You are studying three populations of an endangered species of toad that used to be common in the California central valley. Global warming has caused this species to retreat to higher elevations in recent decades where it stays cooler; the toad used to be found throughout the valley, but is now restricted to the tops of three mountains. Historical records indicate that there used to be hundreds of thousands of toads in the central valley, but sampling the mountaintops reveals that the toad population on each is now limited to a few hundred individuals. You survey allozyme diversity at one locus on each of the three mountaintops and find that each population is fixed for a different allele of the ribbit gene: mountain #1 is fixed for the A1 allele, mountain #2 for the A2 allele, and mountain #3 for the A3 allele. The average number of baby toads born in each population is the same, and the environment on each mountaintop is very similar, as far as your data show.
Explain why each population is fixed for a different allele.
Sentence 1: Describe the variability that was initially present in each of the populations.Sentence 2: State which individuals had the highest fitness in a given population, or why fitness is not an issue if that is your conclusion.Sentence 3: Explain what evolutionary force acted on the population(s), and why and how it acted.Sentence 4: Describe how the populations evolved in response to their changing environment. Be as specific as you can (e.g., say "increased" or "decreased", rather than just "changed".)

Answers

Answer 1

Answer:

Explanation:

The allele are fixed because there is no variation that exist in the population and the allele are almost completely the same hence no new combination of gene the same Allele will continue to reoccur

Variability exist because of random mating that occurs in the population initially when the toad filled up the entire central valley

Random mating ensures fitness in the initial population

Genetic drift acted upon the population drifting away allele that are very few in population or that occur less in the population and perpetuating alleles that frequently occur leading to a fixed allele.

There was a decrease in the population as a result of the change in the environment.


Related Questions

role of the two components of the ribosomal complex.​

Answers

Answer:

The ribosome is a highly complex cellular machine. It is largely made up of specialized RNA known as ribosomal RNA (rRNA) as well as dozens of distinct proteins (the exact number varies slightly between species). The ribosomal proteins and rRNAs are arranged into two distinct ribosomal pieces of different size, known generally as the large and small subunit of the ribosome.

Explanation:

Choose the word or phrase that best completes each sentence about the worldwide domestication of plants and
animals.
Different plants were domesticated to grow crops
A major cause of the agricultural revolution was the
A major effect of the agricultural revolution was

Answers

Answer:

1. in many parts of the world (c)

2. warming of the earth after the ice age (c?)

3. The creation of a food surplus ( B)

Explanation:

I did it and got it right

Answer:hopefully that helped..

Explanation:

Which of the following units are repeatedly joined together to form a strand of DNA?​

Answers

Answer:

Nucleotides

Explanation:

The nucleotides forming each DNA strand are connected by noncovalent bonds called hydrogen bonds.

Nucleotide is the unit that repeatedly joined together to form a strand of DNA.

What is DNA?

Deoxyribose + phosphate group + thymine could be a nucleotide of DNA and defined as deoxyribonuclic acid and it is a polymer made up of two polynucleotide chains that arranged in foiled structure to form a double helix carrying genetic information for the various processes such as growth development  functioning and reproduction.

There are four nitrogen bases of DNA nucleotides are such as adinine, thymine, guanine and cytosine.

Friedrich miescher discovered DNA in the year of 1860.The shape of DNA is double helical structure

The main function of DNA is to carry information from one generation to another generation this is the reason due to which DNA is also known information molecule.

In our body DNA is found in the nucleus of the cell and it is known as nuclear DNA. The shape of DNA is double helical structure.

Siblings share only about 50% of same DNA due to the reason of recombination. The life span of DNA is 521 years.

Therefore, Nucleotide is the unit that repeatedly joined together to form a strand of DNA.

Learn more about DNA here:

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what structure help to keep the stem's shape and up right position?​

Answers

Answer:  

The cell wall.

Explanation:

Which of these molecules structures could be found in a lipid, but not in a carbon hydrate, protein, or nucleus acid?

Answers

In the down you have the answer, I hope it helps you...

Answer:

B: a long chain made only of carbon and hydrogen atoms

Explanation:

What is the concentration of a solution

Answers

Concentration = mass (or moles)/ volume. Let me know if you have a specific question in mind

The _____ photosynthesis reactions convert light energy into chemical energy, which is stored in molecules like ATP. In the ____ photosynthesis reactions, this energy is used to convert CO^2 into carbon sugars.

