Bio II: Chapters 18 - 21 (Test 1)

What idea is shared by both Lamarck's and Darwin's theories of evolution?

Environmental changes can lead to the modification of traits.

Stabilizing selection:

Favors the survival of individuals with intermediate phenotypes Extreme values of a trait are selected against

Disruptive/Diversifying selection:

Favors the survival of two or more different genotypes that produce different phenotypes Likely to occur in populations that occupy heterogeneous environments

Biogeography:

Field of study that uses geographic distribution of extinct and living species to determine patterns of evolution.

Evidence of Evolution: Extinct/living members of the horse family.

Fossil record

The Deep-Sea Vent Hypothesis relies on the chemical reaction between ____ and ____ for the build up of an H2 concentration gradient to provide energy for the reduction of N2 to NH3?

H2S (hydrogen sulfide) and Fe (iron)

What eon preceded organisms?

Hadean

Four eons (in order):

Hadean, Archaean, Proterozoic, Phanerozoic

Directional selection:

Individuals at one extreme of a phenotypic range have greater reproductive success in a particular environment.

How does the phenomenon of horizontal gene transfer muddle the concept of monophyletic groups?

Monophyletic groups are based on the concept that a particular group of species descended from a common ancestor. When horizontal gene transfer occurs, not all of the genes in a species were inherited from the common ancestor.

Allopatric speciation:

Most prevalent method for cladogenesis Occurs when some members of a species become geographically separated

Sympatric speciation:

Occurs when members of a species that are within the same range diverge into two or more different species even though there are no physical barriers to interbreeding

If two genes are homologous, then it can be said that they are derived from:

the same ancestral gene.

Taxonomy:

the science of describing, naming, and classifying extant and extinct organisms.

Sequence of the four overlapping stages of life:

Prebiotic production of nucleotides and amino acids Polymerization into larger molecules Polymers became enclosed in membranes Polymers enclosed in membranes acquired cellular properties

Paraphyletic groups: Polyphyletic groups:

When taxa are constructed with descendants missing. When taxa are constructed with ancestors missing and species from different lineages are grouped.

Hox genes in mammals determine:

cell fate along the anteroposterior axis.

BMP4 is expressed similar in both chicken feet and duck feet, while gremlin is not expressed between the toes of _______.

chicken feet

What three distinct organelles is genetic material (DNA and RNA) found in within eukaryotic cells?

chloroplast, mitochondria, and nucleus.

A mutation arises in an individual that decreases its fitness. This means that this individual's contribution to the gene pool of the next generation will ______.

decrease

Evidence of Evolution: Darwin's finches.

Biogeography

Evidence of Evolution: Endemic island species.

Biogeography

Allele frequency =

# copies of specific all in a population / total # all alleles for that gene in a population

Genotype frequency =

# individual with a particular genotype in a population / total # individuals in a population

In the Hardy-Weinberg equation, p + q =__, where p and q represent _________.

1 allele frequencies

If a population satisfies the Hardy-Weinberg equilibrium model, what can you assume about that population?

Allele and genotype frequencies are stable.

Explain the relationship between number of Hox genes and animal body complexity.

An increase in the number of Hox genes allows for greater specialization in different body regions.

Factors that affect the fossil record:

Anatomy, size, number, environment, time, geological processes, and paleontology.

During which eon did life emerge?

Archaean

Scientists agree that mitochondria were acquired through endosymbiosis before chloroplasts. Why?

Because all eukaryotes have mitochondria, but only plants and some algae have chloroplasts.

Why are marine species more likely to be preserved than inland species?

Because sedimentary rock is generally formed in or near water.

Coacervates:

Droplets that form spontaneously from the association of charged polymers Catalysts trapped inside can perform primitive metabolic functions

Convergent evolution:

Characteristics of different species that look or function similarly although the organisms are not closely related.

Principle of parsimony:

Cladistic approach discriminates among possible trees by considering the various possible pathways of changes and then choosing the tree that requires the least complicated explanation.

Evidence of Evolution: Wings of butterflies and birds / Camera eyes of squids and humans.

Covergent evolution

Sexual selection:

Directed at certain traits of sexually reproducing species that make it more likely for individuals to find or choose a mate and/or engage in successful mating Usually affects male characteristics more than females

Order of grouping of organisms:

Domain - Supergroup - Kingdom - Phylum - Class - Order - Family - Genus - Species (Damn straight, keep pond clean or froggy gets sick.)

What phenomenon tends to increase genetic variation in a population, while also tending to decrease the genetic variation among populations?

Gene flow

Orthologous:

Gene loci that are homologous because of a lineage-splitting event (speciation).

Paralogous:

Gene loci that originated by a duplication event within a lineage.

Correct species name for humans:

Homo sapiens

Evidence of Evolution: Gill ridges in human and fish embryos.

Homology

Evidence of Evolution: Mouthparts of different insects.

Homology

Names of the two supercontinents that existed:

Laurasia and Gondwana

Balancing selection:

Maintains genetic diversity

Endemic:

Naturally found only in a particular location.

Conditions for Hardy-Weinberg Equilibrium:

No new mutations occur No natural selection occurs The population is so large that allele frequencies do not change due to random sampling error No migration occurs between different populations Random mating

Motoo Kimura's neutral theory of evolution: Are neutral mutations subject to sexual selection?

No.

