Ground squirrels are found in many areas of the United States. They live in underground burrows and are often attacked by birds of prey, coyotes, and bobcats. Which of the following is a limiting factor for a ground squirrel population? a population of tree squirrels a population of hawks genetic variability breeding season

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.