Evolutionary Bio - Helm Quiz 1

Scala Naturae

the great scale of being (Plato + Aristotle)

Lamarckanism

Jean-Baptist LaMark in the 1700s; Argues that a species can change over time. Ex. Like a Blacksmith getting strong muscles from his work and his sons inheriting these strong muscles. Ex 2. giraffes w/ long necks grew over time.

inheritance of aquired traits

Saltationism/Mutationism

Early 1800s; large mutational changes within a single generation could create new species. ex. x-men’s mutations. ex 2. plants sometimes

Malthusian Catastrphoe

Where a sudden change of events can cause selective forcing. Europe was going to hit a population peak and start to die off because there weren’t enough resources. His prediction led to the invention of synthetic fertilizer.

Charles Darwin and

1831. Read Mathusian Collapse. Then, came up with his idea: life came from a single ancesters and diversified.

Alfred Wallace read Darwin’s work, and gave him the ideal of Natural Selection, creating the Evolutionary Theory

“fittest”

who can have the most offspring

Orthogenesis

1893; (wrong) straight-line evolution, where organisms are evolving into a “best state” ex. March of Progess is wrong.

The Grand Synthesis

Early 1900s, rediscovery of Mendel’s work + the laws of Mendelian inheritance. This is where genetics and evolution from Darwin merge together. This is how we understand the theories today.

Evolution

Change in the quality or quantity of a trait over time

Character

Identifyable catagorical quality of an organism. ex. A leaf

Trait

Version of a character. Ex. A smooth leaf or a rough leaf

4 types of Evolution + Define them

Sexual Selection (selection based on physical traits), Natural Selection (based on the surroundings), Bottlenecks (a sharp, temporary reduction in the size of a species' population, caused by environmental disasters (such as earthquakes, floods, or fires) or human actions), Genetic Drift (the change in the frequency of gene variants (alleles) in a population over time due to random chance)

Chromosomes

a long single strand of DNA passed down from parent to offspring

Haploid

one chromosome copy per cell (bacteria)

Diploid

two chromosome copies per cell (humans)_

Gene

a specific segment of DNA on a chromosome that encodes for a protein; has start and stop codons

a predictable sequence of nucleic acids but can have a slight variation in a gene’s sequence within a population

Meiosis

process of cell division that creates gamates (sex cells)

Punnent squares

used to examine allele frequency in offsprings

• mendelian traits (dominant and recessive alleles)

homoxygous

two of the same allele: AA or aa

Heterozygous

two different alleles: Aa

Hardy-Weinberg Equalibrium

A theoretical state we can use to evaluate/measure evolutionary rate — if HW is not met, we can assume evolution is occuring.

for no evolution to occur, there must be

• No natural selection

• no sexual selection: random mating

• large/infinite population

• no migration

• no mutation

Hardy Weinberg Formulas

p2 + 2pq + q2 = 1 and p + q = 1

p

frequency of the dominant allele in the population

q

the frequency of the recessive allele in the population

p²

percentage of homozygous dominant individuals

q²

percentage of homozygous recessive individuals

2pq

percentage of heterozygous individuals

locus

the genetic place where a varient occurs

polymorphism

variant form of DNA - inside or outside a gene

Final Observations from Zoe’s presentation

it is good to have genetic variety; when trying to conserve/reintroduce a population, introduce varied populations into the system

• the cutthroat trout were fittest when they had more variation

cross-type success

tests based on observed vs expected

the central dogma in biology

the DNA encodes the RNA, which encodes proteins

• Or, Information gets transcribed into RNA by DNA polymerase, which gets translated into proteins through the ribosomes

DNA information is comprised of…

• 4 nucleic acids

• their order is encoding information

  • 3 letters are grouped together as codons

codon types

• start

• stop

  • various codes for amino acids: the first 2 letters are important and the last third (wobble) matters lesswhy

when do Wobble nucleic acids matter

they can infer when there are mutations and the connections within a population

genomes of a cell

• nuclear genome - 1 per cell, in th enucleus (22 fautosomal chromosomes * 2 pairs each = 44 total + 2 sex chromosomes = 46 total)

  • mitochondrial genome — thousands per cell, in the mitochondria (only passed down through th egg/mom)

Review Chromosomes, Transcription + Translation process