Your environment selects the fittest organism for survival, which then passes it down
“Fight” for limited resources, where organisms need to improve to survive.
Those with more favorable phenotypes are more likely to survive/produce more offspring, thus passing on those traits.
Some individuals can live longer or shorter than others.
Variations in the environment can significantly alter the fitness of an organism
How much it reproduces.
New traits are because of RANDOM MUTATIONS:
Phenotypic differences, upon which natural selection can act.
Natural Selection affects INDIVIDUALS!!!
Evolution affects POPULATIONS!!!
Differences accumulate between two CLOSELY related species.
Leads to Speciation.
Variation in a structure/limb of the common ancestor.
Like all mammals have “arm-like” structures.
Different species have evolved in similar ways independently on their own.
Structures that share a similar function, but not (recent) common ancestry; non-homologous
A structure that was useful for our ancestors, but is USELESS now.
Our tail bones, we don’t have tails.
Whales have hip bones, but they don’t have hips.
New species are created from ISOLATED reproduction.
Allopatric Speciation (DIFFERENT):
Geographic isolation leads to speciation.
Sympatric Speciation (SAME):
Some individuals can’t reproduce together so they are isolated reproductively.
Evolution happens RAPIDLY because of a change in a static environment
The evolution that occurs of millions of years.
A huge event drastically changed a population, which was then changed into something very different, usually if a sub-population dies.
The population is DECREASED.
Diversity is DECREASED.
A certain sub-section of the population left the normal population to make their own “species” which varies from the OG population.
An organism moved into/out of another population which INCREASES the genetic diversity, which could change the population.
DOESN’T really happen in LARGE populations. ONLY small populations.
P = Probability/frequency of DOMINANT allele
Q = Probability/frequency of RECESSIVE allele
The above equations are only possible on populations where the following 5 conditions are met:
But populations like this just do not exist, which proves the evolution is real.
- NO Random Mutations AKA Non-evolving
- Large population size
- No gene flow (no immigration/emigration)
- Random Mating – No sexual selection
- NO Natural Selection