Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Standardized temporal patterns in pollen morphospecies richness, atmospheric CO2 and temperature. Each data point is the mean of a 1 Myr time-step, then transformed to a z distribution (series mean = 0 and s.d. = 1). Bars represent standard errors of the mean (many are smaller than the symbols). Species richness data are identical in (a,b).
