natural selection

how has biodiversity arisen

natural selection

what are the steps of natural selection

1. mutations cause inheritable variation in a species

2. organisms overproduce offspring leading to infraspecific competition

3. some variation offers a selective advantage so they are better fitted to survive a selection pressure (something that causes death like predation, disease or climate)

4. individuals w selective advantage survive and reproduce, alleles passed to offspring

5. allele frequencies of favourable variation increase over generations

what is adaptation

through natural selection organisms with selective advantages become adapted to particular environments

what forms can adaptations take

anatomical - structures of an organism

physiological - functions of the structures of an organism

behavioural

anatomical adaptations of fennec fox

small

large ears so higher SA:V for increased heat loss

long snout to bring air temp down before it reaches lungs

fur colour that provides camouflage

physiological adaptations of fennec fox

kidneys with long loops of henle so less water is lost

faster breathing when temperatures are high

fennec fox behavioural adaptations

are crepuscular (active at dawn and dusk) as this is when temps are lower

dig dens to shelter during day