Darwin analogized the effects of evolution as the above-ground portion of a many-branched tree, with extant species being the tips of the twigs. The common ancestor of two species is most analogous to which anatomical tree part?

#Question id: 9239

#Unit 9. Diversity of Life Forms

Why are changes in the global carbon cycle important?

#Question id: 9240

#Unit 9. Diversity of Life Forms

Use the following figure to answer the question.

Looking at the figure, what can you conclude about the data?

#Question id: 9241

#Unit 9. Diversity of Life Forms

The main goal of sustainable development is to ________.

#Question id: 9242

#Unit 9. Diversity of Life Forms

Eutrophication is often caused by excess limiting-nutrient runoff from agricultural fields into aquatic ecosystems. This process results in massive algal blooms that eventually die and decompose, ultimately depleting the dissolved oxygen, killing large numbers of fish and other aquatic organisms. Predict which of the following human actions would best address the problem of eutrophication near agricultural areas?

#Question id: 9243

#Unit 9. Diversity of Life Forms

Elevated carbon dioxide levels have been shown to contribute to the greenhouse effect, resulting in an increase in mean global temperature. Ecosystems where the largest warming has already occurred include snow-covered northern coniferous forests, tundra, and arctic sea ice habitats. Which statement best explains how the elimination of ice-covered ecosystems affects the rise or fall in global temperature?

#Question id: 9244

#Unit 9. Diversity of Life Forms

One characteristic that distinguishes a population in an extinction vortex from most other populations is that