from chance), while the second copy continues to produce a functional protein
mutation; selection; drift
(Understanding Evolution) evolution misconceptions:
misunderstanding of term … in science
belief that … evolve
belief that evolution includes an explanation of …
the belief that evolution is
theory; individuals; life’s origins; intentional
(Understanding Evolution) when thinking about the evolution of a characteristic, it is probably best to think about the change of the … of the characteristic in the … over time
average value; population
(Mechanisms) … and the … differences that are heritable and passed on to the next generation
descent; genetic
(Mechanisms) …, … (…), …, and … as mechanisms of change
mutation; migration; gene flow; genetic drift; natural selection
(Mechanisms) the importance of …
the random nature of … and the effects of a reduction in …
genetic variation; genetic drift; genetic variation
(Mechanisms) how .., …, and …. result in evolution by natural selection; and how different species can affect each other’s evolution through …
variation; differential reproduction; heredity; coevolution
(Mechanisms) evolution only occurs when there is a change in … within a population over time. These genetic differences are heritable and can be passed on to the next generation
gene frequency
(Mechanisms) genetic drift: … changes from generation to generation
chance
(Mechanisms) … and … cannot operate unless there is genetic variation
genetic drift; natural selection
(Mechanisms) besides mutations and sexual reproduction, … leads to genetic variation. It is any movement of genes from one population to another
gene flow
(Mechanisms) an important part of sex that contributes to genetic variation is
genetic shuffling
(Mechanisms) mutations are …, and not all of them matter for evolution
random
(Mechanisms) some mutations (those that don’t matter to evolution) are called …, which occur in … cells and won’t be passed onto offspring
somatic mutations; non-reproductive
(Mechanisms) the only mutations that matter to large-scale evolution are those that can be passed onto offspring. These occur in reproductive cells like eggs and sperm and are called
germ line mutations
(Mechanisms) a single germ line mutation can have a range of effects:
- … occurs in phenotypes (e.g. mutation in non-coding region of protein)
- … occurs in phenotype
- … occurs in phenotype
no change; small change; big change
(Mechanisms) Causes of mutations:
- DNA fails to … accurately. Most of the mutations that we think matter to evolution are ‘naturally-occurring.’
- … can create mutations, such as radiation exposure. These agents cause the DNA to …
copy; external influences; break down
(Mechanisms) gene flow is also called … and is any movement of … and/or the … they carry from one population to another. If gene versions are carried to a population where those gene versions previously …., gene flow can be a very important source of genetic variation
migration; individuals; genetic material; did not exist
(Mechanisms) Development is the process through which an embryo becomes an … and eventually dies. Through development, an organism’s genotype is expressed as a …, exposing genes to the action of natural selection
adult organism; phenotype
(Mechanisms) changes in the genes controlling development can have major effects on the … of the adult organism. Because these effects are so significant, scientists suspect that changes in developmental genes have helped bring about large-scale evolutionary transformations
morphology
(Mechanisms) developmental processes may … evolution
constrain
(Mechanisms) genetic drift–along with natural selection, mutation, and migration— is one of the … mechanisms of evolution
basic
(Mechanisms) Requirements for natural selection
1. there is … in traits
2. there is …
3. there is …
These three factors result in evolution by natural selection
variation; differential reproduction; heredity
(Mechanisms) … can also be shaped by natural selection.
behavior
(Mechanisms) in some cases, … has led to environmental changes that have caused populations to evolve through natural selection
human activity
(Mechanisms) biologists use the word fitness to describe how good a particular genotype is at … in the next generation relative to how good other genotypes are at it.
leaving offspring
(Mechanisms) a genotype’s fitness depends on the … in which the organism lives
environment
(Mechanisms) A genotype’s fitness includes its ability to …, find a …, produce …— and ultimately, leave its … in the next generation
survive; mate; offspring; genes
(Mechanisms) when natural selection acts on mate-finding and reproductive behavior, biologists call it
sexual selection
(Mechanisms) sexual selection acts on an organisms’ ability to obtain or successfully … with a …
copulate; mate
(Mechanisms) sexual selection usually works in 2 ways:
- …: males compete for access to females, the amount of … spent mating, and even whose … gets to fertilize her eggs
- …: females choose which males to mate with, how long to mate, and even whose sperm will fertilize her eggs
male competition; time; sperm; female choice;
(Mechanisms) artificial selection: people, instead of nature, select which organisms get to
reproduce
(Mechanisms) an adaptation is a feature that is common in a population because it provides some
improved function
(Mechanisms) adaptations can take many forms:
a behavior that allows better ….
