A breed of finches are born with a variety of beak sizes. The birds with smaller beaks can eat smaller seeds. The finches with larger beaks can eat larger seeds. Which environmental change would best explain an increase in the number of birds born with a smaller beaks?

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.

multiply it by 5 in order for you to understand i cant give an exact answer.