Cover Image: December 2003 Scientific American Magazine See Inside

Does Race Exist? Human Genetic Diversity [Preview]















Share on Tumblr

Click for full-size image" data-pin-do="buttonBookmark">

Click for full-size image Image: NADIA STRASSER

Researchers often use short pieces of DNA called Alu polymorphisms to determine whether various populations are related to one another. Alus have no known function, yet they copy and insert themselves at random throughout a person's genome. Because previously inserted Alus do not excise themselves, Alu patterns can be used as yardsticks to estimate how close two people--and, on average, two populations--are genetically. For example, an Alu polymorphism on chromosome 1 occurs in roughly 95 percent of sub-Saharan Africans who have been sampled, 75 percent of Europeans and northern Africans, and 60 percent of Asians, whereas a different Alu polymorphism on chromosome 7 is carried by approximately 5 percent of sub-Saharan Africans, 50 percent of Europeans and northern Africans, and 50 percent of Asians. Some individuals carry both polymorphisms. No single polymorphism can, by itself, distinguish all the members of one major human group from all the members of another group, but by analyzing hundreds of these polymorphisms, scientists can group individuals sampled from different locations on the basis of their genetic profiles.



Subscribe     Buy This Issue

Already a Digital subscriber? Sign-in Now
If your institution has site license access, enter here.

1 Comments

Add Comment
View
  1. 1. boomslice 08:30 PM 7/14/08

    I'm doing a lab report on this topic and i can't find anything that explains exactly what an Alu sequence is. I'm only a junior taking summer bio, i just need a simple but consice definition. Nothing overly detailed or using any complex terminology. Thanks.

    Reply | Report Abuse | Link to this
Leave this field empty

Add a Comment

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

More from Scientific American

See what we're tweeting about

Scientific American Editors

Tweets could not be retrieved at this time

Free Newsletters


Get the best from Scientific American in your inbox

Solve Innovation Challenges

Powered By: Innocentive

  SA Digital
  SA Digital

Science Jobs of the Week

Email this Article

Does Race Exist? Human Genetic Diversity: Scientific American Magazine

X
Scientific American MIND iPad

Tap into your MIND

Get Both Print & Tablet Editions for one low price!

Subscribe Now >>

X

Please Log In

Forgot: Password

X

Account Linking

Welcome, . Do you have an existing ScientificAmerican.com account?

Yes, please link my existing account with for quick, secure access.



Forgot Password?

No, I would like to create a new account with my profile information.

Create Account
X

Report Abuse

Are you sure?

X

Institutional Access

It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. To access this article in its entirety through site license access, click below.

Site license access
X

Error

X

Share this Article

X