evolution and speciation

adaptive radiation

Galápagos finches supposedly underwent a(n) ______ after an ancestral population arrived on the islands about 2 million years ago and eventually evolved into a cluster of 14 species with different feeding adaptations.

it restricts gene flow

Geographic isolation can accelerate speciation because _____.

relative dating

Geologists of the nineteenth century were able to use ______ to get a fairly accurate idea of the age of rocks using their positions in the strata and known rates of erosion.

Although fertilization is successful, the resulting hybrid is unable to reproduce.

How do postzygotic isolating mechanisms prevent successful interspecies hybridization?

The parent species do not come into contact with one another

How does ecological isolation prevent successful interspecies hybridization?

a species concept

If organisms are distinct in one location, and populations of those organisms are reproductively connected by the breeding of individuals, we have the necessary components for ____.

the evolution of reproductive isolating mechanisms

If reproductive isolation is the criterion used to define species, then the process of speciation is equivalent to ____.

post zygotic

In ______ isolating mechanisms a hybrid zygote is formed, but it is unable to survive or reproduce due to developmental or genetic problems.

artificial natural

In ______ selection, humans choose the parents of the next generation, while in ______ selection, organisms that survive and reproduce are those that pass their genes on.

decreased

In the early 1850s, scientists noticed that the frequency of light colored peppered moths in polluted areas ____.

natural selection

Most scientists agree that the primary process responsible for evolution is

embryological development

One of the strongest lines of anatomical evidence of evolution is exhibited by patterns of ______ that are common to a group of related organisms

light black

Peppered moths come in a variety of shades, from _______ gray with speckles to completely________ (melanic).

very rare

Prior to 1850, the melanic form of the peppered moth in Europe was ____.

isolation

Reproductive ____is the key to the process of speciation.

Natural selection

Review the following list of processes that can alter the genetic make up of a population. Which one is considered by scientists to be primarily responsible for evolution?

Color vision genes are similar among relatives of humans. All animals possess similar pattern formation genes.

Select all of the following that provide molecular evidence of evolution.

The variation must lead to differences among individuals that affect reproductive success. The variation must be genetically transmissible. There must be variation in the population for the trait being examined.

Select the conditions that scientists must demonstrate are occurring in studies of natural selection in action.

vestigial structures.

Some species have anatomical features that have no apparent function but resemble structures of their presumed ancestors; these anatomical features are called

gene flow

Speciation is more likely in geographically isolated populations because which of the following does not occur?

sympatric

Species that are _____ species can occur in the same location and are phenotypically different.

increased; almost 100%

Starting in 1850 when Europe become industrialized, the frequency of melanic forms of the peppered moth in populations ______ until they made up ______ of some population.

homologous

Structures with different appearances and functions that are all derived from the same body part in a common ancestor are called ______ structures.

False reason: there are many types of organisms that have been modified by artificial selection, including many plants such as corn, strawberries, etc.

True or false: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts.

False

True or false: Organisms that are more closely related have accumulated a greater number of genetic changes.

Adaptive radiation

What evolutionary process leads to the existence of groups of closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment?

Polyploidy

What mechanism can cause immediate reproductive isolation and lead to sympatric speciation?

Direct

What type of evidence for evolution is provided by fossils?

Formation of islands through volcanic activity and subsequent colonization A species occurs in an environment with few other species and many resources

What types of conditions may lead to adaptive radiation?

species

When members of two populations are completely reproductively isolated, they will remain two distinct ______ when they come into physical contact.

convergent evolution

When two species from different lineages independently evolve similar characteristics because they occupy similar environments, we observe ______.

Hybridization in natural settings

Which is left unexplained by the biological species concept, thereby weakening the concept?

Distinctiveness of species that occur together in a single location Connections between different populations of the same species

Which must be accounted for in any species concept?

Rocks are dated by their relative position, rocks in deeper strata being generally older.

Which of the following describes the process of relative dating used to estimate the age of rocks and fossils in the nineteenth century?

Fossils

Which of the following is the most direct evidence for evolution?

Conserved DNA sequences

Which of the following would be molecular evidence of evolution?

Polyploid individuals cannot mate with normal diploid individuals.

Why does polyploidy lead to sympatric speciation?

Convergent

______evolution happens when natural selection appears to have favored parallel adaptations in unrelated organisms that live in similar environments.

sympatric species.

species that occur in the same geographic area but are distinct species because they look different, utilize different parts of the environment, or behave differently, are

vestigial

A _____ structure has no apparent function in a species, but is fully functional in the species' ancestors.

character displacement.

A process that can drive adaptation to minimize competition for resources among sympatric species is called

the more different they are molecularly.

Because changes in traits are due to changes in alleles of a gene, the more distantly related two organisms are,

the geographic distribution of modern and extinct species.

Biogeography is the study of

1. greatest similarity is present 2. different characteristic are lost or formed 3. final form is obtained

Developmental patterns seen in a group of organisms often reveal evolutionary relationships. Place the developmental descriptions in the order that they would occur in a group of related organisms, beginning with the earliest description at the top.

Modern horses have a single toe enclosed in a bony hoof

Early horses had four toes on the front feet and three toes on the hind feet, all encased in fleshy pads. What statement correctly describes how the toes have changed during the evolution of modern horses?

corn. cattle. pigs.

Economically important organisms that have been modified significantly through artificial selection include

is heritable.

Evolution by natural selection requires that variation exists for a trait, the variation in the trait leads to differential reproductive success, and that the variation

homologous structures.

Evolutionary biologists believe that even though they serve different functions, the forelimb of a frog and the forelimb of a bat share structural similarities and are derived from a common ancestor. This makes these forelimbs an example of

Differences in their feeding habits

Finches on the Galapagos islands exhibit remarkable variation in the shape of their beaks. What best explains this variation?

1 4 3

The feet of modern horses have____toe(s); in contrast, early horses had _____ toe(s) on their front feet and ______ toe(s) on their hind feet.

adaptive radiation

The formation of small islands by volcanic activity and subsequent colonization may all lead to______ ______ , evolution of a closely related group of species adapted to different parts of the environment.

cichlid

The great diversity observed in the ______ fishes in Lake Victoria is an example of adaptive radiation.

melanic

The jet black form of the peppered moth (Biston betularia) is also know as the_____ form.

Hybridization

The not uncommon occurrence in natural settings of which of the following weakens the biological species concept?

adaptive radiation.

The phenomenon in which a cluster of species evolves to occupy several different niches within a region is called

how the parents are chosen (by humans or because of their reproductive success)

The primary difference between natural and artificial selection is

ecological isolation

The reproductive isolating mechanism that occurs when the ranges of two species overlap, but they rarely come into contact with one another because they utilize different habitats is