Natural selection
What is natural selection?
process of best-fitted organisms surviving to reproduce
pass on genes to offspring leading to inherited traits
driving force between evolution
happening continuously over billions of years
What generates variation between organisms?
mutations
sexual reproduction
What are runts?
competition between offspring if many birthed at once
usually one individual is weaker (mutations/ allele combinations) and dies
Abiotic factors driving natural selection
temperature
water availability
mineral availability
natural disasters
CO2/ O2 levels
pollution
What type of factors are these?
density-independent (not affected by population size)
Natural selection 1
, What is intraspecific competition?
members of the same species competing for the same resources
What gives individuals better fitness?
suited to their niche because of their genotype combination (reproductive
potential)
bigger/ smarter/ faster/ stronger = more likely to survive and pass on genes
through reproduction
What type of traits are necessary for evolution and why?
heritable
NOT acquired characteristics
Biomes
Factors affecting coral reef ecosystem
water depth - light penetrating
pH - 8-8.5
salinity - 30-40ppm
clarity - light penetrating
temperature - 25-30
Adaptations of coral reef ecosystem
symbiotic relationship eg algae give energy
camouflage
protective covering
reproductive strategies eg asexual, eggs
For any given temperature and rainfall pattern…
an ecosystem will develop
What is a biome?
Natural selection 2
What is natural selection?
process of best-fitted organisms surviving to reproduce
pass on genes to offspring leading to inherited traits
driving force between evolution
happening continuously over billions of years
What generates variation between organisms?
mutations
sexual reproduction
What are runts?
competition between offspring if many birthed at once
usually one individual is weaker (mutations/ allele combinations) and dies
Abiotic factors driving natural selection
temperature
water availability
mineral availability
natural disasters
CO2/ O2 levels
pollution
What type of factors are these?
density-independent (not affected by population size)
Natural selection 1
, What is intraspecific competition?
members of the same species competing for the same resources
What gives individuals better fitness?
suited to their niche because of their genotype combination (reproductive
potential)
bigger/ smarter/ faster/ stronger = more likely to survive and pass on genes
through reproduction
What type of traits are necessary for evolution and why?
heritable
NOT acquired characteristics
Biomes
Factors affecting coral reef ecosystem
water depth - light penetrating
pH - 8-8.5
salinity - 30-40ppm
clarity - light penetrating
temperature - 25-30
Adaptations of coral reef ecosystem
symbiotic relationship eg algae give energy
camouflage
protective covering
reproductive strategies eg asexual, eggs
For any given temperature and rainfall pattern…
an ecosystem will develop
What is a biome?
Natural selection 2
