Your environment selects the fittest organism for survival, which then passes it down

Natural Selection:
RANDOM PROCESS!!!

Competition:
“Fight” for limited resources, where organisms need to improve to survive.
OR
Those with more favorable phenotypes are more likely to survive/produce more offspring, thus passing on those traits.

Differential Survival:
Some individuals can live longer or shorter than others.

Environments Change:
Variations in the environment can significantly alter the fitness of an organism

Evolutionary Fitness:
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!!!

Divergent Evolution:
Differences accumulate between two CLOSELY related species.
Leads to Speciation.

Homologous structures:
Variation in a structure/limb of the common ancestor.
Like all mammals have “arm-like” structures.

Convergent Evolution:
Different species have evolved in similar ways independently on their own.

Analogous Structures:
Structures that share a similar function, but not (recent) common ancestry; non-homologous

Vestigial Structures:
A structure that was useful for our ancestors, but is USELESS now.
LEFT-OVER features.
Example:
Our tail bones, we don’t have tails.
ALSO
Whales have hip bones, but they don’t have hips.

Speciation:
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.

Punctuate Equilibrium:
Evolution happens RAPIDLY because of a change in a static environment

Gradualism:
The evolution that occurs of millions of years.

Bottleneck Effect:
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.
AND
Diversity is DECREASED.

Founder Effect:
A certain sub-section of the population left the normal population to make their own “species” which varies from the OG population.

Migration:
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.

Hardy-Weinberg Equilibrium:
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.

  1. NO Random Mutations AKA Non-evolving
  2. Large population size
  3. No gene flow (no immigration/emigration)
  4. Random Mating – No sexual selection
  5. NO Natural Selection