Bio Midterm

Similar traits that arose independently because of evolution.

The concept that the organisms living on earth today are modified descendents of common ancestors.

1. The modern species came from a succession of ancestors who were different.

2. Natural selection is a primary cause of descent with Modification.

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates because of those traits.

New layers of sediment cover older ones and compress them into superimposed layers of rock called strata.

Viewed species as fixes and unchanging.

Concluded that life forms could be arranged on a ladder of increasing complexity.

1. Developed 2 part way for naming species.

2. Developed a nested classification system, grouping similar species into increasingly general categories.

1. The older the strata the more dissimilar fossils were to current life forms.

2. From layer to layer some species arose and some disappeared.

3. Opposed the idea of evolution.

4. Each boundary between strata represent a sudden catastrophic event.

Proposed earth geologic features could be explained by gradual mechanisms.

The same geological processes are operating as in the past, at the same rate.

Evolutionary change explains patterns in fossils and the match of organisms to their environments.

1. Use and disuse

Body parts being used are growing stronger while those not being used deteriorate.

2. Inheritance of acquired traits

An organism could pass these modifications to an offspring.

Humans have modified other species over many generations by selecting and breeding individuals that possesses desired traits, a process called artificial selection.

Shared traits because a common ancestor had it.

The idea that decorations and ornaments evolve because females in the species prefer to mate with the most beautiful males.

Variationin a heritable characteristic that affects survival or reproduction

Changeover time in the gene pool

Godcreated species and put them down wherever they are

1. The pattern of evolution- the observation that life has evolved over time.

2. The process of evolution- that natural selection is the primary cause of the observed pattern of evolutionary change.

1. Natural selection is a process of editing, not a creative mechanism.

2. In species that produce new generations in a short periods of time, evolution by natural selection can occur rapidly- in just a few years or decades.

3. Natural selection depends on time and place. It favors those characteristics in a genetically variable population that provide an advantage in the current, local environment. ˤ

Characteristicspresent in an ancestral organism are altered (by natural selection) in itsdescendants over time as they face different environmental conditions.

Similarityresulting from common ancestry

Variationson a structural theme that was present in a common ancestor.

Remnantsof features that served a function in the organism's ancestors.

Adiagram that reflects evolutionary relationships among groups of organisms.

Theindependent evolution of similar features in different lineages.

Analogousfeatures share similar function, but not common ancestry.

Thescientific study of the geographic distributions of species.

Variations in genes

A functionless or rudimentary structure in onespecies that has an important function in other, related species.

Inheritedsimilarities during development, despite differences in adults.

Similaritiesamong organisms at the molecular level

Innearly all organisms in the same codons (nucleotide triplets) specify the sameamino acid.

Stayedthe same over evolutionary time because of selection against change.

Focusingon evolutionary changes in populations, we can define evolution on its smallestscale, called microevolution, as a changein allele frequencies in a population over a generation.

Natural Selection, Genetic Drift (Change events that alter allele frequencies), Gene Flow (The transfer of alleles between populations)

Thecontribution an individual makes to the gene pool of the next generationrelative to the contributions of other individuals.

Occurswhen conditions favor individuals exhibiting one extreme of a phenotypic range,thereby shifting a population's frequency curve for the phenotypic character inone direction or the other.

Occurs when conditions favor individuals atboth extremes of a phenotypic range over individuals with intermediatephenotypes.

Actsagainst both extreme phenotypes and favors intermediate variants. This mode ofselection reduces variation and tends to maintain the status quo for aparticular phenotypic character.

Adifference in secondary sexual characteristics between mail and females of thesame species.

Meaning,selection within the same sex, individuals of one sex compete directly for mates of the opposite sex.

Also called mate choice, individuals of onesex (usually the females) are choosy in selection their mates from the othersex.

Includes frequency-dependent selection andheterozygote advantage.

Thefitness of a phenotype depends on how common it sin in the population.

Ifindividuals who are heterozygous at a particular locus have greater fitnessthan do both kinds of homozygotes, they exhibitheterozygous advantage.

