BIOL 1407 Exam 1 Open Ended

HWE Assumptions (5)

-No gene flow

-no natural selection

-no sexual selection

-no mutations

-large populations

Darwin’s Observations

• heritable traits get passed down to offspring

• each population can have large population for growth, but that growth is limited because of resources

• not all young survive because of competition

• possessors of some traits will survive

• variations most advantageous will accumulate

Punctuated Equilibrium

long stretches of little to no change (stasis), punctuated by short, rapid bursts of divergence when new species do appear

3 forms a mutation can take + most and least common

beneficial (least), inactive (most), deleterious

3 Forms of Selection

Stabilizing, Directional, Disruptive

Explain how it is hypothesized that the human hemoglobin gene family arose.

When the ancestoral globin was copied, there was an error in crossing over which resulted in two pairs of an ancestoral globin on the same chromosone. This error occurs when the chromsones are not lined up properly and they transfer genes. Then, a mutation occured which resulted in an alpha globin and beta globin. Then, through transposable elements the alpha and beta were copy and pasted on to different chromsones. The process repeated, so in the alpha family they were duplicated, but errors in crossing over occured which resulted in different types of alpha on one chromosone. Same thing happened to the beta family.

High Resolution Timeline, what happened first

Hadean 4.6-4.0 BYA 

High Resolution Timeline, what happened second

Archaean, 4-2.5 BYA

High Resolution Timeline, what happened third

Protozoic, 2.5 BYA-450 MYA

High Resolution Timeline, what happened fourth

Phanerozle, 450 MYA- Present

Traits of Protozoic

-snowball Eath 1, edicarian multicellular, snowball 2

What’s within Phanerozle

Palezoic (450-251 MYA), Mesozix (251-65 MYA), Cenozic (65 MYA to present)

Palezoic Traits

1. Cambrian explosion 

2. all major phyla in aquatic communities 

3. Terrestrial colonization 

4. invertebrates, plants and fungi, vertebrates 

5. radiation of reptiles, mammal lineage, mass extinction 

Mesozoic Traits

1. seed bearing plants, dinosaurs and other great retile lineages 

2. mammals, flowering plants, insects 

3. mass extinction 

Cenozoic Traits

1. birds 

2. mammalian and angiosperm radiation 

3. insect radiation 

4. primate radiation 

5. ‘small’ ice ages in the Cenozoic versus snowball earth from Proterozoic 

Organize these major events in the history of life using a scale diagram with

rough dates in BYA or a narrative (descriptive) sentence connecting them:

A) appearance of oxygen in oceans

B) appearance of eukaryotic cells

C) appearance of autotrophic prokaryotes

D) appearance of multicellular animal life

E) appearance of heterotrophic prokaryotes

F) appearance of dinosaurs

Appearance of heterotrophic prokaryotes (3.8 BYA), autotrophic prokaryotes (3.5 BYA), appearance in oxygen (2.3 BYA), eukaryotic cells (2.2 BYA), multicellular animal life (600 MYA), dinosaurs (230 MYA)

Cenozoic Traits

1. birds 

2. mammalian and angiosperm radiation 

3. insect radiation 

4. primate radiation 

5. ‘small’ ice ages in the Cenozoic versus snowball earth from Proterozoic