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

Large selection coefficients keepin' us all together

Gene ExpressionBy Razib KhanMarch 15, 2006 11:37 PM

Newsletter

Sign up for our email newsletter for the latest science news

In my post below there is a reference to fast evolution in a relatively slow-breeding species, H. sapiens. For this to be plausible you need high selection coefficients, that is, the difference between mean population fitness and the fitness of those who are carrying the favorable allele. How plausible is this? R.A. Fisher argued against selection coefficients of large effect because he believed that mutations of large effect would usually "overshoot" the idealized fitness peak, and it was mutations of small gradual effect which were the real drivers of evolution. But recent work has reemphsized the possible importance of fast sweeping positively selected mutations across populations. And with that, I point you to How species evolve collectively: implications of gene flow and selection for the spread of advantageous alleles. Relevant sections:

Crude estimates on the strength of selection on phenotypic traits and effect sizes of quantitative trait loci (QTL) suggest that selection coefficients for leading QTL underlying phenotypic traits may be high enough to permit their rapid spread across populations. Thus, species may evolve collectively at major loci through the spread of favourable alleles, while simultaneously differentiating at other loci due to drift and local selection.

The full text is available for those without academic access at the link provided.

    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