Deck 19: Development and Evolution

Question 1

The ectodysplasin gene of stickleback fish in fresh and salt waters provides a good example of pleiotropy,because it ________.

A) affects both growth rate and bony armor of a stickleback
B) includes a DNA-binding homeodomain
C) has been duplicated repeatedly to create a whole family of variants
D) has been transferred from another organism
E) allows different populations of stickleback to interbreed

Answer 1

A

Question 2

All of the following factors can cause rapid evolutionary "jumps" except ________.

A) single alleles with major effects on life history
B) hybridization between species, producing a form that differs from both parents
C) stabilizing selection on homeotic genes
D) horizontal gene transfer between unrelated organisms
E) transposable genetic elements, or transposons

Answer 2

C

Question 3

Unlike all other honeybees,worker bees in the South African subspecies Apis mellifera capensis can lay eggs that develop asexually into queens,which makes it possible for them to "nest parasitize" other subspecies of honeybees.This is due to ________.

A) the effects of many genes integrated together (epistasis)
B) a homeotic mutation of a gene in the Hox cluster
C) the appearance of new genes that are paralogous with Hox genes
D) a deletion of nine nucleotides in the gemini transcription factor gene
E) horizontal gene transfer from a distantly related insect species

Answer 3

D

Question 4

Mutations of ________ [two words] in fruit flies can cause appendages to appear in the wrong places,such as legs growing in place of antennae.

Question 5

The discoverer of "homeotic mutations," who also resisted the growing "modern synthesis" model of evolution,was ________.

A) St. George Mivart
B) Ernst Mayr
C) Julian Huxley
D) David Wake
E) William Bateson

Question 6

The hindwing eyespots of the butterfly Bicyclus anyana responded to artificial selection for increased gold color in both or increased black color in both,but artificial selection could not produce increased gold in one spot and increased black in the other.This is an example of ________.

A) homoplasy
B) heterochrony
C) genetic linkage
D) orthologous genes
E) constraint

Question 7

François Jacob and Jacques Monod discovered ________.

A) a mechanism for how proteins regulate gene activity
B) the degree of genetic similarity between humans and chimpanzees
C) the Hox cluster of homeotic genes
D) evolutionary changes in the timing and rate of developmental processes
E) the parallel between the order of regulatory genes on a chromosome and the location in the embryo where these genes are expressed

Question 8

Libbie Hyman's comprehensive study of invertebrates,beginning in the 1940s,was noteworthy for being one of the few major works at the time to ________.

A) use Lamarckian evolution to explain the origins of animal phyla
B) use cladistics to resolve invertebrate relationships
C) integrate development with adult morphology to understand adaptation
D) propose gene regulation as an explanation for development
E) explain invertebrate evolution using "macromutations" with large effects

Question 9

Genes in the NK4 class are involved in heart development in both vertebrates and fruit flies.They are also involved in the development of pumping organs in organisms that lack a heart,such as roundworms and cnidarians.Available information suggests that in early animals,the ancestral NK4 gene and its associated regulatory network ________.

A) evolved convergently in vertebrates and arthropods
B) were important in the development of the heart and blood vessels
C) evolved by duplication of the Hox cluster
D) governed the development of some fluid-filled pumping structure
E) did not have any function

Question 10

The concept of developmental constraint may be defined as ________.

A) the sudden appearance of new phenotypes
B) homoplasy that results from the same underlying developmental mechanism
C) phenotypic similarity due to descent from a common ancestor
D) a bias toward certain kinds of variation in phenotype
E) the fact that all animals develop using the same "toolkit" of Hox genes

Question 11

A "structuralist" biologist would explain an organism's features as the result of ________.

A) natural selection acting on random, small-scale variation
B) the inheritance of traits acquired over an individual's lifetime
C) principles of mathematics and physics that determine form and function
D) major "leaps" or "jumps" in phenotype within one generation
E) divine intervention in an organism's DNA

Question 12

In early human embryos,the gene HoxB7 is involved in patterning the central nervous system.In later embryos,HoxB7 plays a critical role in growth and development of the kidney.These different functions of the same gene at different times and places are an example of ________.

A) homology
B) taphonomy
C) pleiotropy
D) unconformity
E) constraint

Question 13

The embryonic nervous systems of peanut worms (Sipuncula)and spoon worms (Echiura)show that these worms ________.

A) are descended from segmented ancestors
B) have appendages that are homologous with arthropod appendages
C) do not express Hox genes during development
D) are similar to each other because of homoplasy
E) are surprisingly closely related to vertebrates

Question 14

Why was developmental biology left out of the "modern synthesis" of evolution as it developed in the 1930s and 1940s?

A) Many developmental biologists believed that evolution progresses by rapid jumps, not slow and gradual change.
B) It was widely felt that development and genetics had to be "properly separated" for either to make any progress.
C) Many developmental biologists focused on "structuralist" explanations of evolution.
D) The genetic mechanisms of development were poorly understood at the time.
E) All of the above.

