Day 2 Evolution
We cannot begin to talk about animals without a solid understanding of evolution. This class will explore zoology through the lens of evolutionary structures and traits.
EVOLUTION!
The biggest arguments about evolution come about because people do not understand the definitions
-Evolution- Change over time
-Trait- A characteristic that is inheritable
-Adaptation- A mutation or trait that is beneficial
-Speciation- When one species changes enough to become two different species
-Microevolution- The change of gene frequency in a population
-Macroevolution- That all organisms evolved from a common ancestor
-The history of life/ Single cell hypothesis- All life evolved from a single cell
-The word evolution means change over time.
-We can apply this to anything. We can say that a band or musician's career has evolved. This does not mean that it got better it just means that it has changed over time.
The biological definition of evolution is - change of allele frequency over time.
-EVERYTHING CHANGES
-In biology, evolution means change of allele frequencies over time. Think of this as a change in genes over time
In order to pass on your genes you need to reproduce. Evolution is all about who reproduces
-The four mechanisms of evolution refer to who chooses who gets to reproduce
Watch this video on evolution. Create a box in your sketchbook, title it "Evolution" and take notes, write down the definitions and explanations in your own words and include an image in your sketchbook.
The four mechanisms of evolution
Natural Selection
-Is when nature chooses who gets to reproduce
-Survival of the fittest
Artificial Selection
-Humans choose who gets to reproduce
-How we turned wolves into Chihuahuas
Sexual Selection
-The opposite sex chooses who gets to reproduce
-Usually goes against natural selection
-A peacock's feathers and a frog's croak are good examples
Genetic Drift
-This is the only one that is not a selection
-It is usually an accident
-You reproduce with what you have because they are the only options
-The only ones in an area (Founder Effect) or a disaster kills off most of the group (Bottle Neck effect)
-Speciation is when one species turns into another species.
-Speciation uses evolution to describe its process but it is separate from evolution
-History of life
-The first cell hypothesis is the hypothesis that one cell turned into all life on earth. This is a hypothesis that uses evolution to describe how it happened but is not evolution.
Watch this short video on evolutionary structures. Create a box in your sketchbook, title it "Evolutionary Structures" and take notes, write down the definitions and explanations in your own words and include an image in your sketchbook.
Homologous Structures
Analogous Structures
Vestigial Structures