Answers

Answer: A

Explanation:

Which statement is true about the appendicular skeleton of the human body?

Answers

Answer:

I am pretty sure it is, The consists of the bones that form the limbs and the bones that attach the limbs to the axial skeleton. But I am not positive, I hope this helps!!

Explanation:

Option C, It consists of the bones that form the limbs and the bones that attach the limbs to the axial skeleton.

The part of the vertebrate skeleton that has the bones that hold up the body is the appendicular skeleton, which comprises the elements within the limbs, pelvic and pectoral girdle. It holds the bones that produce and uphold the libms and joins them with the axial skeleton. The appendicular skeleton has 126 bones and helps manipulate the upper limbs.

Which are the main points of the cell theory? Select all that apply.

Answers

Answer Options:

a. Cells are the basic units of structure and function in living things.

b. New cells are produced from existing cells.

c. All cells enclose their DNA within a nucleus.

d. All living things are made up of cells.

Answer:

a. Cells are the basic units of structure and function in living things.

b. New cells are produced from existing cells.

d. All living things are made up of cells.

Explanation:

Cell theory states that cell living organisms are composed of at least one cell, which are the basic unit of life.

Cells are always produced from other living cells, and cannot spontaneously generate.

However, not all cells enclose their DNA within a nucleus, prokaryotic organisms (bacteria) do not possess a nucleus but still have DNA

Which sentence from the passage best expresses the main idea of paragraph 2?
A.
"Parkour has become a popular art form in many cities around the world due to the many obstacles located around urban settings."
B.
"Traceurs, who pit their bodies against various types of obstacles, often risk physical injury, and safety is an important concern."
C.
"The ultimate goal of parkour is for a person to mentally and physically prepare to overcome any obstacle he or she may face."
D.
"While practicing parkour, a traceur route may take him or her over a large boulder, across several rooftops, or across the top of a wall."

Study island work Plz help

Answers

Answer:

You cant wander this because you dont know the paragraph

Explanation:

theres no paragraph for us to see

Answer:

B. "Traceurs, who pit their bodies against various types of obstacles, often risk physical injury, and safety is an important concern."

Whats an explanation for the cycling of matter and flow of energy in
anaerobic conditions>

Answers

Answer:

Energy drives the cycling of matter within and between systems in aerobic and anaerobic conditions.

Explanation:

The process of removing wastes from the cell is known as

A.) endocytosis
B.)exocytosis
C.) pump
D.)channel

Answers

The answer B I hope this help you

Help me answer this please ASAP

Answers

hm not really sure but I’ll go with c

You have two substances. Alcohol: density 0.8 g/ml and Glycerin: density
1.4 g/ml.Which substance will float in water?*
1 point

Answers

Answer:

The alcohol will float

Explanation:

Alcohol is less dense than water, compared to Glycerin which is more dense than water, (Water's density is 1.0)

As a college student, you are no doubt concerned about the grades that you earn while completing your coursework. If you wanted to know how overall GPA is related to success in life after college, how would you choose to approach this question and what kind of resources would you need to conduct this research?

Answers

I am not a college student, I am a Freshman in High School but if I were in college this is what I would say:

In college the GPA of the student is very important and it helps a student obtain good colleges and courses in this regard.

The data collected from college alumni about their careers after college would be the required resource in this case.

What is meant by a research resource?

The kind of research one wants to do and the kind of questions in mind guide the kind of resources required for research. Currently, access to any kind of information for anyone is greater than ever before.

Thus, for good research, it's important to collect data from the right kind of resources. It needs to be located, organized, evaluated, and used for the communication of information.

Various places can be a home for a research resource or be research resources themselves. These can be traditional libraries. Whereas, personal experiences can be important research resources.

Print media, which includes journals, books, brochures, newspapers, and magazines are conventional research resources. Currently, electronic sources found on the Internet are being used. Interviews or surveys can also be considered research resources.

Therefore, to understand the impact of GPA on students' careers, we need to collect data on their careers.

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If two heterozyotes for dwarfism have children what proportion of their kids would you expect to be of typical size and not exhibit dwarfism?

