analogy
-think analogous -critical in reconstructing phylogenies -no common ancestry
binomial
-Linnaeus instituted a two-part format for Latin scientific names -italicized -consists of the genus name and the specific epithet
clade
-includes an ancestral species and all of its descendants
cladistics
-approach to systematics -common ancestry is the primary criterion used to classify organisms -place species into groups called clades
cladogram
.
class
-between order and phylum
character
-can be ancestral or derived -shared characteristics between organisms
domain
-Bacteria, Eukarya, Archaea
family
-above genus
genus
-first part of a binomial -(plural) genera -before species
homologies
-similarity in characteristics resulting from a shared ancestry
homologous genes
.
homoplasy
-a similar (analogous) structure or molecular sequence that has evolved independently in two species
homoplasies
- a similar (analogous) structure or molecular sequence that has evolved independently in two species
ingroup
-a species or group of species whose evolutionary relationships we seek to determine
kingdom
- taxonomic category, second broadest after domain
maximum liklihood
-given certain probability rules about how DNA sequences change over time
maximum parsimony
-should first investigate the simplest explanation that is consistent with the facts -p544 online
molecular systematics
-discipline that uses data from DNA and other molecules to determine evolutionary relationships p542 online
monophyletic group (clade)
-group of species and their common ancestor -"single tribe"
order
.
orthologous genes
.
outgroup
-species or group of species from an evolutionary lineage that is known to have diverged
paralogous genes
.
paraphyletic group
-consists if ancestral species and some of its descendants, but not all of them -"beside the tribe" -p543 online
phylogenetic tree
.
polyphyletic
-some members have different ancestors -"many tribes"
shared ancestral
-a character, shared by members of a particular clade, that originated in an ancestor that is not a member of that clade -originated in the ancestor of the taxon -example: a mammal's backbone
shared derived
-an evolutionary novelty that is unique to a particular clade -example: a mammal's hair which is not found in ancestors
specific epithet
-unique for each species within the genus -second part of a binomial
taxon
-(plural) taxa -a named taxonomic unit at any given level of classification
Distinguish between taxonomy, systematics and phylogeny.
.
Explain why it is crucial to distinguish between homology and analogy before selecting characters to use in the reconstruction of phylogeny.
.
Explain why bird and bat wings are homologous as vertebrate forelimbs but analogous as wings.
.
Describe several reasons using common names can be problematic (in class notes)
.
Explain the following characteristics of the Linnaean system of classification: a. binomial nomenclature b.hierarchial classification
.
List the major taxonomic categories from most to least inclusive.
.
Define a clade
.
Distinguish between a monophyletic clade paraphyletic and polyphyletic grouping of species.
.
Distinguish between shared primitive characters and shared derived characters.
.
Explain how shared derived characters can be used to construct a phylogenetic diagram.
.
Explain how outgroup comparison can be used to distinguish between shared ancestral characters and shared derived characters.
.
Discuss how systematists use the principles of maximum parsimony and maximum likelihood in reconstructing phylogenies.
.
Explain why any phylogenetic diagram represents a hypothesis about evolutionary relationships among organisms.
.
Distinguish between orthologousand paralogous genes.
.
Explain how gene duplication has led to families of paralogous genes
.
Linnaean classification mnemonic device
King Philip Cut Open Five Green Snakes. Kingdom, Phylum, Class, Order, Family, Genus, Species.
Chapter 26 Assignment
.
Prokaryotic cells are found in the domain(s) _____. A) Bacteria and Archaea B) Bacteria and Eukarya C) Bacteria and Protista D) Bacteria E) Protista and Archaea
Bacteria and Archaea
In the five-kingdom system, prokaryotes are placed in the kingdom _____. Protista Animalia Fungi Plantae Monera
Monera
A human is classified in domain _____ and kingdom _____. Eukarya ... Fungi Eukarya ... Protista Eukarya ... Plantae Eukarya ... Animalia Bacteria ... Archaea
Eukarya ... Animalia
A rose bush is classified in domain _____ and kingdom _____. A) Eukarya ... Fungi B) Eukarya ... Protista C) Eukarya ... Plantae D) Eukarya ... Animalia E) Bacteria ... Archaea
C) Eukarya ... Plantae
In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes? A) Fungi B) Protista C) Plantae D) Animalia E) Monera
E) Monera
In the two-kingdom system, why were fungi classified in the kingdom Plantae? A) They are sedentary. B) They are heterotrophs. C) They lack cell walls. D) They are unicellular. E) They are autotrophs.
A) They are sedentary.
There is(are) _____ eukaryotic domain(s). A) one B) two C) three D) four E) five
A) one
Quiz Content
.
Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that includes species T, X, Y, and Z makes up A) a polyphyletic grouping. B) an ingroup, with species U as the outgroup. C) a monophyletic clade. D) a paraphyletic grouping. E) a valid taxon.
D) a paraphyletic grouping.
In a comparison of birds with mammals, having four appendages is A) a shared ancestral character. B) a character useful for sorting bird species. C) an example of analogy rather than homology. D) a shared derived character. E) a character useful for distinguishing birds from mammals.
A) a shared ancestral character
If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup? A) domestic cat B) lion C) wolf D) tiger E) leopard
C) wolf
The relative lengths of the amphibian and mouse branches in the phylogeny in the figure above indicate that A) amphibians evolved before mice. B) mice evolved before amphibians. C) the genes of amphibians and mice have only coincidental homoplasies. D) the homologous gene has evolved more rapidly in mice. E) the homologous gene has evolved more slowly in mice.
