How can natural selection account for the long tongues of butterflies?

Gabriel is at a stage where his body is changing physically; he is growing facial hair and building muscle. he is also just starting to make sperm. what is most likely gabriel’s age? 5 12 17 21

What is the most common structure of volcanoes?

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?