BIOL 1460 Ecology

What best represents the most likely evolution of RNA?

Its function changed over time

What should NOT be used as a measure of genetic diversity?

The number of methylated sequences

How do scientists define when a mass extinction has happened?

A large majority at least 75% of living species are wiped out of existence

How are mitochondira and bacteria similar

-Mitochondrial genes resemble proteobacterial genes -Their ribosomal structures and RNA are similar -They are similar in size -They both have DNA arranged in circular chromosomes NOT-They both produce all the proteins they need

What would be likely to have been a consequence if photosynthetic organisms had never evolved?

-Life would be much less diverse -Mitochondria-containing cells would not have evolved -There would be no oxygen on Earth -NOT-Most organisms would have gone extinct due to the increase in oxygen

Sitiuations stimulate adaptive radiation

-Mass extinctions -Adaptation of traits enabling the exploration of new resources -new food sources -major evolutionary innovations NOT- an increase in the rate of favorable genetic mutations

Factors directly involved in sympatric speciation

-Continuous habitat -Habitat differentiation -Phenotype -Sexual selection NOT- Artificial selection

Characteristics of an organisms likelyhood to be preserved in a fossil

-It became extinct because a volcanic explosion covered its territory in ash -It was abundant on the Eurasian continent at one time -It has a skeleton made of bones -It became extinct 5000 years ago Least- It lived in a tropical rain forest

What is an adaptive trait?

-It raises the average fitness of a population -It can reduce the chances of an individual's survival -It may occur at a biochemical level

True statement about fossil record

-Rate of speciation can be estimated by examining the fossil record -many missing transitional species in the fossil record, but more are discovered every year as scientist continue to investigate the fossil record -fossil record is made up of layers of sedimentary rock, called strata -many leaps or abrupt changes where new species appear suddenly and have unchanged morphology through several strata

What factor(s) constrain adaptation?

-genetic factors -trade-offs -historical factors

Why would a conservation biologist want to study sympatric speciation?

-understand the evolutionary relationships among the species in their study area -make recommendations regarding species diversity to agencies in charge of conserving biodiversity -understand the real amount of biodiversity in their study area -understand any hybridization that may be occurring between endagered and non-endangered organisms in their study area

Fossilized bones are discovered. Carbon dating indicates that they contain one-fourth the normal amount of carbon-14 found in the bones of a living specimen. The half-life of carbon-14 is 5,730 years. Approximately how old are the bones?

12000 years

How often does DNA polymerase attach the wrong nucleotide?

1:100,000

What variable in the Hardy-Weinberg equation expresses the heterozygous genotype?

2pq

When do the first cells appear in the fossil record?

3.5 billion years ago

A population survey shows that 160 out of 250 individuals express the recessive phenotype. What percentage of the population would you predict to be heterozygotes?

32% q^2= (160/250)=0.64; therefore sqrt(0.64)=0.8 p=1-0.8=0.2 2pq=2(0.2)(0.8)=0.32 or 32%

Approximately when do scientists believe life originated on Earth?

4.2 Billion years ago

Which of the following will most likely show the slowest evolutionary rate?

A bacteria population in a stable environment

what will most likely show the slowest evolutionary rate?

A bacteria population in a stable environment

Higher genetic variation is advantageous in what environment?

A changing environment

Genetic drift can lead to populations with reduced genetic variation. What is one evolutionary consequence of reduced genetic variation?

A decrease in the potential for adaptation to changing environments

Fitness

A description of an organism's ability to survive, reproduce and contribute to the gene pool of the next generation

Directional Selection

A type of natural selection favors a trend toward one extreme, shifting the population one direction or another

Disruptive Selection

A type of natural selection in which selection is against the common median trait, favoring the extreme variations.

Stabilizing Selection

A type of natural selection in which selection is against the extreme variations of a trait and favors the median

When the Murchison meteorite that landed in Australia was found to contain amino acids, how could scientists tell they had arrived with the meteorite rather than having contaminated it after it landed?