The first macromolecule found in protobionts, due to its ability to store information, catalyze chemical reactions, and potential for self-replication:

RNA

Evidence of Evolution: Kale, broccoli, and cabbage / Different types of cattle.

Selective breeding

What period did not end coincident with a major mass extinction event?

Silurian

Systematics:

The study of biological diversity and evolutionary relationships among organisms.

What is needed for natural selection to occur?

Variation in traits Differential reproduction Traits that can be passed from parent to offspring

Liposomes:

Vesicles surrounded by a lipid layer Clay can catalyst formation of liposomes that grow and divide Can enclose RNA

Anagenesis:

When a species consisting of a single large population slowly evolves over many generations into a new species.

When populations are reduced following a major disaster, the resulting random change in allele frequencies is called the:

bottleneck effect.

A critical characteristic of a protobiont that is found in both modern day prokaryotes and eukaryotes is:

a boundary membrane that separates external from internal environments.

Chemical selection occurs when:

a chemical within a mixture increases in number compared to other chemicals in the mixture due to a unique property.

The effect of inbreeding is:

a decrease of heterozygotes in succeeding generations.

Genetic drift can lead to the fixation of an:

allele.

The first living cells were most likely:

anaerobic, heterotrophic, and prokaryotic.

In eukaryotes, genes involved in transcription and translation are derived from:

archaeal ancestors.

Microevolution:

at minimum, changes in frequency in a single gene (allele) in a population over generations.

The function of BMP4 is to ____________ while the function of gremlin is to __________ BMP4.

cause apoptosis inhibit the function of

Evolutionary developmental biology:

compares the development of organisms in order to better understand mechanisms of evolutionary change.

"Transitional form" fossil:

contains some of the traits of its ancestors and some of the traits of its descendants

The event called the Cambrian Explosion resulted in an abrupt increase in:

diversity of major animal groups.

According to the principle of parsimony, a tree is the more likely choice because it requires [few / many] mutations.

few

When a few individuals colonize a new location, the subsequent random change in allele frequencies is called the:

founder effect.

Motoo Kimura's neutral theory of evolution: Neutral mutations can spread throughout a population via _______________.

genetic drift

The random change in allele frequencies is called:

genetic drift.

The phenomenon in which one region of the body grows faster than another among different species is called:

heterochrony.

Fossils are primarily found in _______ rocks.

igneous.

Changes that have occurred in living organisms over the past four billion years are due primarily to:

interaction of genetic and environmental changes.

Stromatolites:

layered structure of cyanobacteria and calcium carbonate, both living and fossilized.

Organisms that reproduce by asexual reproduction and have low DNA replication error rates are the ____ likely to experience adaptation.

least

With the bottleneck effect, if populations return to its pre-disturbance size, genetic variation is generally ______ than in the original population.

lower

Genetic drift:

mechanism that leads to changes in allele frequencies due to random sampling basis.

A branching point in a phylogenetic tree is called a _________; it illustrates that _______ has occurred.

node cladogenesis

The major opposition to the Extraterrestrial Hypothesis is:

most organic carbon molecules, including nucleic acids and amino acids, would have been destroyed by the intense heating that occurs when large bodies fall through the Earth's atmosphere.

Sources of new genetic variation:

mutations within genes gene duplication horizontal gene transfer

Mechanisms that alter existing genetic variation:

natural selection genetic drift migration nonrandom mating

Motoo Kimura suggested that most genetic variation in a population is due to ______ rather than ______ variation.

neutral adaptive

Molecular clocks are based primarily on the rates of:

neutral mutations.

What are the two principal factors that lead to microevolution?

new genetic variation and evolutionary mechanisms

An important message from the work of Thomas Malthus that influenced Charles Darwin was:

only a fraction of any population will survive and reproduce.

Hardy-Weinberg equation:

p2 + 2pq + q2 = 1 p2: genotype frequency of homozygotes for one allele 2pq: genotype frequency of heterozygotes q2: genotype frequency of homozygotes for another allele

Fitness is a measure of the _______ of a particular genotype in a population.

reproductive success

Motoo Kimura's neutral theory of evolution: Neutral mutations do not affect __________ and therefore cannot alter evolutionary fitness.

reproductive success

Symplesiomorphy:

shared "primitive" (ancestral) homologous character originating prior to the most recent common ancestor of a group of species, from a common ancestor more ancient than the most recent common ancestor

Synapomorphy:

shared derived homologous character originating with the most recent common ancestor of a group of species.

Macroevolution:

the process of evolutionary changes that result in the formation of new species.

Ecological species concept:

species are identified based on their unique habitat requirements.

The chemical composition of the gases surrounding the Earth has changed substantially over the past 4 billion years. One notable change was due to:

the emergence of photosynthetic organisms, since the process of photosynthesis increased the amount of oxygen in the atmosphere.

Phylogeny:

the evolutionary history of a species or group of species.

Protobionts:

the first nonliving structures that evolved into living cells uses prebiotically created monomers.

An important shift in thought that preceded Darwin's development of evolutionary theory was:

the increased acceptance of evidence of uniformitarianism in the field of geology.

The idea that most of the genetic variation found in populations is not subject to natural selection is the basis of:

the neutral theory of evolution.

A disadvantage of using DNA or RNA sequences to identify species is that:

there is no rule for determining the number of sequence differences needed for a new species.

The oldest fossils that have been found date back how far?

~3.5 billion years.