Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Health

The baby model

Gene ExpressionBy Razib KhanSeptember 19, 2006 10:58 PM
mutandall.jpg

Newsletter

Sign up for our email newsletter for the latest science news

A few weeks ago I posted my fixations which put the spotlight on some elementary population genetics formalisms. I thought I'd put my elementary Illustrator skills to use and throw up the canonical diagram use to elucidate basic population genetics in many classrooms. Here you see two demes, two breeding populations, and the arrows show the factors which increase and decrease genetic diversity. While mutation increases genetic variation, genetic drift tends to remove variants. Similarly, while balancing selection, whether it be frequency dependent or heterozygote advantage, tends to perpetuate variation, positive or negative selection either constrains or sweeps across populations to maintain or generate homogeneity. Add to this the added parameter of deme-to-deme gene flow, and you have another parameter can speed up evolutionary processes, or, if you accept the Shifting Balance model, dampen it.

    2 Free Articles Left

    Want it all? Get unlimited access when you subscribe.

    Subscribe

    Already a subscriber? Register or Log In

    Want unlimited access?

    Subscribe today and save 70%

    Subscribe

    Already a subscriber? Register or Log In