About half of the amino acids were D isomers and half were L isomers, whereas nearly all organic molecules on Earth are in the L configuration

A heritable trait that enhances individual fitness in a given environment is called a(n) ___.

Adaptation

How does gene flow influence sympatric speciation?

Adaptations that reduce gene flow cause sympatric speciation

Who independently formulated the hypothesis of natural selection before Darwin published his work?

Alfred Russel Wallace

What did the Urey-Miller experiment show that is still applicable today?

Amino acids and other complex organic molecules will spontaneously form in a reducing environment

An alternative form of a gene that occurs in the same place on a homologous chromosome (i.e., chromosome pairs of approximately the same length with the same characteristics but each is inherited from a different parent) is ___.

An allele

Modifications of a trait by the environment during an individual's lifetime ___________

Are not heritable

What type of adaptation is demonstrated by camouflage soiling in male rock ptarmigans?

Behavioral

What was Darwin's interest in joining the mission of the H.M.S. Beagle?

As a companion to the captain of the ship assisting in surveying the geology and biology of sites, primarily in South America

What is suggested by comparing the bones in a cat's front leg and a bat's wing?

Cats and bats share a common ancestor

Evolution

Change in allele frequencies in a population over time

Genetic Drift

Changes in the frequency of alleles in a population due to random chance. In small populations some alleles may be lost.

What is most likely a major factor causing mass extinction events over Earth's history?

Changes in the global climate, either cooling or warming

An endangered falcon population has been closely monitored and cared for in a protected area. Which data would be most appropriate to collect in order to best determine its recovery?

Comparison between the protected population and healthy populations of average heterozygous in a non-coding gene sequence

What unintentional feature of an organism's reproduction is essential for polyploidy to occur?

Errors in mitosis or meiosis

After Lynn Margulis's endosymbiont theory met opposition, what new evidence emerged in support of the theory?

DNA sequencing

How is fitness quantified?

Determine which genotype is most common in a population and compare its frequency to that of other genotypes

Natural selection _________

Did not play a role in the origins of life

The fossil record provides direct evidence for evolutionary relationships among living organisms and the history of life. So why is it controversial?

Fossil evidence suggests that the Earth is much older than what is written in religious texts

What is an example of reproductive isolation?

Gametes from two species of bear cannot fuse because of differences in the structure of their membrane proteins

What term is used to describe all the alleles at every locus for all individuals within a population?

Gene Pool

A forest fire kills 75% of a shrub population and 100% of the tall trees in an old-growth forest. After some time, the shrubs are much taller than those of a nearby population that was not affected by the fire. What evolutionary mechanism(s) could explain this difference?

Genetic drift and/or directional selection

What is the prevailing theory for how macromolecules assembled in the absence of enzymes?

Heat-catalyzed reactions led to the assembly of macromolecules

Adaption

Heritable trait that increases an organism's fitness

Natural selection acts on what?

Heritable traits and Phenotypes

Why is sickle-cell anemia allele more frequent in individuals of sub-Saharan African descent?

Heterozygous individuals have an advantage in sub-Saharan Africa

What influenced Darwin's ideas about the evolution of species during his journey on the surveying mission of the H.M.S. Beagle?

His experience following a major earthquake in Chile

What is true of a Cline?

It reflects genetic variation among populations

Hardy-Weinberg Principle

In a stable environment, the allele and genotype frequencies of a population will remain constant.

Which observations formed the basis of Darwin's argument for the theory of natural selection explaining descent with modification outlined in 'On the Origin of Species'?

Individuals produce more offspring than are able to survive, and they vary in heritable traits

Species are _____ and populations are ______

Individuals who can all interbreed; individuals of the same species in the same location

What is a unique property of evolution by gene flow?

It results in an increase in genetic variation

What mechanism drives natural selection?

Individuals with traits better suited to their enivornments are more likely to survive and reproduce; therefore, their offspring are more likely to inherit these adaptive traits

In his original work on natural selection, Darwin was unable to provide a mechanism to explain what?