Answers

Answer:

3/4 or 75%

Explanation:

This question involves a gene coding for height in humans. The allele for normal height (D) is dominant to the allele for dwarfism (d).

If two heterozygotes for dwarfism are crossed i.e. Dd × Dd, the following gamete will be produced by each heterozygote parent:

Dd - D and d

Using these gametes in a punnet square (see attached image), the genotypes of the expected offsprings will be as follows- DD (1) : Dd (2) : dd (1)

(1) DD - typical normal size

(2) Dd - heterozygous normal size

(1) dd - dwarf

The offsprings expected to be of typical size and not exhibit dwarfism are offsprings DD and Dd, which represent 3/4 of the offsprings. Hence, the proportion is 3/4 or 3/4 × 100 = 75%.

What is the Connective tissue?

What is the Epithelial tissue?


What is the Muscle tissue?


What is the Nervous tissue?​

Answers

Answer:

connective: Tissue that supports, protects, and gives structure to other tissues and organs in the body

epithelial: are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands.

muscle: Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts. The tissue is highly cellular and is well supplied with blood vessels.

nervous: Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities.

Explanation:

Answer

Connective tissues gives support, protects and gives structure to other tissues and organs in the body.... example bone, cartilage, blood etc.

Epithelial tissues are spread throughout the body. Their functions include secretion (sweat, mucus), absorption (nutrients) and protection (tissues that lie beneath from radiation) in the body.

Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts.

Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities.

Prevailing winds blow from the Pacific Ocean toward two cities separated by mountains. City A is on the leeward side of
the mountains and city B is on the windward side. Which city is likely to have a wetter climate? Explain your answer.

Answers

Answer:

City B will have a wetter climate.

Explanation:

This is because in windier areas in tends to get more wet than rocky areas (mountains) where City A lies. Also because more wind will blow more and more clouds in the direction of city B making it rainier there a lot more often than a non windy rocky are.

What are two ways different types of organisms obtain glucose?

Answers

Answer:

Photosynthesis and respiration are two ways organisms obtain glucose.

Explanation:

Photosynthesis – process in which autotrophs use energy from the sun to produce their own food.

Respiration – process in which animals and plants use oxygen in the air to release energy found in glucose.

Hope this helps!

Francine is developing a model of the carbon cycle, which involves the movement of carbon among various Earth systems. She begins by drawing the diagram shown below. Her friend Byron evaluates the model, and suggests that she thicken the arrow leading from fossil fuels to the atmosphere. His reasoning is that fossil fuels are being burned at a much faster rate than natural processes are restoring them. If Francine adopts Byron’s suggestion, how could her model be used to explain a significant change to Earth's systems?

Answers

Answer:

After adopting the suggestions of Byron the new or revised model would show that using fossil fuels at a rapid rate would lead to higher inputs of carbon dioxide to the atmosphere which will not be removed by the natural process of removing the excess amount of the carbon dioxide by the process of the photosynthesis and other.

The carbon dioxide would increase due to this and cause trapping of the solar heat in the atmosphere which leads to the greenhouse effect to warm the earth. That ultimately changes the climate of the earth.

In soreflies (a hypothetical insect), the dominant allele, L, is responsible for resistance to a common insecticide called Loritol. Another dominant allele, M, is responsible for the ability of soreflies to sing like birds. A true-breeding mute, Loritol-resistant sorefly was mated to a true-breeding singing, Loritolsensitive sorefly, and the singing, Loritol-resistant female progeny were testcrossed with true-breeding wild-type (i.e., mute, Loritol-sensitive) males. Of the 400 total progeny produced, 119 were mute and Loritol-resistant, 114 could sing and were Loritol-sensitive, 81 could sing and were Loritol-resistant, and 86 were mute and Loritol-sensitive. Do you think the (L) and (M) gene loci are linked or unlinked? Justify your answer

Answers

Answer

The (L) and (M) gene loci are linked.

Explanation:

Due to some technical problems, you will find the complete explanation in the attached file named Linked genes.

how does bacteria from the fecal transplant fill up the space in the gut, limiting the food and space for invading harmful bacteria?

-To help you write, review your work from this lesson, including the Reasoning Tool.

-To help you organize your thinking and construct your ideas, refer to the Scientific Argumentation Sentence Starters.

