North America comet theory questioned
No evidence of an extraterrestrial impact 13,000 years ago, studies say.
Protein-design papers challenged
Reanalysis does not find same results as key 2003 study.
nature.com blogs
North America comet theory questioned
No evidence of an extraterrestrial impact 13,000 years ago, studies say.
Protein-design papers challenged
Reanalysis does not find same results as key 2003 study.