Environmental Science 4 (Evolution, Biodiversity, and Extinction)

New channel Earth and Space Sciences X: title sample judged 'whole' (A professor's genuine full-length geology/environmental science lecture series plus thoughtful field explainers, with on); passed a second screen for sellers/exam-prep/re-uploads; 1 of 3 sampled transcripts showed teaching, 0 not; every title checked strictly; oEmbed verified.