Bio-Technology and Evolution

Gel electrophoresis

sorts DNA fragments by size; uses electricity to move fragments through agarose gel

PCR

polymerase chain reaction; amplifies the DNA (purpose: to make lots of DNA)

Restriction Enzymes

cut DNA at restriction/recognition site

What are restriction enzymes made of?

made of bacteria -- helps fight of viruses

Restriction site

sequence of bases -- palindrome (reads the same forward and backward)

Protein hormons

insulin and growth hormone

Type 1 Diabetes

an autoimmune disease where no insulin is made

Recombinant DNA

DNA of two or more species

Vectors

Methods of delivery for DNA

What are some examples of vectors?

Plasmid (bacteria), gold bead/air gun, viruses

Plasmid

Circular ring of DNA

Transgenic

Organism with two or more DNA from different species

How do you make insulin to give a person with Type 1 Diabetes

You need to take a non-human organism and give in a human gene

Edited mRNA

No introns

Reverse transcriptase

the opposite of transcription, turns RNA into DNA making cDNA

cDNA

copied DNA without introns

Selective breeding

Humans pick and choose organisms that can reproduce based on traits we want

Inbreeding is also called what?

pure bred

Breeding two different organisms or hybridization results in what?

The best traits of both organisms

Natural selection

the traits that allow organisms to survive will get passed on and the trait will increase within the population

Evolution

change overtime in a species

Who can’t evolve?

Individuals/ single organisms

What is the mechanism for evolutions?

Natural selection -- the environment decides what the best trait is

What was Darwin’s famous idea?

Natural selection

What were the beliefs that Darwin has to fight against?

The earth was a few thousand years old and that there was no change/organisms were perfect

Jean Baptist Lomark

published in 1809, use + disuse/inheritance of aquired characteristics, NEED

Weisman

took mice and cut off their tails but kids had tailed thereby disproving Lomark

Charles Lyell/ James Hutton

Said the earth changes and that it’s 3-4 million years old

How did Lyell/ Hutton influence Darwin?

Darwin thought that if the earth can change, why can’t the creatures on it

Alfred Russel Wallace:

Idea of natural selection but no evidence; pushed Darwin to publish his book

Thomas Malthus (economist)

The idea that humans overproduce

What idea of Darwin’s did Malthus influence?

The idea of competition and limited resources

What do you need to have for natural selection?

Variation in every population and competition

What increases the chance of survivability for a species?

Variation

Sexual reproduction

The combination of genes and it causes more variation that asexual reproduction

Survival of the fittest

Need the trait to allow you to survive and reproduce

How should you start any paragraph about evolution?

Due to variation …

Darwin

Change over time in a species

Populations

Same species in the same area

Gene pool

All genes in a population

Alleles

Variants of a gene

Phenotype

Expression of alleles

Genotype

Actual alleles/ genes

Homozygous

Same alleles

Heterozygous

Different alleles

Modern definition of evolution

Change in allele frequency over time in a population

Single gene trait

One gene controls trait

p + q = 1

allele frequency in a population’s gene pool

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

phenotypes/ genotypes\`

What could cause change in allele frequency/ what could cause evolution?

Mutation, Natural selection (selecting agent), sex selection (picking mates based on traits), migration (if genes go in/out of population), random chance (small population)

Genetic Drift

Random chance

What are the two types of genetic drift

Bottleneck and founder effect

Bottleneck

natural disaster reduced population and survival; repopulate but different allele frequencies

Founder effect

caused by one group leaving/migrating and starting a new population

Hardy-Weinberg equilibrium

No evolution occurs

What conditions need to be met for Hardy-Wienberg equilibrium or no evolution to occur?

Large population, no mutation, no migration, random mating, no natural selection

Polygenic trait

Multiple genes code for trait, hundreds of phenotypes; graph: bell curve

Disruptive

Selecting against the means for extremes

Stabilizing

Selecting for means against extremes

Directional

Select for one of the extremes

Speciation

Creation of a new species

Species

A group of organisms that can reproduce and create viable and fertile offspring

What leads to speciation?

Stopping gene flow

Reproductive isolation

stops gene flow between populations

What are the two types of reproductive isolation?

Prezygotic and postzygotic

Prezygotic (before mating)

Geographic isolation, temporal isolation behavioral, mechanical, gametic, habitat

Geographic isolation

Some physical geographic barrier prevents organisms from getting near each other

Temporal isolation

Time

Mechanical Isolation

The physical parts don’t fit together

Gametic isolation

Proteins on egg and sperm don’t match

Postzygotic:

Create sterile offspring, reduced vitality

Fitness

The ability of an individual to survive and reproduce in its specific environment

Variation

Individual characteristics or traits within a specific species

Adaptation

A trait that helps an organism survive and reproduce

Descent with modification

Over long periods of time, natural selection produces organisms that have a different structure, establish different niches, or occupy different habitats

Homologous Structures

Similar in position and structure but not in function, have a common ancestor

Analogous structures

Similar in function but different in structure, no common ancestor

Vestigial structures

Remnants of features that served important functions in the organism’s ancestors

Divergent Evolution

Evolution of two or more species from a common ancestor

Convergent evolution

Unrelated species independently evolve similar traits due to similar environments

Fossils

Remains of an organism that have been preserved by natural processes

Absolute dating

Looking at the half-life of radioactive material, using radioactive or carbon to find the actual age

Relative datong

the science of determining the relative order of past events without determining their absolute age (looking at rock layers)

Comparative embryology

Similarities in early development show common ancestry

Comparative biochemistry

Less amino acid differences -- the more closely related, shows common ancestry, molecular clock--predicts the rate of mutations every 10,000 years

Polygenic traits

A trait controlled by several genes

Punctuated equilibrium

Periods of equilibrium with no change and periods with rapid change

Gradualism

Small changes over long periods of time

Co-evolution

Two organisms that evolve together

Co-evolution example

Bacteria in your stomach keep evolving with you to make sure they can stay in your stomach

How did the earth start?

Hot, 4.6 billion years ago, with no oxygen, water was vapor, took a billion years for anything to happen

What is micro vs macro evolution?

Micro is just the evolution of a population and macro is global-level changes across worldwide species \[mass extinction\]

How to induce mutations?

Lots of chemicals and radiation

Miller/ Urey

No things on earth were going to become life so they took the stuff on the planets in the times (the chemicals in the air), put it in a jar, and zapped it with a lot of energy (there was a lot of energy on our planet). They found that the components transformed into amino acids which are the building blocks of life.

Fox

Did Miller/Urey’s experiment using the right materials

CRISPR

Restriction enzyme on steroids, can program it to go into a cell and cut out parts of genes to replace with the right stuff

Darwin background

Religious perspective (degree in theology), naturalist, his voyage, the scientists that influenced him

Transformation

Putting a new gene into bacteria using a vector

Habitat vs Geographic Isolation

In different habitat nothing standing in way, no reason to leave the habitat and geographic is a physical barrier

How are fossils formed?

Ice and sap can preserve animals, Most fossils are formed by mold and cast, Sediment covers skeleton over many years and eventually it is completely compressed stone, Natural mold: open space made by dissolved bones