Biodiversity
- Created by: charlottepicton
- Created on: 13-03-17 09:01
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…
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