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So why do equal probabilities of survival and reproduction reproduce parental allele frequencies in the offspring generation?

Hopefully the answer to this question is more obvious now that you understand that an equal likelihood of surviving and producing surviving offspring is really about each individual having an equal chance of providing one of the two gametes to every fertilization event that occurs in a population and produces a surviving offspring. Nothing is operating to bias the chances of an individual contributing a gamete to each and every fertilization event and every individual's two alleles have an equal (50:50) chance of ending up in the gamete involved in fertilization. But in case its not quite clear, let's explore the issue a bit further.

To do this, re-examine the pool of potential gametes depicted as buckets in the cartoon above (which is repeated below for your benefit) and answer the questions that follow.

Population of 10 individuals. Each individual's genotype appears in its 'head'. Each individual's buckets represent the two types of gametes the individual produces in equal numbers based on its genotype for a single locus.

a. If a gamete is randomly selected from this population, as happens when each individual has an equal chance of surviving and reproducing, what is the likelihood (probability) that it contains an A allele?

b. Explain the reasoning behind your response to question a.

Much as there is a 13 in 20 chance of blindly pulling a gold chip out of a bag of 20 chips of which 13 are gold and 7 blue (and they differ in no other way), there is a 13 in 20 or 65% chance that the gamete would contain an A allele, if a a gamete were randomly selected from the population above (13/20 = 65/100 = 0.65*100 = 65%). Buckets of A alleles are nearly twice as common as buckets of a alleles. Consequently when reproduction is random, as happens when every individual has an equal probability of surviving and reproducing, any randomly selected parent is nearly twice as likely to be carrying an A allele as opposed to an a allele.

Now consider the following questions.

a. If 15 random matings took place in this population, requiring a total of 30 gametes to be randomly selected, what is the likelihood that each randomly selected gamete contains an A allele? How about an a allele?

b. Explain the reasoning supporting your response to question a.

c. Imagine all 30 of the gametes resulting from 15 random matings displayed on a piece of paper in front of you, how frequently would you expect the A allele to occur in this collection? The a allele? Why? Please explain.

d. Review your responses to questions a and c. What do they tell you about how likely (frequently) the A allele is to appear in the offspring population? The a allele? Why? Please explain.

Ideally, your responses to questions a and c were identical. For each of the 15 random mating events, the probability that a contributed gamete contains an A allele is 13/20 (65%) and an a allele 7/20 (35%). This is true because each gamete selection event is independent; the allele one gamete contains does not in anyway influence what allele the second gamete of a fertilization event will contain if mating is random. (This is not true is mating is not random. Can you provide an example?)

Since the above is true for each individual mating event, the overall allelic composition of the resulting offspring generation will simply reflect the probability associated with picking each allele during each random gamete selection event summed for all 30 events. Therefore, on average 65% of the 30 alleles will be A and 35% a in the offspring generation if mating is truly random.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Understanding the hardy-weinberg equation. OpenStax CNX. Oct 22, 2007 Download for free at http://cnx.org/content/col10472/1.1
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