B4 natural selection and genetic modification

just some stuff i need to remember

ARDI

4.4 MYA

small skull

large hands and feet

long arms

opposable thumbs

LUCY

3.2 MYA

walked upright

arched feet for walking

still small skull volume

LEAKEY

1.6 MYA

skeleton similar to modern humans

larger skull volume

STONE TOOLS PHRASE

assume stone tool is as old as rocks around it, and age of rocks around it can be determined by carbon dating. however can identify age of stone tools using stratigraphy - the study of rock layers, with older rocks being deeper, and newer rocks being nearer the surface.

DARWIN AND WALLACES THEORY

• darwin and wallace both observed that there was variation in populations, and some had characteristics that made them more suited to their environments

• darwin observed this by looking at finches in the galapygos for five years

• published research together, however darwins ‘on the origin of species’ in 1859 got more recognition

HOW DOES DARWIN’S AND WALLACE’S THEORY INFLUENCE MODERN BIOLOGY

• changed how we classify organisms, as we understand we all evolve from common ancestor. organisms most genetically similar put together

• changed how we prescribe drugs as we know about the dangers of antibiotic resistance and bacteria evolves

• changed how we view conservation as we understand it is important to preserve genetic variety which allows species to adapt to changing environments

PENTADACTYL WING

same structure for totally different functions shows different species have evolved from a common anscestor, rather than being designed for different functions individually

5 KINGDOMS - based off appearance and characteristics

• animals

• plants

• fungi

• protists (unicellular, nucleus, cell wall)

• prokaryotes (unicellular, no nucleus, cell wall)

WHERE WAS ARCHEA PUT AND WHY

Initially in the prokaryotes as it was

• unicellular

• had no nucleus

BUT IT’S DNA WAS SIMILAR TO PLANTS AND ANIMALS!

3 DOMAINS (BAE) - based of genetic sequencing

• bacteria - unicellular, no unused sections

• archea - unicellular, unused sections

• eukarya - multicellular, unused sections

SELECTIVE BREEDING

the breeding together of organisms with certian characteristics and over many generations produce a new breed or variety

• disadvantage = may loose alleles that may be useful in the future, reducing gene pool, and huge numbers of same variation are succeptible to disease

GENETIC MODIFICATION

the intriduction of a new gene into an organisms genome. organisms genome is modified to introduce a new desireable characteristic

• bt toxin was a gene from soil bacterium was added to crops as a natural insectaside, it only affects pests that chew crops! increases yield!

• disadvantages

• may transfer resistant gene onto wild plants

• insects may become resistant to gmo crops

• don’t know long term health risk

• advantages

• can be used to increase food production

SOLUTIONS TO GROWING POPULATION

• fertilisers

• biological control (uses predators to reduce pest numbers)

• good stuff

  • increases yield

  • increases growth

  • less land used

  • less harmful to wildlife (biological control)

• bad stuff

  • pollutes the environment, eutrophication

  • introducing new organisms can cause problems