https://www.pnas.org/content/118/44/e2111876118

Skip to main content

Main menu

  * Home
  * Articles
      + Current
      + Special Feature Articles - Most Recent
      + Special Features
      + Colloquia
      + Collected Articles
      + PNAS Classics
      + List of Issues
      + PNAS Nexus
  * Front Matter
      + Front Matter Portal
      + Journal Club
  * News
      + For the Press
      + This Week In PNAS
      + PNAS in the News
  * Podcasts
  * Authors
      + Information for Authors
      + Editorial and Journal Policies
      + Submission Procedures
      + Fees and Licenses
  * Submit

  * Submit
  * About
      + Editorial Board
      + PNAS Staff
      + FAQ
      + Accessibility Statement
      + Rights and Permissions
      + Site Map
  * Contact
  * Journal Club
  * Subscribe
      + Subscription Rates
      + Subscriptions FAQ
      + Open Access
      + Recommend PNAS to Your Librarian

User menu

  * Log in
  * My Cart

Search

Search for this keyword 
[                                                            ]
Search 
  * Advanced search

Home
Home

  * Log in
  * My Cart

Search for this keyword 
[                                                            ]
Search 
Advanced Search

  * Home
  * Articles
      + Current
      + Special Feature Articles - Most Recent
      + Special Features
      + Colloquia
      + Collected Articles
      + PNAS Classics
      + List of Issues
      + PNAS Nexus
  * Front Matter
      + Front Matter Portal
      + Journal Club
  * News
      + For the Press
      + This Week In PNAS
      + PNAS in the News
  * Podcasts
  * Authors
      + Information for Authors
      + Editorial and Journal Policies
      + Submission Procedures
      + Fees and Licenses
  * Submit

New Research In

Physical Sciences

Featured Portals

  * Physics
  * Chemistry
  * Sustainability Science

Articles by Topic

  * Applied Mathematics
  * Applied Physical Sciences
  * Astronomy
  * Computer Sciences
  * Earth, Atmospheric, and Planetary Sciences
  * Engineering
  * Environmental Sciences
  * Mathematics
  * Statistics

Social Sciences

Featured Portals

  * Anthropology
  * Sustainability Science

Articles by Topic

  * Economic Sciences
  * Environmental Sciences
  * Political Sciences
  * Psychological and Cognitive Sciences
  * Social Sciences

Biological Sciences

Featured Portals

  * Sustainability Science

Articles by Topic

  * Agricultural Sciences
  * Anthropology
  * Applied Biological Sciences
  * Biochemistry
  * Biophysics and Computational Biology
  * Cell Biology
  * Developmental Biology
  * Ecology
  * Environmental Sciences
  * Evolution
  * Genetics
  * Immunology and Inflammation
  * Medical Sciences
  * Microbiology
  * Neuroscience
  * Pharmacology
  * Physiology
  * Plant Biology
  * Population Biology
  * Psychological and Cognitive Sciences
  * Sustainability Science
  * Systems Biology

Page Not Found

The requested page "content/118/44/e2111876118" could not be found.

Site Logo
Powered by HighWire

  * Submit Manuscript
  * Twitter
  * Youtube
  * Facebook
  * RSS Feeds
  * Email Alerts

Articles

  * Current Issue
  * Special Feature Articles - Most Recent
  * List of Issues

PNAS Portals

  * Anthropology
  * Chemistry
  * Classics
  * Front Matter
  * Physics
  * Sustainability Science
  * Teaching Resources

Information

  * Authors
  * Editorial Board
  * Reviewers
  * Subscribers
  * Librarians
  * Press
  * Cozzarelli Prize
  * Site Map
  * PNAS Updates
  * FAQs
  * Accessibility Statement
  * Rights & Permissions
  * About
  * Contact

[logo-nas-w]

Feedback    Privacy/Legal

Copyright (c) 2021 National Academy of Sciences. Online ISSN 1091-6490.
PNAS is a partner of CHORUS, COPE, CrossRef, ORCID, and
Research4Life.