ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Evolutionary Forces that Impact Variation Within Species

Updated on July 21, 2016

Variation Among Species

There are several different scientific processes that lead to differences or variation within the same species. This includes differences in traits like eye and hair color, height, and even tolerance to the sun. Both microevolutionary and non-evolutionary forces combined to affect allele frequencies which are responsible for different traits. Evolutionary mechanisms, include genetic drift, gene flow, mutations and natural selection. These evolutionary forces are the reason that people and other different species look so different from each other.

Gene Flow

  • An allele is a different variant of a gene. Offspring receive one allele from each of their parents for any given trait. This causes the different populations to become genetically similar.
  • Gene flow occurs when alleles are passed from one population to another. The variation within the recipient population will increase, but the variation between the two populations will decrease.
  • Geographical distance plays an important role in gene flow. Populations that are close together will be more similar genetically.
  • Culture also plays an important role in gene flow. If a community does not intermix with other populations because of religious or other cultural practices, gene flow does not take place.

Source

Mutations

  • Mutations are random changes in the DNA that can create new alleles which leads to new genetic variations. Mutations are extremely rare, and only mutations that occur in sex cells are passed on to offspring.
  • Mutations can be beneficial, harmful or neutral. When a mutation does occur in a sex cell, and a new allele is passed on to offspring, the fate of the allele is mostly left to genetic drift. Since it is rare, more than likely the new allele will be wiped out.

Natural Selection

  • New alleles created by mutations can also be spread through a population by natural selection. Natural selection is the phenomena that advantageous alleles are more likely to be passed on.
  • If a new allele gives an individual some type of reproductive advantage, that individual will be more likely to pass on their genetic material containing the allele than an individual without the allele.
  • Over time, the allele will become more common, and the overall allele frequencies will change. There is no guarantee that an advantageous allele will present itself in any given generation.

Genetic Drift

  • Random genetic drift occurs in every population because the passing of alleles from one generation to the next is essentially random. Each parent can only pass one allele to their offspring.
  • Since each reproduction is an independent event, each allele has an equal chance of being passed on every time the parent reproduces.
  • Genetic drift has a particularly important impact on small populations. In small populations, it is possible for some traits to be lost because no one in a generation inherits a particular gene.
  • Mixture of genetic material between populations, or gene flow, will usually counter the effects of genetic drift.
  • However, if there is not mixture between populations there is no other counter to the effects of genetic drift. If a gene is eliminated, the only way a new gene can be introduced into the population is a mutation.

The blue allele was not passed from parent to offspring.
The blue allele was not passed from parent to offspring.

Conclusion

The combination of these forces results in the tapestry of life we see all around us. It is the reason that humans come in so many shapes and sizes. It's the cause of different breeds of dogs. Ultimately these evolutionary forces have been the building blocks of life for millions of years, but their daily impact can be seen all around you every day.

Comments

    0 of 8192 characters used
    Post Comment

    • brenda12lynette profile imageAUTHOR

      brenda12lynette 

      6 years ago from Utah

      Thanks Vasiliki! I think learning all the intricate details about life makes it so much more fascinating!

    • Vasiliki Bouras profile image

      Vasiliki Bouras 

      6 years ago

      Excellent, and very informative.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)