Biodiversity

Biodiversity - measure of number of species in a given area (specie richness), also refers to number of organisms within each species 

Varies across planet, partly due to environement, amount of energy flow 

Why biodiversity can change 

Succession - change in composition of a community over time, community of organisms cahnges its habitat - makes more suitable for other species, increases animal biodiversity, reduces plant 

Natural selection - variation exists within population - genetic mutations in common ancestors, more offspring produces than can be sustained (overproduction), adult numbers stay same, some individuals better adapted (beneficial allele) to environment than those without = competitive advantage, organisms reproduce + pass on beneficial allele to next generation 

Biodiversity and fossil record -  FR and biochemical analysis used to work out evoltionary relationships, often many species go extinct at same time = mass extinction, produces genetic bottleneck in biodiversity, followed by rapid diversification - species adapt to fill niches, diversification of species from common ancestor into several forms = adaptive radiation (e.g. Darwin's Finches)

Adaptations - change in a species, as a useful characteristic becomes more common, useful characteristic = adaptive trait, every aspect of organism subject to this - through natural selection - to its environment

Behavioural traits - actions bu organisms within a species which help them survive/reproduce, e.g. agoutis bury brazil nuts as a food store, many plants flower in spring as pollinating insects emerge

Physiological adpatations - internal processes within organism…