Biology, Topic 4 - Natural Selection and Genetic Modification

Alfred Russel Wallace

A scientist that came up with the idea of natural selection, independently of Darwin. Although his proposed mechanism differed, his observations provided further evidence to support the theory.

Antibiotic

resistant bacteria

Archaea

One of the three domains. It consists of primitive bacteria existing in extreme environments.

Ardi

A 4.4

Bacteria

One of the three domains that consists of true bacteria.

Carbon

14 dating

Charles Darwin

The scientist who developed the theory of evolution by natural selection.

Classification

The organisation of organisms into groups based on their characteristics and structure.

Competition

When different organisms compete for the same resources (e.g. light, water, mates, territory) in an ecosystem. This limits population size and stimulates evolutionary change.

Eukarya

One of the three domains that consists of all eukaryotic organisms.

Evolution

The gradual change in the inherited traits within a population over time. Occurs due to natural selection.

Five kingdom classification system

The classification of organisms into five major kingdoms: Animalia, Fungi, Plantae, Prokaryotae and Protoctista.

Fossils

The remains of dead organisms found in rocks which are millions of years old.

GM Organism

An organism that has had its genome altered.

Genetic engineering

The modification of the genome of an organism by the insertion of a desired gene from another organism, enabling the formation of organisms with beneficial characteristics.

Genome

The complete genetic material of an organism.

Ligase

An enzyme that joins the sticky ends of the DNA and vector DNA forming recombinant DNA.

Lucy

A 3.2 million year old female hominid fossil exhibiting more human

Mutation

A random change in the base sequence of DNA which may result in genetic variants. Mutations may be beneficial, damaging, or neutral.

Natural selection

The process by which the frequency of advantageous traits passed on in genes gradually increases in a population over time.

Recombinant DNA

A combination of DNA from two different organisms.

Restriction enzymes

Enzymes that cut DNA molecules at specific sequences, creating sticky ends.

Richard Leakey

A scientist that discovered many hominid fossils on an expedition to Kenya, including the 1.6

Selection pressures

Environmental factors that drive evolution by natural selection and limit population size, e.g. competition, predation and disease.

Selective breeding

The process by which humans artificially select organisms with desirable characteristics and breed them to produce offspring with desirable phenotypes.

Sticky ends

The staggered cut formed by restriction enzymes in double

Stratigraphy

Using the age of the layers of sediment surrounding archeological remains to estimate the age of the remains.

Taxonomy

The classification of organisms into taxa: kingdom, phylum, class, order, family, genus, species.

Three

domain system

Tissue culture

A method of growing living tissue or cells in a suitable medium to produce clone plants.

Vector

A carrier used to transfer a gene from one organism to another.