Exam 11: The Origin and Evolution of Early Life

The conditions in the Miller-Urey experiment produced amino acids but not peptides. Subsequent experiments have adjusted the conditions and have produced other amino acids and stable peptide bonds. What is the biological significance of stable peptide bonds?

Which of the following is a reason DNA is favored over RNA as genetic material?

What is LUCA and why is it possible that life originated before LUCA existed?

If horizontal gene transfer was predominant in early evolution, how would this affect our ability to reconstruct the tree of life?

Why does the theory of evolution NOT explain the origin of life?

Which of the following was NOT a source of molecules in the "prebiotic soup"?

The figures below illustrate two lineages with two variants: one dark gray and one pale gray. The arrows point to the descendants of the individual. Natural selection could act on the lineage on the A B

A phylogenetic event horizon is a

Many proteins are now thought to consist of modular units that can, through exon shuffling, form new proteins. How is this situation analogous to what may have occurred in the earliest life-forms?

How did Spiegelman et al.'s experiment on the origins of natural selection provide evidence for natural selection in an RNA-based world?

Natasha Paul and Gerald Joyce's experiment sought to provide evidence that supported the theory of RNA world. To show evolutionary change, there had to be variation in RNA sequences, the ability to reproduce or replicate themselves, and fitness differences between sequences. This schematic of the results illustrates which specific requirement for evolutionary change that Paul and Joyce were studying? A B

Which of the following is NOT a hypothesis for the origin of viruses?

When life first evolved, ocean temperatures were ________ and there was ________ atmospheric oxygen.

List the properties typically associated with living organisms.

Why did the researchers conduct serial transfers in the experiment illustrated in the figure?

What was LUCA?

When researchers are trying to identify a minimal gene set, which characteristic is most critical for identifying which genes constitute the minimal gene set?

Why can we not use modern atmospheric conditions to infer the origin of life?

Identify all potential energy sources for prebiotic chemical reactions depicted in the figure.

To understand minimal gene sets, Csaba Pal et al. (2006) deleted genes to determine fitness effects in E. coli. How were fitness effects measured?