Biology Chapter 13 & 14

Fresh assortments of existing alleles arise every generation from three random components of sexual reproduction

-independent orientation of homologous chromosomes at metaphase I of meiosis, -crossing over -random fertilization

Three-domain system

-two domains of prokaryotes (Bacteria and Archaea) and -one domain of eukaryotes (Eukarya)

Two Parts of a Binomial

1) Genus (plural general), a group of closely related species 2) Second part of binomial is used to distinguish species within a genus

Two distinct forms of polyploid speciation

1) polyploidy arises from a single parent species. A failure of cell division might double the chromosome number from the original diploid number (2n) to tetraploid (4n). 2) can occur when two different species interbreed and produce hybrid offspring

Population

A group of individuals that belong to the same species and live in the same area and interbreed

_____________________ that delete, disrupt, or rearrange many gene loci at once are almost certain to be harmful

Chromosomal mutations

__________________ has had a tremendous impact on the evolution of life's diversity by -reshaping the physical features of the planet and -altering the environments in which organisms live.

Continental drift

Where would a genetic mutation first appear?

DNA

All forms of life use the same genetic language of _____ & _____

DNA and RNA

Natural Selection

Darwin proposed a scientific mechanism for how life evolves, -individuals with certain inherited traits are more likely to survive and reproduce than are individuals with other traits.

True or false? When a population separates and forms two distinct species in the absence of a geographical barrier this is known as allopatric speciation

False

Darwin is known for his work studying which species?

Finches

Evidence of evolution includes...... (3)

Fossils, DNA analysis/molecular studies, homologous structures/comparative anatomy

What is another source of evolutionary change that is genetic exchange with another population?

Gene flow

At the population level, biologists focus on the ___________, which consists of all copies of every type of allele, at every locus, in all members of the population

Gene pool

Darwin's voyage was on the __________

HMS Beagle

Which is the most inclusive category among the following is __________ species order kingdom phylum genus

Kingdom

__________ proposed that species evolved by the inheritance of characteristics acquired by their parents

Lamarck

__________ proposed that geological processes are still ongoing

Lyell

The emergence of very diverse species of house pets (such as different types of birds) is an example of __________.

Macroevolution

A species is a distinct group of organisms with a unique set of characteristics based on the way they look. This is known as ___________

Morphological species concept

Which process causes the appearance of new alleles in a population?

Mutation

The Darwin-Wallace theory of evolution by natural selection did not include which of the following -Individual variation -Organisms that are driven to become perfect -Differential (unequal) reproductive success -Overabundance of organisms

Organisms that are driven to become perfect

Which of the following provides an explanation for the distribution of fossils?

Plate tectonics

Duplication of a gene or small pieces of DNA through errors in meiosis can

Provide an important source of genetic variation and eventually lead to new genes with novel functions

Homology

Similarity resulting from common ancestry

The average birth weight of human babies has remained within the range of approximately 6.5 to 9 lbs. over many generations. This is the result of __________

Stabilizing selection

__________________ includes taxonomy, focusing on classifying organisms and determining their evolutionary relationships

Systematics

Allopatric Speciation

The initial block to gene flow is a geographic barrier that physically isolates the splinter population

Genetic drift

a change in the gene pool of a small population due to chance

Sexual dimorphism

a distinction in appearance between males and females not directly associated with reproduction or survival

Sexual selection

a form of natural selection in which individuals with certain traits are more likely than other individuals to obtain mates

Phenylketonuria (PKU)

a recessive allele that prevents the breakdown of the amino acid phenylalanine and occurs in about one out of every 10,000 babies born in the United States

Polyploidy

a species may originate from an accident during cell division that results in an extra set of chromosomes, habitat complexity, and sexual selection

The bottleneck effect

an example of genetic drift. It results from a drastic reduction in population size decreases the overall genetic variability in a population, because at least some alleles are lost from the gene pool, and results in a loss of individual variation and hence adaptability.

