Evolution Exam 1: pre-Darwin, Darwin, and HIV evolution

For Weber State's ZOOL 3720: Evolution

Special Creation Model vs Descent with Modification

Special Creation: Species have existed in their present form, independently from one another, since beginning of time.

• Stems from literal reading of Genesis

• Also states that all species were created relatively recently

Descent with Modification: Species have a common ancestor and change over time

• Evidence based model

• Life on Earth is very old

What was Plato’s Parable of the Cave, how did it fit well with readings of Genesis?

Plato’s Parable of the Cave: Variations in lifeforms (animals) around humans are just shadowy aberrations of “eidos” or the perfect forms

• Parable’s idea of eidos fits well with Genesis’s Garden of Eden, and the perfect forms housed there in.

What did Sir Francis Bacon explore with Logical Structure?

The differences in Inductive and Deductive reasoning

• Inductive: pattern recognition leads to conclusion

• deductive: data collection leads to conclusion (note: data can be collected and/or analyzed poorly)

What did Rene Descart Argue in regards to explaining the natural world?

Everything in the natural world can be explained mechanistically

Nicolas Steno explain about fossils and geology?

• Argued that fossils are the remains of once living creatures

Established three fundamental geological concepts

-Superposition (younger layers on top)

• Original horizontality (layers created horizontally)

• Lateral continuity (layers keep going until something blocks them)

What did Carl Von Linne (Linnaeus) create?

Created a uniform system to name species (taxonomy) which we still use today

what did Georges-Louis Leclerc, Erasmus Darwin, and Jean- Baptiste Lamarck all recognize but could not propose a satisfactory explanatory processes for?

Recognized:

• Species change

• Environment can cause species to change

• There were common ancestors to species groups

They could not provide a satisfactory processes for how species change. (Lamarck proposed a process, but was incorrect, as he claimed acquired traits could be inherited)

What did James Hutton propose in regards to geological processes?

Proposed uniformitarian principle to Royal Society of Edinburgh

• Uniformitarianism- states that the earths geological phenomena can be explained in terms of current observable processes

What were some notable moments in Charles Darwin’s Education Career?

• At 16 Entered Edinburgh University to study medicine

• Switched to Christs College at Cambridge to study for the Clergy (lots of time to be outdoors and interact with nature)

• in 1831 he graduated and knew he did not want to be a Clergy member or a doctor

How did Darwin become a Naturalist on the HMS Beagle?

Through his friend, John Henslow, and his uncle, Erasmus Darwin

What were some of Darwin’s main observations while on the HMS Beagle voyage?

- Flora and fauna of Cape Verde Island, Galapagos etc. connected but different from continental species

- Struggle for survival in the tropical jungles

- Temporal connection of fossilized megafauna and contemporary species in Argentina

- Tectonic activity, marine fossils high in the Andes in Chile

- Seemed like separate species on each of the Galapagos Islands

What two books did Darwin bring with him on the HMS beagle voyage?

• Bible

• Lyell’s Principles of Geology

What year did Darwin publish his book, “Origin of Species by means of Natural Selection”?

1859

What is HIV

• HIV is a retrovirus (RNA virus)

• Parasitizes T-cells, which leads to immune system collapse/AIDS

• Has the highest mutation rate of any virus/organism known to date

What is Azidothymidine (AZT), what does it do, and why does it stop working as a treatment after a few months?

1) AZT is a Thymidine analogue that lacks an OH group at 3’ end

2) Fools HIV enzyme Reverse Transcriptase into adding AZT-Triphosphate instead of Thymidine-Triphosphate, thus halting transcription

3) HIV’s Reverse Transcriptase is extremely error prone, which results in a high mutation rate. Reverse Transcriptase has its active site mutated to lower it’s affinity to AZT, thus making the treatment ineffective.

What is the Transmission Rate Hypothesis and what are it’s assumptions?

Transmission Rate Hypothesis predicts that if transmission of an STD from one host to another is frequent, then natural selection will favor increased virulence.

Assumptions:

• More virulent strains maintain a higher concentration of virons in the blood, and kill the patient faster.

• More virulent strains are more infectious

What is Virulence?

Virulence: Tendency to cause disease in a host

• Largely a function of growth rate

Where did HIV come from?

When SIV jumped hosts to humans

• multiple jumps happened for different strains