What are the 5 main evidences of Evolution?
1. Homologous Structures
2. Fossils
3. Embryos
4. Comparable DNA Structure
5. Vestigial Organs
What is Evolution?
The gradual change in a species over time
What is natural selection?
individuals that are better adapted to their environment and are therefore more likely to survive and reproduce
What are the 4 steps of Natural Selection?
1. Overproduction
2. Genetic Variation
3. Competition
4. Survival and Reproduction
What is adaption?
a trait that helps an organism survive and reproduce in its environment
What were Lamarck's views on Evolution/ how it worked?
His views were incorrect, he thought that if an organism needed a trait that it could acquire it
What were Darwin's view on Evolution?
That the organisms already had the trait needed to survive, the ones that did not, did not pass on the trait
What ship did Charles take and to where?
HMS Beagle to the Galapagos Island
What did Charles Darwin observe on the the island he voyaged to ?
the diversity of organisms, the remains of ancient organisms, and the characteristics of organisms
When faced with a change in an environmental condition, a population of a species can...... (get
M.A.D.
)
M
igrate-move to a more favorable location
A
dapt-they have to adapt if they don't migrate
If they do neither of these they
D
ie
What are Homologous Structures?
The similar structure of bone in various animals
What is Analogous Structure?
Look similar on the outside and have the same function, but have different structure/ development and the organisms have no evolutionary relationship
What is the significance of homologous structures in reference to Fossils.
Scientists can use homologous structures to put together new Fossils.
What is the difference between relative and radioactive dating/ which is more precise?
relative: dating fossils by layers of rock
radioactive: measuring amount of elements in fossil
-radioactive is more precise
How do Embryos help to prove Evolution?
because of similarities in early development
How does comparable DNA structure help to prove Evolution?
because of the theory that we all came from a similar ancestor and helps to prove while having comparable DNA
What are Vestigial Organs?
structures on modern organisms that have no (or very little) function
Diversity of Species:
Over time, different environment and genetic variation have produced, through natural selection, the variety of organisms that exist today
Why is there genetic variation in a species?
Meiosis and mutations
What is coevolution?
two species evolve together in response to changes in each other over time
What is Gradualism/ Punctuated Equilibrium?
Gradualism: slow and steady evolution over a long amount of time
Punctuated Equilibrium: Periods of short, rapid change followed by long periods of no change
What is Genetic Drift and what are it's 2 effects?
:gene frequencies of a population change BY CHANCE
-founder effect: colonization of new area
- bottleneck effect: natural disaster or human action
When does a population become a new species?
Speciation
What is a species?
a group of similar organisms that can breed and produce fertile offspring
What is reproductive isolation and what are the 3 divisions of it?
:species do not interbreed anymore, thus forming species
-Geographical: separated by land or water
-Behavioral: different calls or dances etc.
-Temporal: breed in different seasons
What is Divergent Evolution?
two groups of the same species evolve into different species?
What is Convergent Evolution?
Two different species evolve over time to look very similar (analogous structures) even though they were never once joined as a species
What is Directional Selection?
natural selection that results in a change among the traits of a population in one direction.
What is Disruptive Selection?
natural selection that results in a change among the traits of a population in two directions; could lead to two new population.
What is Stabilizing Selection?
natural selection that favors the average individuals