E) the homologous gene has evolved more slowly in mice.
To apply parsimony to constructing a phylogenetic tree, A) choose the tree in which the branch points are based on as many shared derived characters as possible. B) choose the tree with the fewest branch points. C) choose the tree that assumes all evolutionary changes are equally probable. D) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology. E) base phylogenetic trees only on the fossil record, as this provides the simplest explanation for evolution.
D) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology.
Which of the following taxonomic categories contains all the others listed here? (Concept 26.1) A) genus B) species C) order D) family E) class
E) class
Animals that possess homologous structures probably _____. (Concept 26.2) A) are not related B) have increased genetic diversity C) by chance had similar mutations in the past D) evolved from the same ancestor E) are headed for extinction
D) evolved from the same ancestor
Systematists have used a wide variety of traits to reconstruct the phylogenies of particular groups of organisms. Which one of the following traits produces the best estimate of the true phylogeny? (Concept 26.2) A) gross morphological traits B) molecular traits C) behavioral traits D) biochemical traits E) all of the above traits combined
E) all of the above traits combined
By definition a clade is _____. (Concept 26.3) A) analogous B) Monophyletic C) paraphyletic D) polyphyletic E) parsimonious
B) Monophyletic
Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character? (Concept 26.3) A) Cladistic character B) Polyphyletic character C) Analogous character D) Shared ancestral character. E) Shared derived character
D) Shared ancestral character.
What process actually increases the number of genes in an organism's genome? (Concept 26.4) A) Mutation B) Parsimony C) Gene duplication D) Cladistics E) All of the above.
C) gene duplication
Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago? (Concept 26.4) A) rRNA is traditionally the nucleic acid chosen for recent comparisons. B) DNA coding for rRNA changes relatively slowly. C) rRNA mutates rapidly. D) rRNA cannot mutate. E) rRNA is never the nucleic acid chosen for comparisons.
B) DNA coding for rRNA changes relatively slowly.
Molecular clocks are based on the idea that _____. (Concept 26.5) A) Molecules resonate at a certain frequency that can be measured. B) Advantageous mutations arise at a constant rate. C) Directional selection occurs at a constant rate. D) Mutations occur once every generation. E) On average neutral mutations arise at a constant rate.
E) On average neutral mutations arise at a constant rate (The idea of a molecular clock rests on the assumption that neutral mutations can arise and become fixed in populations. The rate of occurrence of these mutations is not affected by natural selection, so it is assumed that the rate is relatively constant over time.)
The domains of life are _____. (Concept 26.6)
Archaea, Bacteria, Eukarya
What process has clearly been involved in producing the tree/bush/ring of life? (Concept 26.6) A) Horizontal gene transfer B) mitosis C) phylogenetics D) artificial selection E) taxonomy
A) Horizontal gene transfer
Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult? A) mitosis B) meiosis C) binary fission D) horizontal gene transfer E) alternative RNA splicing
D) horizontal gene transfer (Horizontal gene transfer permits gene flow from one organism's genome to another organism's genome, It occurs commonly between prokaryotes of different species, and even between prokaryotes and eukaryotes.)
Which observation supports the position of eukaryotes at the convergence of the "ring of life"? A) Only eukaryotes perform mitosis. B) The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. C) Eukaryotes and archaeans both lack peptidoglycan in their cell walls. D) Circular chromosomes are present in both bacteria and archaeans. E) Introns are rare in both bacteria and archaeans.
B) The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. (A leading hypothesis proposes that eukaryotes are the result of fusion involving a bacterium and an archaean, thereby explaining the presence of both kinds of genes.)
In Figure 26.4 in your textbook, which similarly inclusive taxon descended from the same common ancestor as Canidae?
Mustelidae
Select the correct statement about phylogenetic trees. A) Phylogenetic trees may expand quickly to maximum width and then narrow over time. B) Phylogenetic trees always show increased branching, representing increased diversity over time. C) All phylogenetic trees are similarly shaped.
A) Phylogenetic trees may expand quickly to maximum width and then narrow over time. (There is considerable variation in the form of phylogenetic trees. Some expand quickly to maximum width. Some become tapered through time as most branches become extinct and only a few diversify. Some show rapid and early diversification, and maintain this width by balance of extinction and speciation. Read about phylogenetic trees.)
Which of these are homologous structures? A) Plant root and plant leaf B) There are no homologous plant structures. C) Ivy leaf and pine needle
Ivy leaf and pine needle (The leaves of all living plants evolved from leaves of early plants. There are many homologous plant structures. For instance, all plant leaves and modified leaves (such as thorns and tendrils) are homologous structures derived from the leaves of early plants. Read about homology.)
Phylogeny is the evolutionary history of related groups of organisms. Organisms are grouped into taxa based on homologous characteristics, shared traits that result from common ancestry. Which statement is true? A) Homologous structures look the same and serve the same function, but they differ in evolutionary origin and structure. B) The term "monophyletic" refers to a taxon that includes an ancestral species and all of its descendants. C) Ancestral traits are always simpler than derived traits.
B) The term "monophyletic" refers to a taxon that includes an ancestral species and all of its descendants.