Human Impact on Genetics Notes

*Humans understand that some traits in organisms are more desirable, and find ways to produce those traits in offspring*

Artificial Selection—humans select which plants/animals breed to pass on desired traits

people choose to organisms with desirable traits to get offspring with a higher likelihood of having those traits

Animal Husbandry (aka Selective Breeding)—farmer chooses to breed animals with desirable traits

one type of artificial selection
- Example: choosing cows that produce the most milk to breed, while not allowing cows that produce the least milk to breed
  - increases the quality and quantity of milk from later generations
- Fruits/veggies—cross specific plants to increase the size, flavor, and amount produced in each later generation

Genetic Engineering—research field that tries to change the genetics of living organisms to have more desirable traits

create crops that are less easily damaged; increase amount produced; create better taste; increase the shelf life of produce
allows the growth of more food using less land
- insulin—a hormone used to help body use sugar, not produced properly in people with diabetes
  - can now create insulin by inserting the human gene for producing insulin into bacteria; the bacteria follows the genetic blueprint and creates insulin, which we can harvest to help people with diabetes

Cloning—an exact genetic duplicate of a living organism is grown –born at a later time

DNA from a cell of a female is inserted into the egg of another female
complete DNA code is inserted (instead of half), so egg thinks it’s fertilized and grows into a new organism
clones have to grow, develop, and learn just like the original (aren’t made full-grown like in sci-fi movies)
the environment the clone grows in can change how its traits are expressed, causing slight differences between the original and the clone
- ie: diet/pollution/etc can affect growth
Dolly the Sheep was the first mammal ever cloned
- died relatively young due to lung disease and extreme arthritis
- used to believe clones tended to be susceptible to illness, don’t live long (weak immune systems)...Dolly's clones suggest otherwise

*Is cloning right or wrong? –produce better food, but ethical problems with cloning people

Therapeutic Cloning: cloning of organs to replace damaged/diseased organs

Gene Therapy—insertion of a gene into a person’s cells to cure genetic disorders

can’t be used to cure viruses, only genetic ailments present from birth
Uses a vector (“carrier molecule”) for the gene
- incorporates the desired gene into patient’s DNA
- still experimental