[R] bringing worldclim data into R

[Lori12]

Hi,
I'm going to try to do some species distribution modeling in R using
Mahalanobis distance. I have presence point locations for the species
and I have ASCII files for each of the WorldClim variables for North
America. My question is how do I bring these into R?
If this is too complex, I have done an extract multi values to points
function in ArcInfo and have the values for each climate variable for
each point location (many columns/fields of data). Would it be better
to work with just the single shapefile that contains point lat/long as
well as all the climate values? I'm just learning R so apologies if
this is a stupid question.
Thanks,
Lori