Biology Test 2 Wood

Researchers use different approaches to interpret/filter different trees Different types of data may show different group patterns

parsimony (least # of changes); evolutionary distance or maximum likelihood/Bayesian analyses

Which species concept uses reproductive isolation as the primary criterion for identifying species?

Biological species concept

Which species concept would be most useful to a team of biology students conducting a biodiversity survey on their campus?

The morphospecies concept

Peter and Rosemary Grant observed a small group of large ground finches colonize the island of Daphne Major in the Galápagos Islands. Within a few years, the descendants of the colonists had evolved beaks that were much larger than those in the original source population. What factors did the Grants think influenced this evolutionary change?

The original small size of the colonist pool probably resulted in divergence from the parent population of large ground finches due to founder effects and genetic drift; natural selection favored large beak size due to the larger seeds found on Daphne Major.

True or False: Speciation via polyploidy is a rapid event.

True

True or false? A flood that separates a population of frogs onto opposite sides of a lake is an example of a vicariance event that may result in allopatric speciation.

True

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

A behavioral reproductive isolating mechanism

What is genetic drift?

A change in allele frequencies caused by random events

Upon formation, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

A variety of empty ecological niches, leading to adaptive radiation

the rapid production of many descendant species from a single lineage

Adaptive radiation

Speciation that begins with geographic isolation is known as

Allopatric speciation

The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and ________.

An increasing number of viable, fertile hybrids is produced over the course of the next 100 generations

Which of the following events could be described as a case of speciation in sympatry? Speciation cannot take place in sympatry, only in allopatry, where geography poses a barrier to gene flow. A new, isolated population of fruit flies is founded by a small group of colonists, which then diverge from the ancestral source population. An individual plant undergoes meiotic failure, producing diploid pollen and ovules; these self-fertilize, germinate, and grow into several fully fertile tetraploid plants. A population of lizards is subdivided by a natural barrier and subsequently diverges to form two species that cannot interbreed.

An individual plant undergoes meiotic failure, producing diploid pollen and ovules; these self-fertilize, germinate, and grow into several fully fertile tetraploid plants.

Why are animals less likely than plants to speciate by polyploidy?

Animals self-fertilize less often than plants, so diploid gametes are less likely to fuse.

Which of the following events may be the first step in sympatric speciation but not in allopatric speciation? Dispersal Autopolyploidy Natural selection Vicariance

Autopolyploidy

a population or group of the population that do not interbreed or fail to produce viable, fertile, offspring after mating

Biological Species Concept

is the lower, average rate of extinction reduces certain populations to zero due to: Normal environmental change Emerging disease Predation pressure Competition with other species

Background extinctions

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

Behavioral isolation

Study of how species and populations are distributed geographically. Can inform allopatric speciation

Biogeography

Animals became larger, more diverse and more complex Linked to: Higher O2 levels Increase in algae Predation drove selection of protection (e.g. shells, movement) New niches New genes (HOX genes)

Cambrian Explosion (540 MYA)

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and competition is an example of

Convergent evolution

A character or trait is any genetic, morphological, physiological, developmental, or behavioral characteristic to be studied Each character has two possible states: present (1) or absent (0)

Data matrix

Which of the following represents a vicariance event that may lead to speciation? A small subset of individuals in a population of mainland birds leaves and starts a new population on a small neighboring island. Some individuals in a population of flightless insects colonize a new food plant that has dispersed into the same geographic areas as the insect population. The insects that feed on this new food source no longer interact or interbreed with individuals from the original population. During a strong storm, a river changes course and flows through a population of ground beetles; the river is now a barrier preventing contact between the populations on either side of the river. In a population of beetles, a group of beetles colonizes a new region.

During a strong storm, a river changes course and flows through a population of ground beetles; the river is now a barrier preventing contact between the populations on either side of the river.

one species goes extinct

Extinction

ecological opportunity

Extrinsic Factors

True or false? The last ice age produced many different species mainly because populations dispersed and colonized new habitats.

False, the last ice age produced many different species mainly because of vicariance events; the glaciers physically separated populations from each other.

What evidence provides the best support for the identification of three species of elephants? Offspring from hybridization of forest and savanna elephants have been born and survived. Forest and savanna elephants have distinct genetic profiles, even when they live in close proximity to each other. Forest and savanna elephants live in different habitats and rarely interact. Hybrid offspring from mating of Asian and African elephants do not survive to adulthood.

Forest and savanna elephants have distinct genetic profiles, even when they live in close proximity to each other.

Provides direct evidence about what organisms in the past looked like, where/when they lived Limitations include: habitat bias, tissue bias, temporal bias and abundance bias

Fossil Record

separate groups interbreed (increasing gene flow)

Fusion

What Happens When Isolated Populations Come into Contact?

Fusion & (Potential) Extinction Reinforcement of divergence Hybrid zone New species

Which of the following does not tend to promote speciation?

Gene flow

happens when populations become geographically separated.

Geographic isolation

Which event could be the first step in allopatric speciation? A flood separates two groups of frogs from a population, keeping them on opposite sides of the flooded area for a few months. Glaciation during the Pleistocene Epoch, separating east and west coast populations of a bird species Development of different antler sizes between male and female reindeer Migration of birds back and forth between the mainland and an island

Glaciation during the Pleistocene Epoch, separating east and west coast populations of a bird species

common ancestry

Homology

independent evolution of similar traits in distantly related organisms Occurs when there are adaptations to similar environmental pressures

Homoplasy

Which mechanism of reproductive isolation causes postzygotic isolation?

