Unit 7: Evolution (Biology)

Hadean Eon

1st major eon. Hell on Earth. No forms of life.

Archean Eon

2nd major eon. First form of life.

Proterozoic Eon

3rd major eon. Transition to eukaryotes from prokaryotes. Post Oxygen Revolution

Phanerozoic Eon

4th major eon (right now). Massive explosion in diversity.

Biogenesis

all living things come from other living things

Spontaneous Generation

a process by which living things come from nonliving things

Francesco Redi's Experiment

proved that life doesn’t just appear from the right conditions

Lazzaro Spallanzani's Experiment

believed air was what led to life

Louis Pasteur's Experiment

proved that it wasn’t air, but the things in the air that led to life.

Oparin-Haldane Hypothesis

proposed a gradual, step-by-step process of "chemical evolution"

Abiogenesis

life arising from simple organic compounds

RNA WORLD

The RNA World Hypothesis states that the first molecule of genetic storage was not DNA, but RNA!

Shallow clay pools

a hypothesis on how life originated. this allows for the concentration of nutrients in one specific area, and the water evaporates out but the organic molecules remain.

Hydrothermal vents

a hypothesis on how life originated. mantle of the earth is in contact with the ocean there, and there is a LOT of life there, completely cut off from the sun. There’s no photosynthesis, but there is chemosynthesis. They use the chemicals in the water and convert it to sugars. Photosynthesis did not evolve until the oxygen revolution

Panspermia

life elsewhere in the universe, came to Earth, and kick-started the evolution of life on Earth

HOMOLOGOUS STRUCTURES

Other scientists focused on homologous structures, similar features that originated in a shared ancestor that evolved over time

Analogous structures

have very similar functions and may look alike, but are developmentally and structurally different. This is NOT evidence of evolution.

VESTIGIAL STRUCTURES

Vestigial structures were, at one point in time, useful structures to an evolutionary ancestor, but through evolution, are no longer necessary to the organisms that have them.

EMBRYOLOGY

Similarities in embryology show a shared common ancestor between all vertebrates because of a similar developmental pattern.

MACROMOLECULES

Macromolecule (DNA/RNA protein) similarities show that all living things have a similar blueprint and share similar genes.

BIOGEOGRAPHY

Shows how plants and animals spread across the planet, and how certain species are related to others. Similar organisms may occur in very far places because of them having a similar ancestor back when the continents were together as Pangea.

FOSSIL RECORD

another evidence of evolutionary change

Evolution

genetic changes in a population of organisms over time

Selection

is the survival and reproduction of individuals with certain traits.

Fitness

is the ability of organisms to survive and reproduce for the next generation

Artificial Selection

Humans select the traits of plants and animals that are passed onto the offspring.

Natural Selection

Nature selects the traits that get passed to the next generation.

Sexual Selection

A type of natural selection where the best traits increase the chances of successfully having offspring.

Random Selection (genetic drift)

is when a trait survives because it was chosen at random.

balanced polymorphism

Maintenance of two or more alleles of a gene at high frequency in a population.

frequency-dependent selection

Natural selection in which a trait's adaptive value depends on its frequency in a population.

sexual dimorphism

A trait that differs between males and females of a species.

bottleneck

Reduction in population size so severe that it reduces genetic diversity.

fixed

Refers to an allele for which all members of a population are homozygous.

founder effect

After a small group of individuals found a new population, allele frequencies in the new population differ from those in the original population.

gene flow

The movement of alleles between populations.

genetic drift

Change in allele frequency due to chance alone.

inbreeding

Mating among close relatives.

Directional selection

For one extreme trait, against the other extreme

Stabilizing selection

For the middle trait, against the extremes

Disruptive selection

For both extremes, against the middle

Population Genetics

the study of evolution from a genetic perspective, focusing on the change of allele frequency over time

Gene Pool

The total genetic information available in a population.

Genotypic Frequency

how often a specific genotype occurs in a population

Allele Frequency

the proportion of a specific allele in a population

Hardy Weinberg Equilibrium

*A null hypothesis* - hypothesizes that NOTHING is happening. If proven incorrect, __then something (evolution) is happening__

5 assumption of HWE

\

1. no mutation
2. no migration
3. no genetic drift
4. no sexual selection
5. no natural selection

Hardy Weinberg Equation

p^2+2pq+q^2=1

Order of hierarchy

1. domain
2. kingdom
3. phylum
4. class
5. order
6. family
7. genus
8. species

Acronym to remember taxonomy classification

Does King Phillip Come Over For Good Soup

Steps needed for life:

1. simple organic molecules
2. self replicating RNA
3. RNA molecules contained in cell membrane
4. metabolism that generated energy

First life forms were:

1. prokaryotic
2. anaerobic
3. heterotrophic
4. unicellular

**Descent with Modification**

Newer forms of organisms appearing in the fossil record (and in modern times) are the modified descendants of older species. One of the theories in natural selection by Charles Darwin.

***Morphological Species Concept***

***Based on external appearance. Problematic because some species look very alike.***

***Biological Species Concept***

A certain species can only successfully interbreed with their own, and not other groups. Problematic because some species were extinct, asexual organisms

Allopatric

different country

Peripatric

about/all around country

Parapatric

near country

Sympatric

same country

Phylogeny

the evolutionary history of a species.

phylogenetic

the study of evolutionary relationships among biological entities - often species, individuals, or even genes.

clade

A group whose members share one or more defining derived traits.

cladogram

Evolutionary tree diagram that shows evolutionary connections among a group of clades.

derived traits

A novel trait present in a clade but not in any of the clade’s ancestors.

phylogenetic tree

Diagram showing evolutionary connections.s

sister groups

The two lineages that emerge from a node on a cladogram.

Alfred Russell Wallace

was second in publicizing his findings on natural selection, so Darwin got to it first.

Georges Cuvier

proposed the idea that some species have gone extinct after finding fossils that did not look anything like any currently living organisms.