The Impact of Biology on Society

Preserving our Environment

• More than 7 billion people live on Earth.

All of these people need room for

• Housing• Water• Food• Work• Waste

The large human population has created stress in the environment• Tropical rainforests are home to ½ of the world’s species of

plants and animals.

• About 1 acre/second of rainforest is destroyed

• The destruction of rainforests is leading to large extinctions.

Conservation biologists try to find a balance between humans and preserving the environment

• They find ways to reuse waste• The French fry example from your book

• Research more efficient ways of using land• Better ways of designing housing developments• Better means of transportation

Improving the Food Supply

• 842 million people worldwide suffer from not having enough food to eat

• Droughts and lack of food lead to a lot of civil unrest

• The severe drought in the US is predicted to cause increased unrest in Africa and Asia

Modern Agricultural Scientists use Genetic Engineering to Improve Food Supply• Biologists have learned to move genes from one organism to

another

• The change is permanent• The gene is now part of the crop’s DNA forever

Some advantages from genetic engineering•Makes plants resist insect pests• Herbicide resistant• Fields with fewer weeds use less water

• Improved nutrition

• Better protein content

New Ideas in Transgenic Plants

• Golden Rice• Rice with added Vitamin A• Improves vision in millions of people

• Adding vaccines to bananas

• Adding genes to keep food from spoiling after it is picked

Human Genome Project

• Due to improvements in technology, the US government and private research companies decided to sequence the human genome in the 1990s

• A genome is all of the genetic material in an individual

• The human genome then contains all human genes.

Human Genome Project

• We now have a sequence for every human gene

• We are beginning to attach functions to each gene

• By comparing genomes between individuals, we can help predict what diseases they may be at risk for.

Fighting Disease

•AIDS is caused by HIV•HIV is a virus that attacks the human immune

system•Because it is a virus, anti-biotic drugs don’t work•Because it attacks the immune system, your body

can’t attack it either

HIV mutates very rapidly

• Vaccines target specific proteins•What proteins look like is determined by DNA sequence• The virus’s DNA changes a lot, so the proteins change a lot

• New vaccines are targeting more than one protein at a time

Cancer

• About 600,000 people died of cancer in the US last year.

• That is approximately 2% of the population

• 1 in 4 deaths in the US each year are from cancer

• Cancer incidence is growing rapidly

What is cancer?

• Cancer cells have mutation(s) that cause them to divide out of control

• This out of control growth leads to tumors.

Modern Research and Cancer

•We know now how to avoid many cancers.• Anti-smoking ads have been effective in reducing numbers

of smokers

•We have identified the genes associated with many cancers• This helps people identify their risk•We can target drugs to the proteins made by these genes

Emerging Disease

• Climate change and increased human migration have made it easier for diseases to travel around the world

• The US has seen diseases on its soil for the first time• West Nile• Mad Cow• Ebola

The problem with new diseases

•We don’t know which ones will take off• In the early 1980s, HIV was an emerging disease• It has since killed millions of people

•Many of them are viruses

•We don’t know how to fight them or, sometimes, even how they spread

Gene Therapy

• Some diseases are caused by a bad copy of a gene• The proteins the DNA makes are made wrong and can’t work

• The idea of gene therapy is to put a functional copy of the gene in the person

Diseases for Gene Therapy

• Cystic Fibrosis• The body creates too much, very thick mucous• It kills organs like the lungs

•Hemophilia• Patients can’t make blood clotting factor and could

theoretically die from a bruise