Will content loaded by AJAX affect SEO/Search Engines?

Question

i wonder if content loaded dynamically by AJAX affect SEO/ability for search engines to index the page?

i am thinking of doing a constantly loading page, something l

Answer 1

Five years later...

Latest update on SEO AJAX:

As of October 14, 2015

Google now is able to crawl and parse AJAX loaded content. SPA or other AJAX rendered page no longer needed to prepare two versions of websites for SEO.