Somethingthat arose via convergent evolution

Thecharacterizes of an organism as a result of genes and the environment.

Geneticcomposition of an organism

Consistsof all copies of every type of allele at every locus in all members of thepopulation.

In a population that is not evolving, allele and genotype frequencies will remainconstant from generation to generation, provided that only Mendeliansegregation and recombination of alleles at work. Such population is said to bein Hardy-Weinberg equilibrium.

1. Nomutations

2. RandomMating

3. Nonatural selection

4. Extremelarge population size

5. Nogene flow

Differencesamong individuals in the composition of their genes or other DNA sequence.

Differencein DNA sequence that do not confer a selective advantage or disadvantage.

Aprocess in which traits that enhance survival or reproduction then dot increasein frequency over time.

Chanceevents can also cause allele frequencies to fluctuate unpredictably from onegeneration to the next, especially in small populations.

Whena few individuals become isolated from a larger population, this smaller groupmay establish a new population whose gene pool differs from the sourcepopulation.

Thepopulation has passed through a "bottleneck" that reduces its size.

Is significant in small populations

Can cause allele frequencies to change at random

Can lead to a loss of genetic variation within populations

Can cause harmful alleles to become fixed

Thetransfer of alleles into or out of a population due to the movement of fertileindividuals or their gametes.

Having2 copies of each gene

Thealleles of an individual has for a gene

Thefunctional unit of heredity

Location of a gene on a chromosome

Proportionof all the copies of a given gene that are in a particular allele

1.Calculate the observed genotype frequencies

2. Calculate the allele frequencies

3. Predict the expected genotype frequencies

4. Compare observed to expected genotype frequencies

5. Do statistical test to decide if observed/expected are sig. different

If observed is closeto expected: the population is said to be in "equilibrium"

Frequency of TT= # TT/Total individuals

Frequency of Tt= #Tt/ Total Individuals

Frequency of tt= #tt/Total individuals

Frequency of T= 2(TT) + Tt/2 (total)

Frequency of t= 2(tt) + Tt/2 (total)

T^2 (allele frequency^2)

(expected genotype)(Total # of Individuals)

2(allele frequency of T)(allele frequency of t)

1. It doesn't affect the phenotype

2. It affects genotype, but not fitness

Harmfulrecessive alleles "hide out" in heterozygotes, shielded fromselection.

Positive selection for allele inheterozygotes/Negative selection against the allele in homozygotes

Theevolutionary history of a species or group of species.

Adiscipline focused on classifying organisms and determining their evolutionaryrelationships.

How organisms are named and classified.

Thetwo part format of the scientific name.

Thefirst part of a binomial is the name of the genus

Thenamed taxonomy unit at any level of the hierarchy.

Groupsof organisms that share an immediate common ancestor that is not shared byany other group.

A branch point within the tree (often drawnfarthest to the left) represents the most recent common ancestor of all taxa inthe tree.

Alineage that diverges from all other members of its group early in the historyof the group.

Apicture of how we think the things at the end evolved in respect to the otherthings.

Phenotypicand genetic similarities due to shared ancestry.

Similaritiesbetween organisms that's due to convergent evolution rather than share ancestry(homology).

Commonancestry is the prime criterion used to classify organisms.

Consistsof an ancestral species and all of its descendants.

Consistsof an ancestral species and some, but not all, of its descendants.

Includesdistantly related species but does not include their most recent commonancestor.

A character that originated in an ancestor ofthe taxon.

A species or group of species from anevolutionary lineage that is closely related to, but not part of the group ofspecies that we are studying (the ingroup).

Weshould first investigate the simplest explanation that is consistent with thefacts.

Identifies the tree most likely to haveproduced a given set of DNA data, based on certain probability rules about howDNA sequences change over time.

1. Bacteria

2. Archaea

3. Eukarya

Mostof the currently known prokaryotes

A diverse group of prokaryotic organisms that inhabit a wide variety of environments.

All the organisms that have cells containing true nuclei. Also includes many groups of single-celled organisms as well as multicellular plants, fungi, and animals.

