Species Richness is Greatest at Which Latitude

Question

Species richness is greatest at which latitude?  
A) 60 degrees north
B) 60 degrees south
C) 0 degrees
D) 40 degrees north
E) 20 degrees south

Accepted Answer

Studies have shown that species richness is highest at the equator (0 degrees). This phenomenon is known as the "latitudinal gradient in species diversity". This is believed to be due to a combination of several factors, including stable equatorial climates that provide year-round productivity, higher productivity due to greater sunlight intensity, and reduced environmental variability. As you move away from the equator towards the poles, species richness generally decreases.