Biotechnology and evolution

Allowing only those animals with desired characteristics to produce the next generation (has been practiced over thousands of years)

Hybridization and inbreeding

Crossing dissimilar individuals to bring together the best of both organisms.

Crossing individuals w similar characteristics

• allows the unique characteristics to be kept

• Increases susceptibility to diseases and deformities

By introducing mutations (source of genetic mutation)

By exposing organisms to radiation/ chemicals (used on plants and bacteria)

They use their knowledge of the structure of DNA and its chemical properties to change the DNA molecules. Different techniques are used to cut and extract, identify the diff. sequences of DNA and make more copies of DNA.

Changes in DNA

1. Extract DNA

2. Isolate the gene for insulin using a restriction enzyme (cuts DNA at a specific sequence)

3. Creates sticky ends: single strands of DNA produced from the restriction enzyme

4. Extract a ring of DNA: plasmid from a bacterial cell

5. Cut the plasmid with the same restriction enzyme to cut the same sequence

6. Human gene and plasmid combine using DNA ligase

7. Insert recombinant DNA into bacterial cell.

The manipulation of organisms or their components to make useful products.

This is used in DNA technology; modern laboratory techniques for manipulating genetic material.

• modify specific genes

• move genetic info between organisms

scientists combine pieces of DNA from 2 different sources (mostly different species) to form 1 single DNA molecule.

This is used for genetic engineering: the direct manipulation of genes for practical purposes.

• scientists use genetic engineering on bacteria to mass produce a variety of useful chemicals.

small + circular DNA molecule that duplicates separately from larger bacterial chromosomes.

• typically carry a few genes and pass them down

• they are easily manipulated, they can carry any gene

They are used in gene cloning

the production of many identical copies of gene-carrying DNA

• important to genetic engineering.

Cutting tools of bacterial enzymes

• each different enzymes focuses on a different short sequence (restriction site)

• the same restriction enzyme cuts the same restriction fragments from the different DNA

• these fragments can be put back together using DNA ligase

a collection of cloned DNA fragments that include an organism’s entire genome

Viruses that infect bacteria can serve as vectors in cloning.

• when used as a vector, the DNA fragments are inserted into phage DNA molecules

• this recombinant phage DNA can be put back into a bacterial cell through a normal infection process

• The DNA is then replicate

• we use different restrictive enzymes for different recognition sites.

• widely used in molecular biology

• makes millions/billions of copies of a specific DNA

• allows scientists to study a large amount of DNA from a small sample

• Gel + Electricity

• A technique used by forensic scientists to identify individuals by characteristics in their DNA

method used to separate + analyze macromolecules ( DNA + RNA + proteins) based on size and electric.

Contain genes of another organism GMO

• have been used to study genes + improve supply

• livestock have been produced w extra copies of growth hormone genes

• chicken that has resistance to bacterial infections cause food poisoning

1. donor being cloned: harvest one somatic cell → remove nucleus ( 46 chromosomes)

2. donor egg cell: remove nucleus → egg is empty

3. inject donor somatic cell nucleus → egg is empty

4. newly fused egg divides by mitosis → creates embryo

5. embryo placed into uterus

• Gradual change in a species over time

• is the process of descent w modification

all species over time have descended from a common ancestor. The pattern of evolution from natural selection

• 5 year voyage as a naturalist

• collected flora, flauna, fossils

• reads scientific books + articles

• returns to England and studies

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

helps an organism survive and reproduce

results in changes in the traits of the population. Increases their fitness + survival.

Process where the individuals become better adapted to their environment and become more likely to survive + reproduce.

• overproduction

• competition

• variation

• selection

produce more offspring to survive

food space

differences between individuals within the species

the environment selects the organism with the best traits/adaptation for the future

• selective use or disuse of organs

• traits are acquired

• lost during an individuals lifetime

The earth is billions of years old. The processes that change the Earth in the past are the same as now.

human population will grow faster than the space ; food supplies given

The Origin of Species

• comparative anatomy

• fossil record

• geographical distribution of living species

• comparative embryology

• comparative biochemistry

• homologous structure

• analogous structure

• vestigial structure

similar structure but different function (common ancestor)

similar function but different function ( NO common ancestor)

remnants of features that served important functions in organism’s ancestors

Fossils: remains of an organism that have been preserved by natural processes

• many different types of fossils ( petrified in stone, ice, tar, amber)

• gaps in fossil record

• provides evidence of evolution

  • by using time + location

  • absolute dating: using radioactive isotopes to look at the half-life of radioactive materials

• similar animals in different locations were the product of evolutionary descent

• made possible by Pangea

similarities in embryology ( early stages) show a common ancestry

• less amino acid differences -. the closer relation

• shows common ancestry

• molecular clock: predicts the rate of mutations every 10000 years

regular evolution → modern evolution

Darwin’s hypothesis: all life forms are related (molecular biology proves this)

• all forms of life use DNA + RNA

• RNA triplets are translated into amino acids (universal)

• a change in allele frequency over time

different forms of a gene

a large group that can mate and produce fertile offspring

all of the different genes in a population

dominant + recessive

purebred of dominant allele

purebred of recessive allele

# of times the allele occurs in a gene pool compared to the total # of alleles for the gene

outward appearance of an individual

the actual genetic makeup

a trait controlled by a single gene

a trait controlled by several genes

• there is a large population

• no gene flow between populations

• no mutations

• random mating

• no natural selection

• minimal change in environment = stable environment

• rapid change in environment = unstable population

• natural selection ( mutation/variation)

• genetic drift

• gene flow

• similar principles to natural selection

• more focused on mutations/random changes

• 2 types

  • bottleneck effect

  • founder effect

overhunting + habitat destruction

a portion of the population leave to create a new population. There can also be a barrier to divide the population.

It is used to estimate how many people carry the alleles for certain inherited diseases

• Stabilizing Selection

• Directional Selection

• Disruptive Selection

favors intermediate phenotypes

Shifts the overall makeup of the population, by going against one extreme

Environment favors individuals at both ends of the phenotypic range.

• Biological species

• reproductive isolation

• 2 distinct species interbreed and create hybrids

• a group of populations whose members have the ability to interbreed and produce fertile offspring

prevents gene flow, creates a boundary between species

• prezygotic (before mating)

• post zygotic (after mating)

• habitat: lack of opportunity for mates to meet

• temporal: breeding at different times/seasons

• behavioral: failure to send/receive signals

• mechanical: physical compatibility of reproductive

• gametic: incompatibility of eggs + sperm

• reduced hybrid viability

• reduced hybrid fertility

• hybrid breakdown

the initial block to gene flow may come from a geographic barrier that isolates a population.

ex: mountains, canyons, lakes, movement of continents