Hybrid sterility

a geographic area where interbreeding occurs and hybrids are common

Hybrid zone

A population of birds colonizes an area in which the insects upon which they feed live inside trees. Which of the following events accounts for an observed increase in average beak size in the bird population over time? Decreased fitness of small-beaked birds, creating a new species Increased fitness of large-beaked birds, leading to natural selection Decreased fitness of the insects, allowing the birds to catch them more easily Increased fitness of the large-beaked birds, creating a new species

Increased fitness of large-beaked birds, leading to natural selection

evolution of key morphological/physiological/ behavior traits

Intrinsic Factors

What is the disadvantage of the Morphological species concept?

It is very difficult to determine whether morphological differences among fossils represented normal variation within populations or meaningful differences among species.

the rapid extinction of a large number of diverse species around the world caused by catastrophic events

Mass Extinctions

A Clade

Monophyletic groups

Before the application of DNA sequencing to fossils, which species concept was most useful for distinguishing human fossils?

Morphological species concept

a species as a population or group of populations that have measurably different anatomical features from other groups(beak size)

Morphospecies Concept

Paleontologists studying fossils of therapsids (a group of extinct mammalian ancestors) would likely use which of the following species concepts?

Morphospecies concept

Why are the large finches now living on the Galápagos Islands different from the original source population from a nearby island?

Natural selection favored individuals that were more fit in the new environment,The separation of habitats reduced gene flow between the populations, and Genetic drift occurred in the two populations

forms a new species can form via hybridization

New species

The Cambrian Explosion refers to the rapid evolution of major animal body plans. Does this mean that animals quit evolving after this time?

No-animals continued to evolve during and after the adaptive radiation.

The opposite of a clade

Non-monophyletic groups

identifies species based on the evolutionary history of populations.a species as the smallest monophyletic group in a phylogenetic tree.

Phylogenetic Species Concept

Which is the first step in allopatric speciation?

Physical isolation of two populations

How can allopolyploid individuals result in new species?

Polyploid individuals can only reproduce with other polyploid individuals but cannot interbreed with either parent species.

Condition of possessing more than two complete sets of chromosomes

Polyploidy

Most causes of speciation are relatively slow, in that they may take many generations to see changes, with the exception of _____.

Polyploidy

Which of the following statements about reinforcement is true? Reinforcement is a type of natural selection. Reinforcement increases the number of intermediate phenotypes. Reinforcement decreases the morphological difference between two incipient species. Reinforcement is also called dispersive selection.

Reinforcement is a type of natural selection.

What is reinforcement?

Reinforcement is due to natural selection against interbreeding and production of hybrid offspring

traits prevent interbreeding

Reinforcement of divergence

may occur, creating the appearance that no change occurred

Reversal of character trait

Which of the following groups could be identified using the biological species concept? Sunflower species living today Lizard species living today Bacteria living today Extinct dinosaurs

Sunflower species living today Lizard species living today

Speciation that occurs among populations within the same geographical area Often via Disruptive selection Can be initiated by two events extrinsic or intrinsic events

Sympatric speciation

Human impacts: Habitat loss Pollution Overfishing Invasive species Climate change

The 6th Mass Extinction

End Cretaceous extinction Late Triassic extinction End-Permian extinction Late Devonian extinction End-Ordovician extinction

The Big 5 mass extinction

Which of the following is considered a disadvantage of the phylogenetic species concept? The phylogenetic species concept utilizes many characteristics to establish relatedness between different species. The phylogenetic species concept characterizes species based on ancestry, and only monophyletic groups are recognized. The phylogenetic species concept can be used for any organism, including those that reproduce asexually. The phylogenetic species concept produces many more species than other species concepts, some of which are not easily distinguishable based on morphology.

The phylogenetic species concept produces many more species than other species concepts, some of which are not easily distinguishable based on morphology.

A subset of a population of birds leaves its habitat on the mainland and colonizes a nearby island. The birds, after a period of time, become reproductively isolated. The island sinks and the population of birds that lived on the island returns to its original habitat. Which of the following statements about these bird populations is true? The populations will not be able to interbreed because they are different species. The populations were sympatric while they diverged. The populations will be able to interbreed even though they are different species. The birds were separated by a vicariance event.

The populations will not be able to interbreed because they are different species.

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

To serve as an outgroup

Which of the following is an example of prezygotic reproductive isolation? Members of two species mate when kept together in captivity. Two frog species meet and mate with each other, but the hybrid offspring are infertile. Two bird species live in the same area and, though similar in plumage, engage in dramatically different courtship dances. Two beetle morphologies can be distinguished, but they are capable of interbreeding in areas where both morphologies are found.

Two bird species live in the same area and, though similar in plumage, engage in dramatically different courtship dances.

Which of the following is an example of prezygotic reproductive isolation? Two bird species live in the same area, and though similar in plumage, engage in dramatically different courtship dances. Members of two species mate when kept together in captivity Two beetle morphologies can be distinguished, but they are capable of interbreeding in areas where both morphologies are found Two frog species meet and mate with each other, but the hybrid offspring are inferitle

Two bird species live in the same area, and though similar in plumage, engage in dramatically different courtship dances.

Trumpeter speciation occured through the process of

Vicariance

What event triggered diversification of trumpeters in the Amazon rain forest? Interbreeding among related groups of trumpeters Dispersal into the Amazon basin Vicariance due to formation of the Amazon River system Colonization of South America by trumpeter ancestors

Vicariance due to formation of the Amazon River system

Prezygotic Barriers

a mechanism that prevents fertilization from occurring

Postzygotic Barriers

a mechanism that reduces the viability or reproductive capacity of hybrid offspring.

A monophyletic taxon would be best described as a grouping of _____.

all species descended from a common ancestor, including that ancestor

Why was mitochondrial DNA so useful in the study of the hybrid zone between Townsend's warbler and hermit warblers?

mDNA is maternally inherited, so the researchers were able to determine that most hybrids resulted from Townsend's males with hermit females.