Inheritance of traits

Both dragonflies and pigeons have wings. What insight can this fact give us about evolution?

It demonstrates that natural selection can result in similar solutions for similar needs independently

What characteristic makes it least likely that an organism will be preserved in a fossil?

It lived in a tropical rain forest

Who proposed a theory of evolution before Charles Darwin did?

Jean-Baptiste Lamarck

Which of the following population sizes (N) of bison would be most affected by genetic drift? -N=10 -N=100 -N=1000

N=10

What is the relationship between natural selection and evolution?

Natural selection is a process that results in evolution.

How is natural selection different from other modes of evolution?

Natural selection leads to the adaptation of a population to the environment

Founder Effect

Occurs when a small part of a population gets isolated from the main population and does not include all the alleles found in the main population

Natural Selection

Organisms best suited to the environment have the most resources for survival and reproduction and pass their successful traits to offspring

What type of reproductive behavior is required to maintain the Hardy-Weinberg equilibrium?

Random Mating

A new species of plant forms by allopolyploidy. The species is most likely to be maintained via what reproductive mechanisms?

Self-fertilzation

What piece of evidence supports the idea that life originated in or near submarine hydrothermal vents?

Some of the microorganisms that appear to have evolved earliest still live in hydrothermal vents

Best definition of Sympatric speciation

Speciation from a common ancestor that occurs within one geographic region

How does the Church of England's initial response to Darwin's ideas compare with their current position?

The Church was hostile to Darwin's work for many years but now accepts a scientific explanation of natural selection

The effect of single mutation in one individual on evolution is caused by

The allele can increase in frequency drastically and rapidly

Mean fitness of a population

The average of the fitness of all members of a population

How is the morphological species concept different from the phylogenetic species concept?

The morphological species concept does not rely on genetic information to differentiate between members of the same species, and the phylogenetic species concept does.

A mutation in a cichlid fish population has caused a change in mating strategy within that population. What is the most likely result of the mutation?

The mutation has affected either the color pattern of the fish or the behavior of the fish

A population of birds exhibits high diversity in alleles for feather color. Human settlers overhunt the population, causing a bottleneck effect. What might you predict about the population of birds that will exist after the bottleneck event?

The population will have less diversity in feather color because the variety of alleles will be reduced

What is continental drift?

The process in which continental plates float on the upper mantle layer of Earth and move in predictable directions

If the dinosaurs had not gone extinct, what phenomenon would have been most affected?

The rise of the mammals

Description of Darwin's 'descent with modification'

The similarities and differences between present day species and ancestral species

A labradoodle is a dog created from the mating of a Labrador retriever, known for its gentle nature, and a poodle, known for its low-shed coat. How does breeding contrast with natural selection

They are similar except that in natural selection that traits selected are always those that increase population's fitness

What does the presence of photosynthetic pigments in brown algae suggest about their evolution?

They have similar energy requirements as plants

How did photosynthetic prokaryotes dramatically change Earth's atmosphere?

They increased oxygen levels through photosynthesis

Imagine two human populations that differ in the frequency of a specific cancer gene but are otherwise genetically similar. Which of the following metrics would be the most accurate way to determine the influence of this gene on relative fitness?

Total number of children

When does a hypothesis become a theory?

When several lines of evidence and multiple experiments all independently arrive at the same conclusion

When calculating allele frequencies, what does the 'goodness of fit' statistic tell us?

Whether or not a population is evolving

Modifications of a trait by the environment during an individual's lifetime ___.

are not heritable

How have researchers encouraged longer RNA polymers to self-assemble?

by adding microscopic particles of clay

What represents a necessary condition for speciation to occur?

gametic isolation between populations

A scientist determines that two organisms are members of the same species based on the size and shape of their reproductive organs. Which species concept is this scientist using?

the morphological species concept because the scientist is comparing physical characteristics