a protein that functions better at …
or an anatomical feature that allows the organism to access a …
evasion of predators; body temperature; valuable new resource
(Mechanisms) … are not adaptations
vestigial structures
(Mechanisms) natural selection is … and …, having no goals
mindless; mechanistic
(Mechanisms) natural selection is NOT
random
(Mechanisms) coevolution describes cases where two or more species reciprocally affect each other’s
evolutoin
(Mechanisms) coevolution is likely to happen when different species have close ecological interactions with one another. These relationships include:
- …/… and …/…
- … species
- … species
predator;prey; parasite;host; competitive; mutualistic
(population genetics) different alleles of a particular gene:
polymorphisms
(population genetics) populations with two or more variations a particular characteristics are
polymorphic
(population genetics) population variation: the distribution of …. among individuals
phenotypes
(population genetics) understanding phenotypic variation sources in a population is important for determining how a population will … in response to different…
evolve; evolutionary pressures
(population genetics) natural selection and some of the other evolutionary forces can only act on …, namely an organism’s …
heritable traits; genetic code
(population genetics) because alleles are passed from parent to offspring, those that confer beneficial traits or behaviors may b e…, while deleterious alleles may not. Acquried traits, for the most part, are …
selected; not heritable
(population genetics) heritability is the fraction of phenotype variation that we can attribute to …, or …, among individuals in a population
genetic differences; genetic variance
(population genetics) the greater the heritability of a population’s phenotypic variaiton, the mroe susceptible it is to the … that act on heritable variation
evolutionary forces
(population genetics) we call the diversity of alleles and genotypes within a population …
genetic variance
(population genetics) inbreeding: the mating of …, which can have the undesirable effect of bringing together deleterious recessive mutations that can cause abnormalities and susceptibility to disease
closely related individuals
(population genetics) inbreeding depression: a family of … interbreed with each other, dramatically increasing the likelihood of two disease carriers …
carriers; mating
(population genetics) changes in allele frequencies that we identify in a population can shed light on how it is …
evolving
(population genetics) in addition to natural selection, there are other evolutionary forces that could be in play: …, …, …, …, and …
genetic drift; gene flow; mutation; nonrandom mating; environmental variances
(population genetics) selection pressure: driving …
selective force
(population genetics) genetic drift is the effect of …, by which some individuals will have more offspring than others
chance
(population genetics) … populations are more susceptible to the forces of genetic drift.
small
(population genetics) large populations are … against the effects of chance
buffered
(population genetics) natural events, such as an earthquake distater that kills–at random–a large portion of the population, can magnify genetic drift. this is known as …, and results in suddenly wiping out a large portion of the … At once, the survivors’ genetic structure becomes the entire population’s …
bottleneck effect; genome; genetic structure
(population genetics) another scenario in which populations might experience a strong influence of genetic drift is if some portion of the population … to start a new population in a … or if a … divides a population. In this situation, those individuals are an unlikely representation of the entire population, which results in the …
leaves; new location; physical barrier; founder effect
(population genetics) the founder effect occurs when the genetic structure changes to match that of the new population’s
founding fathers and mothers
(population genetics) gene flow: the flow of alleles in an out a population due to the … of … or …
migration; individuals; gametes
(population genetics) variable flow of individuals in and out of the group not only changes the population’s gene structure, but it can also introduce new genetic variation to populations in different … and …
geological locations; habitats
(population genetics) species evolve because of … accumulating over time
mutations
(population genetics) whether or not a mutation is beneficial or harmful is determined by whether it helps an organism survive to … and …
sexual maturity; reproduce
(population genetics) if individuals nonrandomly mate with their peers, the result can be a …
changing population
(population genetics) assortative mating: form of mate choice in which an individual’s preference is to mate with partners who are … to themselves
phenotypically similar
(population genetics) causes of nonrandom mating are … and …
mate choice; physical location
(population genetics) …: geographic separation between populations which can lead to difference sin the phenotypic variation between those populations
geographical variation
(population genetics) cline: a type of geographic variation; given species’ populations vary gradually across an
ecological gradient
