Classification and Evolution

Classification

The process of naming and organising organisms into groups based on their characteristics

Name the eight groups in the classification hierarchy from largest to smallest

Domain, kingdom, phylum, class, order, family, genus, species

What are the two components to a binomial name?

Genus and species

What is an advantage of the binomial naming system?

It is universal, an organism’s binomial name is the same everywhere in the world

Name the 5 kingdoms and 3 domains

Kingdoms - prokaryotes, protoctista, fungi, plantas, animalia

Domains - bacteria, archaea, eukaryota

How are organisms classified into a kingdom?

Based on similarities in observable characteristics

How was the domain system of classification developed?

By analysing differences between organisms to determine evolutionary relationships (phylogeny)

What is the difference between classification and phylogeny?

Classification is sorting organisms into groups, phylogeny investigates the evolutionary relationships between organisms

Explain how natural selection results in evolution

• random mutations result in new alleles

• some alleles provide an advantage against selection pressures, making an individual more likely to survive and reproduce

• their offspring receive the new allele, an inherit the advantageous characteristic

How did Darwin and Wallace contribute to the theory of evolution?

Observed that birds have many different beak shapes, concluded that birds with beak shapes most suited to the food they eat are more likely to survive and therefore pass this beak shape onto their offspring

What is other evidence aside from Darwin’s theory for evolution?

Fossils - allows us to compare extinct organisms to today’s organisms

Genomic DNA - sequencing of genomes have shown how closely related we are to primates

Molecular - proteins are composed of the same 20 amino acids in all organisms

What causes variation?

Genetic - mutations, random fertilisation

Environmental - climate, diet, culture

Differentiate between intraspecific and interspecific variation

Intraspecific - variation within the same species

Interspecific - variation between different species

Differentiate between continuous and discontinuous variation

Continuous - variation exists as gradual changes over a range eg, height

Discontinuous - variation exists as distinct categories eg, blood group

Why might we calculate a Spearman’s rank correlation coefficient?

To measure correlation between two variable ie, the extent to which changing one variable affects the other variable

Explain how Spearman’s rank results are interpreted

Closer to 1 - more positive correlation

Closer to -1 - more negative correlation

Around 0 - no correlation

What are 3 types of adaptation? (Give examples of each)

Anatomical - change to bodily structure (eg, oily fur)

Physiological - changes to bodily processes (eg, venom production)

Behavioural - changes to action (eg, hibernation)

Why might organism from different taxonomic groups show similar features?

Because they adapted to similar environments

Give some implications of evolution for humans

Bacterial antibiotic resistance means infections are harder to treat, pesticide resistance means entire crops could be destroyed

Differentiate convergent and divergent evolution

Divergent - individuals within a species acquire enough variations in their traits that it leads to two distinct species

Convergent - two unrelated species develop similar traits because they live in similar environments

Describe 2 molecular ways that evolutionary relationships are shown

Similarity in DNA, similar primary sequences in proteins