Question 15

Genes of both the ANT-C and BX-C clusters encode proteins that all include a common sequence of amino acids that interact with DNA,known as the ________.

Question 16

The most significant conclusion of the experiments on Heliconius butterfly mimics is that ________.

A) evolution can sometimes happen by sudden jumps
B) genes can occasionally be transferred between completely unrelated organisms
C) natural selection is the only mechanism for evolutionary diversification
D) the same developmental genetic mechanisms underlie a great range of variants
E) development must be studied separately from evolutionary genetics

Question 17

The simplest hypothesis for the original function of Hox genes is that the common ancestor of bilateral animals had Hox genes that were ________.

A) expressed in the development of its appendages
B) scattered throughout the genome
C) expressed in the canonical spatial pattern
D) crucial for the development of its digestive system
E) organized in multiple clusters

Question 18

Which of the following is a good example of two genes that are orthologous?

A) the promoter and the repressor genes of the lac operon in E. coli
B) the genes for the first two enzymes in the glycolytic pathway
C) the gene for the photosynthetic enzyme RuBisCO in a fern and in an oak
D) the human gene for the cell surface protein Siglec-12, and the human pseudogene Siglec-13
E) None of these pairs are orthologous.

Question 19

According to a database kept by the HUGO Gene Nomenclature Committee,there are currently six genes in the human genome for different variants of the protein collagen IV.Assuming that all these genes are derived from an ancestral gene,the most precise term for these genes would be ________.

A) homeotic
B) paralogous
C) transcription factors
D) structural
E) orthologous

Question 20

Evolutionary shifts in the relative rates and timing of developmental events are known as ________.

Question 21

When selection increases one feature of an organism at the expense of another,we speak of an evolutionary ________.

Question 22

Despite a great deal of variation across the animal kingdom,Hox genes tend to appear along a chromosome or chromosomes in the same order that they are expressed in along the anteroposterior axis of an embryo.This pattern of Hox gene expression is called the ________.[four words]

Question 23

A ________ is one who believes that major evolutionary change happens,or can happen,by large "jumps" or bursts,such as mutations with large effects.

Question 24

Australian marsupials known as flying phalangers (genus Petaurus),southeast Asian mammals known as colugos (order Dermoptera),and North American flying squirrels (genus Glaucomys)are not closely related,but all three have furry membranes extending from wrist to ankle that enable them to glide from tree to tree.Explain how you could decide whether these similarities are due to convergence or to parallel evolution.

Question 25

In 1996,Michael Behe argued that the bacterial flagellum (a rotating filament-like structure that enables a bacterium to swim)could not have evolved by natural selection,since it is made up of many integrated parts (proteins),and the absence of any one of those parts would make the entire structure useless.Outline a set of experiments on flagella that would test the alternate hypothesis that flagella evolved through exaptation at the molecular level.

Question 26

South American anteaters have no teeth and a long sticky tongue; they rip open anthills and termite mounds and capture insects with their tongues.An Australian marsupial known as the numbat (Myrmecobius fasciatus)is not closely related to anteaters,but it too has highly reduced teeth and a long sticky tongue,and it feeds by ripping open termite burrows and lapping the insects up.Such similarities between species that are not inherited from a common ancestor are known as ________.

Question 27

The simplest hypothesis for the original function of Hox genes is that they were expressed in the ________ [two words] in early animals.

Question 28

At the end of the chapter,the text points out that almost all our knowledge of evo-devo is based on plants and animals; we know little about other complex multicellular organisms that undergo development.Consider a mushroom,a member of the Kingdom Fungi.Based on what you know of its structure and mode of growth,would you predict that it would have orthologous genes to the Hox genes of animals? Explain why or why not.

Question 29

The eighteenth-century French scientist Étienne Geoffroy Saint-Hilaire argued for a far-reaching concept of what we would now call homology.For example,he argued that the vertebrae and ribs of vertebrates are fundamentally the same structures,built on the same plan,as the segmented exoskeleton and legs of insects and other arthropods.Insects,according to Geoffroy Saint-Hilaire,quite literally live inside their vertebrae and walk on their ribs.His idea is not really true in the sense that he conceived it―and yet,in the light of discoveries about Hox genes and developmental regulation,some modern evolutionary biologists have had good things to say about Geoffroy Saint-Hilaire's work.(See "Brotherhood by Inversion" in Stephen Jay Gould's book Leonardo's Mountain of Clams and the Diet of Worms,for example.)Explain why a modern "evo-devo" specialist might find Geoffroy Saint-Hilaire's ideas worth revisiting in the light of current knowledge.

Question 30

The evolutionary conversion of a structure,gene,or gene complex from one function to another was called ________ by Stephen Jay Gould and Elisabeth Vrba.