LEC141 Revision

What did Darwin write

On the origins of species by means of natural selection (1859)

What can evolution explain

The wide variation of species and diversity

Who did darwin co-write with

Alfred Russel Wallace

Key concepts

heritable varitation, competition, selection, adaptation

What is competition for

Resources: food, space, mates

What is selection

Individuals live or die depending on the presence of a trait

Previous Scientists

Linnaeus, Lyyell, Malthus

What does selection act on

Individuals.

What is the modern view for evolution

Darwinian, but now with a mechanism for inheritance

What are the ratites

The large birds, rheas, tinamous, ostritch, emu, cassowary, kiwi

What remains in fossilisation

Hard parts of organisms

When did cyanobacteria evolve

3\.5 billion years ago

What did photosynthetic algae do

created the ozone layer

When was there an explosion in eukaryotic diversity

Early cambrian, 570 million years ago

When was ‘lucy’ alive

3\.2mya

Lucy’s qualities

Human like teeth, with ape like head

Modes of selection

Stabilizing, directional, diversifying

Allopatry

Species evolve from being isolated from each other (eg via continental drift)

Sympatry

Species evolve together

Exploitation types

predation, parasitism

Costs of reproduction

Mating effort, parental effort

Mating effort includes

Territory defence, mate attraction, female defence

Parental effort includes

investment in gametes, parental care

intra-sexual selection

competition for mates between individuals of the same sex

Inter-sexual selction

mate choice

Indirect sexual benefits

Males provide genetic benefits

Frog croaking

Females become more choosy based on croaking sound when they are from hybrid areas

Satte