Reproductive barrier

anything that prevents individuals of closely related species from interbreeding

The biological species concept fails to recognize species of __________

bacteria

Two individuals from different populations attempt to mate but are unable to successfully coordinate the mating dance. This is an example of a __________ isolating mechanism.

behavioral

Taxonomy

branch of biology concerned with identifying, naming, and classifying species

Disruptive selection

can lead to a balance between two or more contrasting phenotypic forms in a population

Relative fitness

contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

Geologic Time Scale

divides Earth's history into a consistent sequence of geologic periods

natural selection resulted in diverse modifications, or ___________ that fit them to specific ways of life in their environment

evolutionary adaptations

Stabilizing selection

favors intermediate phenotypes, occurs in relatively stable environments, and is the most common

Hardy-Weinberg theorem

frequency of the recessive phenotype is q2, where q is the frequency of the recessive allele Example: If the recessive allele frequency (represented by q) is equal to 0.4 and the dominant allele frequency (p) is 0.6 (or 1-0.4), then the frequency of the recessive phenotype (q2), or 0.4 x 0.4, equals 0.16.

Fossils

imprints or remains of organisms that lived in the past

Convergent evolution

involves superficially similar structures from different evolutionary branches that result from natural selection shaping analogous adaptations

Mutation

is the ultimate source of the genetic variation that serves as raw material for evolution

The Linnaean System

method of naming species and a hierarchical classification of species into broader groups of organisms. Introduced a system for grouping species into a hierarchy of categories

•Advances in ____________ provide a much deeper understanding of homologies. The evolutionary history of each species is documented in the DNA inherited from its ancestral species. -If two species have homologous genes with sequences that match closely, biologists conclude that these sequences must have been inherited from a relatively recent common ancestor. -Conversely, the greater the number of sequence differences between species, the more distant is their last common ancestor.

molecular biology

Continental Drift

movements in the mantle cause the plates to move

The three main causes of evolutionary change are

natural selection, genetic drift, gene flow

Postzygotic barriers

operate if interspecies mating occurs and hybrid zygotes form

Prezygotic barriers

prevent mating or fertilization between species

The most common method geologists use to learn the ages of rocks and the fossils they contain is ______________ a method based on the decay of radioactive isotopes

radiometric dating

Vestigial structures

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.

Vestigial Structures

remnants of features that served important functions in an organism's ancestors

Directional selection

shifts the overall makeup of a population by selecting in favor of one extreme phenotype

The correct order, from least to most inclusive, of the classification categories is __________

species, genus, family, order, class, phylum, kingdom, domain

Theory of Plate Tectonics

the continents and seafloors form a thin outer layer of solid rock, called the crust, divided into giant, irregularly shaped plates that float atop the mantle, a mass of hot, viscous material

Younger strata are on top of older layers, the relative ages of fossils can be determined by........

the layer in which they are found

Fossil Record

the ordered sequence of fossils as they appear in the rock layers, marking the passage of geologic time

Artificial Selection

the selective breeding of domesticated plants and animals to promote the occurrence of desirable traits in the offspring

Biogeography

the study of the past and present distribution of organisms

In organisms that reproduce sexually, most genetic variation in a population results from

the unique combination of alleles that each individual inherits.

Sympatric Speciation

without geographic isolation

Biological species concept defines a species as

"a group of populations whose members have the potential to interbreed with one another in nature and produce fertile offspring (offspring that can reproduce)." The biological species concept cannot be applied in all situations, including asexual organisms and fossils.

Gene Flow

-Another source of evolutionary change -Genetic exchange with another population -May result in the gain or loss of alleles -Tends to reduce genetic differences between populations.

Darwin learned that artificial selection has two essential components:

1.variation among individuals and 2.heritability, the transmission of a trait from parent to offspring

Clade

An ancestral species and all of its evolutionary descendants

Similarity due to convergence is called ______, not homology.

Analogy

What type of supportive evidence for evolution has been obtained from comparing the forelimbs of different mammals?

Anatomical homology

Which domains identify organisms that have prokaryotic cells?

Archaea and Bacteria

In the Linnaean system, each species is given a two-part Latinized name

Binomial

-scientists regard Darwin's concept of evolution by means of natural selection as a __________ a widely accepted explanatory idea that -is broader in scope than a hypothesis, -generates new hypotheses, and is supported by a large body of evidence

Theory

True or False? Convergent evolution is where some species have similar anatomical structures due to similar environments and not a common ancestor

True

Anatomical structures such as the tailbones of humans are not critical to survival but may be very important to other animals, such as our primate relatives. In humans, the tailbone could be considered __________

Vestigial