1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Andrej [43]
3 years ago
11

PLEASE PLEASE HELP ME!!!! (10 POINTS!)

Biology
1 answer:
Oksi-84 [34.3K]3 years ago
7 0

Answer:

 

en Espanol en Español     print print

Bottlenecks and founder effects

Genetic drift can cause big losses of genetic variation for small populations.

Population bottlenecks occur when a population's size is reduced for at least one generation. Because genetic drift acts more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a population's genetic variation by a lot, even if the bottleneck doesn't last for very many generations. This is illustrated by the bags of marbles shown below, where, in generation 2, an unusually small draw creates a bottleneck.

Loss of genetic variation as a result of a population bottleneck

Download this graphic from the Image library.

Reduced genetic variation means that the population may not be able to adapt to new selection pressures, such as climatic change or a shift in available resources, because the genetic variation that selection would act on may have already drifted out of the population.

Elephant seal

 

An example of a bottleneck

Northern elephant seals have reduced genetic variation probably because of a population bottleneck humans inflicted on them in the 1890s. Hunting reduced their population size to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000 — but their genes still carry the marks of this bottleneck: they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted.

Founder effects

A founder effect occurs when a new colony is started by a few members of the original population. This small population size means that the colony may have:

reduced genetic variation from the original population.

a non-random sample of the genes in the original population.

For example, the Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of the gene that causes Huntington's disease, because those original Dutch colonists just happened to carry that gene with unusually high frequency. This effect is easy to recognize in genetic diseases, but of course, the frequencies of all sorts of genes are affected by founder events.

Explanation:

You might be interested in
is the genetic material that makes up living things, and folic acid plays an important role in the formation of DNA. Jon wants t
nadya68 [22]

Answer:

is the genetic material that makes up living things, and folic acid plays an important role in the formation of DNA. Jon wants to study the effect of folic acid on DNA formation in microbes. Which statement accurately describe the variables in this study?

Folic acid is the variable as it determines how DNA is formed, DNA contains the genetic materials that is passed across to offspring

Explanation:

6 0
2 years ago
Some snakes produce a powerful poison that paralyzes their prey. This poison is an example of
Evgesh-ka [11]

Answer:

This poisonis an example of an aboitic factor

4 0
3 years ago
Read 2 more answers
Which statement is a testable hypothesis? The dog salivating is an example of responding to stimuli. If the dog is given food, t
Leno4ka [110]

Explanation:

The dog salivating is an example of responding to stimuli

7 0
3 years ago
Who do yall think has it worst Boys or Girls
ivolga24 [154]

Answer:

i don’t really know

Explanation:

6 0
2 years ago
The primary role of the Nervous System.
kykrilka [37]

The nervous system has three main functions: To collect sensory input from the body and external environment. To process and interpret the sensory input. To respond appropriately to the sensory input.

8 0
3 years ago
Other questions:
  • What are the headings of a data table
    6·1 answer
  • Select the choice that best completes the following sentence: A normal human body cell has a total of ___ chromosomes: ___ chrom
    8·2 answers
  • during the race the body temperature of a runner increases. The runner body responds by perspiring (sweating), which lowers the
    6·2 answers
  • Place the parts of the circulatory system in the correct order
    8·1 answer
  • "Generally describe the series of events via which pyruvate is further processed after glycolysis (assume that this is in the pr
    8·1 answer
  • A convergent signal comes from many places to one place true or false?
    6·1 answer
  • Life functions are performed at many levels of biological organization. Which level of biological organization is the simplest l
    6·1 answer
  • Functions of the roots include,___
    10·2 answers
  • A pure substance that consists entirely of<br> one type of atom.
    14·1 answer
  • Scenario: Justin lives in Evanston, Illinois, U.S.A. The table above shows the times of sunrise and sunset at his hometown for t
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!