A student performed a lab investigation to determine the effect of temperature on the heart rate of a water flea. What is the independent variable in the investigation? * o specie of flea O temperature O heart rate N O size of flea answer

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.