Week 7 PEQs

Which taxonomic group of land plants still in existence today was the dominant group of land plants when the angiosperms began their rapid increase in speciation and distribution?

Gymnosperms

The term "protist" lacks phylogenetic accuracy because it represents a paraphyletic group. Which of the following statements reflects the paraphyly of protist taxa?

Some eukaryotic lineages evolved from protists, and they are not called protists.

Mass extinctions have occurred five times in Earth's history. The end Permian and Cretaceous extinctions were responsible for removing a large percentage of organisms from the planet. How do these extinctions contribute to the biodiversity we see today?

Species that remain after the extinction are able to radiate, new adaptations arise, and these produce the diversity seen today.

How is it possible that phylogenies based on sequences from nuclear genomes and organellar genomes (i.e., chloroplasts and mitochondria) from the same group of species yield phylogenetic trees with different branching orders?

The genome of the endosymbiont is more closely related to members of the group in which it originally evolved, while the nuclear genome of the engulfing organism has its own evolutionary trajectory.

Which of the following is true regarding the history of life on Earth

The history of planet Earth includes alternations between colder periods ("icehouses") and warmer periods ("greenhouses") on the surface of the planet. There have been repeated incidents of mass extinction in the history of the planet in which species diversity has been reduced by 50% or more. There is more oxygen in the atmosphere today than there was early in Earth history.

The fossil record is testament to extinct fauna no longer present on Earth. Certain areas of the planet have always had high species diversity (evidence from fossils and catalogs of current species diversity). Which of the processes listed below likely contributed to the patterns of animal diversity we see?

extinction events (both local and global)

According to this phylogeny, which of the following CORRECTLY lists the sequence in which multicellularity, tissues, and bilateral symmetry arose, from the oldest characteristic to the most recent?

multicellularity, tissues, bilateral symmetry