Astudy of the human gut performed in 1982 used various types of plates under different growth conditions to describe and enumerate the microbes in the human gut. they concluded that the majority of the microbes in the human gut are gammaproteobacteria. a study conducted in 2010 using next-generation sequencing to characterize 16s rrna sequences concluded that the majority of the microbes in the human gut are firmicutes and bacteriodetes. why did these studies have different conclusions? which study do you think is most accurate?

Ameadow ecosystem includes many species of grasses and small shrubs, several herbivores, and a few carnivores. a fungus colonizes the meadow and kills most of its vegetation. what is most likely to happen to the populations of herbivores and carnivores in the ecosystem? a. the populations of herbivores and carnivores will increase because there will be less competition for chemical energy. b. the populations of herbivores and carnivores will remain stable because the fungus cannot infect these organisms. c. the populations of herbivores will decrease because of vegetation loss, but the population of carnivores will remain stable. d. the populations of herbivores and carnivores will decline because less chemical energy will be stored in the ecosystem.

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution