New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Population Genetics

by: Crystal Florman

Population Genetics BIOL 1014

Crystal Florman
GPA 3.64

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

How genes are expressed and passed through a population
Life: Continuity and Change
Dr. Kurt Pontasch
Class Notes
population, Genetics, demes, genotype, phenotype
25 ?




Popular in Life: Continuity and Change

Popular in Biology

This 3 page Class Notes was uploaded by Crystal Florman on Saturday April 9, 2016. The Class Notes belongs to BIOL 1014 at University of Northern Iowa taught by Dr. Kurt Pontasch in Spring 2016. Since its upload, it has received 106 views. For similar materials see Life: Continuity and Change in Biology at University of Northern Iowa.

Similar to BIOL 1014 at UNI


Reviews for Population Genetics


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 04/09/16
Population Genetics  Introduction o Most organisms don’t exist as isolated individuals instead they form a population o Population- organisms of a given species found within the same geographic region o Species- group of organisms that have the ability to breed and produce fertile offspring- same number and kinds of chromosomes o Population Genetics- the study of why differences in gene frequencies occur in a population  Ex: frequency of gene type, skin color, hair color, etc.- varies among human populations- can be more than 2 alleles for a characteristics among a population  Gene Pool o Consists of all the genes of all the organisms that are in the population o Each individual’s genotype is a subset of that gene pool o As a result of several factors such as: geographic barriers or resource availability the individuals within the population are found in clusters  These clusters breed with each other more often than with individuals outside the cluster o Because of this breeding within clusters- clusters of genes called demes will occur within the local population  If there is little exchange of genes between demes the demes will differ phenotypically  Subspecies- still the same species- called breeds in domestic animals  Gene Frequency o Usually stated mathematically in terms how often a particular gene turns up in the gametes of a particular population o Possible for 2 demes to have the same gene pool but different gene frequencies  Ex: all humans constitute one large gene pool, but different ethnic groups have different gene frequencies o Once gene frequencies are established within a deme- the frequencies don’t change much unless there is a reason o Gene Frequencies have nothing to do with dominant and recessive genes  Recessive genes are often more frequent then dominant within a given deme o What determines the frequency of genes within demes and population is the value of the gene in helping the organism survive and produce offspring******  Why Demes Exist o Although no to individuals in a deme are exactly alike the members of a deme resemble each other more closely than they do members of other demes- why?   More closely related genetically because they breed with each other more often than members of other demes  Exposed to the more similar environmental influences- selection pressures o Demes are not clear cut units of population o Demes exist because of  Geographic barriers  Environmental differenced  Ex: temperatures change with altitude and latitude o New demes form when organisms emigrate and form a new population o A population in which there is little genetic variability often displays a high frequency of undesirable characteristics  Ex: hemophilia in the royal family in Europe  In addition such a small gene pool can result in a lower adaptability to environment changes- may lead to extinction  On the other hand- a large gene pool is more likely to contain genes that will help some of the organisms to survive environmental changes  How variability is Generated o 4 main mechanisms that introduce variability into a gene pool  Mutations  All alleles have originated as a result of mutations  Mutations that code for bad characteristics result in alleles that are uncommon in the population- less fit- most mutations are bad  Mutations that code for good characteristics result in alleles that become more common in the population- changes gene frequency  Sexual Reproduction  Tends to result in new genotypes but not additions to the gene pool of population o However when a new genotype is produced that is superior to others in the gene pool it will be more successful in producing offspring- change gene frequency  Migration  When an individual migrates from one deme to another- genes can be added to the new population and subtracted from the old- changes in the gene pool  Size of Population  The smaller the population the less variability it can contain  Determines the effectiveness of the things above ingenerating variety in the gene pool  Domesticated Plants and Animals o Humans often work with plants and animals to artificially construct gene combinations that are desirable o Many plants and now animals can be reproduced asexually to form individuals with exactly the same genotype- clones o We can also bring together desired characteristics in plants and animals by selective breeding o Selective breeding is usually accomplished by:  Finding wild demes that are homozygous for the desired trait  Breed small groups that are homozygous dominant for desired traits o By breeding 2 organisms that are homozygous for different desired traits we can produce offspring with both traits  These offspring are heterozygous for those traits- Hybrids  Hybrids wont breed true for these desired traits among themselves- must be managed to prevent the formation of unacceptable gene combinations o When we use selective breeding to increase the frequency of desirable traits other genes are lost from the gene pool  Today most of our crops are planted as vast fields of similar genotypes- monoculture o Small gene pool within a monoculture can result in:  The need for herbicides and insecticides to maintain the proper conditions for plant growth  Greater potential for a new disease or a change in environmental conditions to wipe out entire population


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Anthony Lee UC Santa Barbara

"I bought an awesome study guide, which helped me get an A in my Math 34B class this quarter!"

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.