-The Microbiome Research Institute will publish this press release as as way to inform the public and defend their funding. (not really. my teacher added this.)

Answers

Answer:

unsure of your answers but I got this, By reintroducing a healthy diversity of bacteria, fecal transplantation can re-establish .

Female killer whales can live for ____ years or more. 50 80 30 60
PLEASE HELP

Answers

Answer:

50 years

Explanation:

name of any intrusive igneous body.

Answers

Answer:

Hello!!! Princess Sakura here ^^

Explanation:

One is batholith.

Spartina is a group of grasses that dominates communities of salt marshes in many coastal areas. Many of the insects, snails, birds, mice, and other animals found in these communities rely on Spartina for food, nest building materials, protection for their young, etc. The roots of Spartina also form dense mats that hold together soil in these ecosystems. Many species that live in Spartina salt marshes cannot survive outside of these unique ecosystems. Because living near the ocean is desirable to many humans, many Spartina marshes have been drained & cleared for human development. Analysis of the destruction that came when Hurricane Katrina hit Louisiana in 2005, however, showed that the reduction of salt marshes in coastal Louisiana was a contributing factor to the storm surge penetrating further inland.
1. The value of Spartina salt marshes in protecting coastal areas from storm surge would be classified as which type?
A. Extrinsic.
B. Intrinsic.
C. Neither.
2. The value of Spartina salt marshes in holding soil together would be classified as which type?
A. Extrinsic.
B. Intrinsic.
C. Neither.
3. In general, you would expect species that only live in Spartina salt marshes to have a higher extinction risk than species that can survive in urban areas.
A. True
B. False
4. Based only on the information included in this scenario, extinction risk for species that only live in Spartina salt marshes would be most influenced by which factor?
A. Restricted geographic range.
B. Narrow habitat requirements.
C. Small population size.

Answers

Answer:

1)a. Extrinsic

2) b. Intrinsic

3) a. True

4) a. Restricted geographic range

Explanation:

1. Spartina Salt marshes are important to the coastal areas as they protect them from storm surge as affecting the erosion of salt marsh edges and it is classified as extrinsic.

2) b. Intrinsic

Intrinsic factors such as vegetation and soil affect the erosion of salt marsh edges.   It is determined by characteristics of soil and root biomass found under the ground.

3) a. True

Species that could survive in urban areas are less prone to extinction than the species that only survive in spartina salt marshes.

4) a. Restricted geographic range

A restricted geographic range is a factor that leads and affects the extinction in endemic species more.

What is the purpose of transciption?
A RNA -----> Protein
B RNA ---> DNA
C DNA ------> Protein
D DNA ----> RNA

Answers

Answer:

DNA into RNA

Explanation:

Based on their scientific name, you know that African bush elephants, or Loxodonta africana, and African forest elephants, or Loxodonta cyclotis, belong to the same

Answers

Answer:

they belong to the same Species

Explanation:

Loxodonta must mean "Elephant" because both scientific names are the scientific versions of elephants. This must mean that the answer is that they belong to the same species.

Answer:

To the same species

Explanation:

it just is

Students will analyze information about how the reduction in numbers of an individual species can affect an entire ecosystem

Answers

If one population dies out, all the populations that depend on that species for food may also die out. A change in one population affects the entire community because all the populations of a community depend on each other.

PLEASE HELP MEEEEE QUICKLYYYY


a group of students found the specific gravity of a pice of galena to be 7.8. The accepted value for the specific gravity of galena is 7.2 find the % of error in the student's work

Answers

Answer:

Percent error = 8.3%

Explanation:

Given data:

Accepted value of specific gravity = 7.2

Measured value of specific gravity =  7.8

Percent error = ?

Solution:

Percent error = measured value - accepted value / accepted value × 100

Now we will put the values in formula.

Percent error = 7.8 - 7.2/7.2 × 100

Percent error = 0.6/7.2 × 100

Percent error = 0.083 × 100

Percent error = 8.3%

What is the difference between an independent variable and a dependent variable? How are these different from constants?

Answers

The variables in a study of a cause-and-effect relationship are called the independent and dependent variables. The independent variable is the cause. Its value is independent of other variables in your study. The dependent variable is the effect.
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