1. Plantae

2. Fungi

3. Animalia

Aprocess in which genes are transferred from one genome to another throughmechanisms such as exchange of transposable elements and plasmids, viralinfections, and perhaps fusions of organisms (as when a host and itsendosymbiont become a single organism).}

Thefirst part is the name of the genus to which the species belongs and the secondis unique to the species within the genus.

Characteristicspresent in an ancestral organism are altered (by natural selection) in itsdescendants over time as they face different environmental conditions.

Related species can have characteristics that have an underlying similarity yet function differently.

False; It is common for organisms to have genes that have lost their function, even though the homologous genes in related species may be fully functional.

False; they are just hypothesis.

True

False; Descent with modification was, but natural selection was not for a long time.

1. Structural

2. Developments

3. Molecular

Olderfossils on bottom, younger fossils on top

False; A shared (homologous) structure can be modified into many forms by natural selection.

False; it affects it as a group

False; The outcome of natural selection is notrandom. Instead, natural selection consistently increases the frequencies ofalleles that provide reproductive advantage, thus leading to adaptiveevolution.

Selection acts more directly on the phenotype than on the genotype; it acts on the genotype indirectly, via how the genotype affects the phenotype.

Yes as natural selection increases the frequencies of alleles that enhance survival or reproduction.

False; it introduces both advantageous and disadvantageous.

Because they are hidden from selection when in heterozygous individuals.

Selection can act only on existing variations Evolution is limited by historical constraints Adaptions are often compromises

Chance, natural selection, and the environment interact

Homology

Genes or

The environment or

Both

True

Selection favors individuals whose heritable phenotypic traits provide higher reproductive success than do the traits of other individuals.

False; it arises gradually

No; Forthat to happen, one or more of the factors that cause evolution must be atwork.

That allele is said to be fixed in the gene pool, and all individuals are homozygous for that allele.

Individuals may be either heterozygous or homozygous.

Determine what genetic makeup of a population would be if it were not evolving at that locus. We can then compare that scenario with the data we actually observed for the population.

We can conclude that the population is not evolving.

This suggests that the population may be evolving- and then we can try to figure out why.

When the observed genotypic and phenotypic frequency matches the expected.

No matter how many times the deck is reshuffled the deck itself remains the same. And the repeated shuffling over the generations cannot, in itself, change the frequency of one allele relative to another.

single gene locus, with different alleles producing distinct phenotypes.

the influence of two or more genes on a single phenotypic character.

True

introns, the region retained in mRNA after RNA processing.

non-coding segments of DNA lying between exons

No

No

True

No

mutation, gene duplication, or other processes produce new alleles and new genes.

Yes

Mutation

No.

cell lines that produce gamete

Theunique combinations of alleles that each individal recesives from its parents.

Crossing over

Independent assortment of chromosomes fertilization

alleles being passed to the next generation in proportions that differ from those in the present generation.

Byconsistently favoring some alleles over others

True

The bottleneck effect

If it is extensive enough

True

Neutral

True

True

False

Genus

Family

Orders

Classes

Phyla

Kingdoms

Domains

Family

Order

Class

Phyla

Order

Domain

No

the common ancestor of the two evolutionary lineages diverging from it.

Does not

True

No

Descent

when particular species evolved or how much change has occurred in each lineage.

False; we should not

True

True

they are descended from sequences carried by a common ancestor.

True; kinda.In some cases, however, the morphological divergence between related species can be great and their genetic differences small (or vice versa).

similar environmental pressures and naturalselection produce similar adaptations in organisms from different evolutionarylineages.

the complexity of the characters that are being compared.Themore elements that are similar in two complex structures, the more likely it isthat the structures evolved from a common ancestor.

clades, each of which includes an ancestral species and all of its descendants.

the most recent common ancestor of all members of the groups is part of the group,

the most recent common ancestor is not.

morphology, paleontology, embryonic development, and gene sequences.

which characters were derived at the various branch points of vertebrate evolution.

False; it does not

the fewest evolutionary events, as measured by the origin of the shared derived morphological characters.

the most parsimonious tree requires the fewest base changes.

True

bacteria diverged from other organisms.

True

False; it can