Evolution theory

Question 1

Micro-Evolution

Answer 1

small-scale changes within a species. Changes that occur within a species from one generation to the next. These changes are passed on to offspring. This results in genetic diversity in populations. The timescales involved for micro-evolution are typically days to thousands of years.

Question 2

Macro-Evolution

Answer 2

the development of new species from earlier species over many many generations. This results in species diversity in different ecosystems. The timescales involved for macro-evolution are typically millions of years to billions of years.

Question 3

What evidence is there for the theory of Evolution?

Answer 3

Fossils and the fossil record

Descent with modification - homologous characteristics

Biogeography

Genetics

Question 4

Fossil record:

Answer 4

An accumulation of all known fossils of different ages for a particular area.

Question 5

Descent with modification

Answer 5

Equivalent structures with the same body plan that might perform different functions are called homologous structures or characteristics. These structures provide evidence of evolution since the same structure can be traced back to a common ancestor. Examples of homologous structures: fur on mammals (e.g. cats and kangaroos); limbs on tetrapods (e.g. frogs, lizards, and dogs); parallel leaf veins in monocots (e.g. grasses and onions); flowers in angiosperms (e.g. hibiscus and daffodils).

Question 6

Comparative biochemistry

Answer 6

The molecular composition of all living organisms is very similar. Essentially the same metabolic processes, enzymes and cell structures represent homologous characteristics on a cellular scale. These confirm the theory of evolution by showing that certain living organisms have common ancestors.

Question 7

The following evidence is used for the common ancestry of all of life:

Answer 7

Identical DNA structure

Identical process of protein synthesis (transcription and translation)

The same 20 amino acids used to build proteins

The same metabolic processes and enzymes e.g. for respiration

ATP is the universal energy carrier

Phospholipid membranes common to all organisms

Question 8

BIOGEOGRAPHY

Answer 8

Biogeography is the study of the distribution of extant and extinct species. It is seen that closely related species usually are found in the same geographical region, suggesting a common ancestor in that region.