Evolution Test Review

List and describe Darwin’s 4 Principles of Evolution

Natural Selection Darwin’s theory of evolution 4 observable principles – Overproduction – Genetic variation – Adaptation (of a SPECIES) – Selection (based on greater reproductive success)

Describe evolution using a complete sentence

Describe evolution using a couple of complete sentences Organisms best suited to their environment will survive and reproduce in greater numbers. Over time, the species will begin to look more and more like those organisms best suited because their genes occur in a greater % in the population.

Whenever one organism leaves more successful offspring than another, in time its genes will dominate the population gene pool. Eventually, the genotype leaving fewer offspring must become extinct in a stable population. Ultimately, natural selection operates by different reproductive success among organisms of the same species.

Principle of evolution?

Principle of evolution Variation…same species, different phenotype due to genetic variation in traits

Principle of Evolution?

Principle of Evolution Overproduction..organisms produce more offspring than are likely to survive. This ensures that some will survive and the species continues into the next generation

Organism Trait: Giraffe Coat how many variations of this trait to do you see?

number of spots, shape of spots, shape of spots vary on one animal, color of spot, some spots multi-colored, background hair color, pattern of spots on the animal, border of spots, spacing between each spot….. Massive variation of one trait

What is the role of mutation in natural selection?

Mutations are a source of genetic variation. Mutation is NOT a principle of evolution.

What is speciation? Describe the process that leads to speciation.

Speciation is due to Geographic Isolation Eventually this leads …reproductive isolation This means new species have evolved. Even if You put these new organisms “back together” they will not reproduce with each other because they do not recognize each other as the same species.

Evidence of Evolution What are the types of evidence used to determine the evolutionary relationship between species?

1. Comparative Anatomy -homologous structures -analogous structures -vestigial structures 2. Embryological 3. Molecular (DNA) 4. Fossil

1. Comparative Anatomy -homologous structures divergent evolution common ancestor similar structure, different function -analogous structures convergent evolution evolved in same environment (~ pressures) similar function, different structure

Homologous or Analogous Elephant Leg

Homologous or Analogous? Elephant Leg and Bird wings are Homologous structures the underlying bone structure is very similar Butterfly and Bird wing are Analogous structures they have similar functions but a very different underlying structure. Elephant Leg

Homologous or Analogous? Elephant Leg and Bird wings are Homologous structures the underlying bone structure is very similar Butterfly and Bird wing are Analogous structures they have similar functions but a very different underlying structure. Elephant Leg

Homologous or Analogous

Homologous similar structure, different function Function ---flying Function-----grasping function----crawling along the ground

What evidence is represented here?

This is a vestigial structure… Is it considered a homologous or analogous structure?

This is a vestigial structure… Is it considered a homologous or analogous structure? Homologous..similar structure (limb), different function (none)

Which are most closely related? Evidence that supports your answer. KingdomAnimal PhylumChordata ClassAves Order PasseriformesPelecaniformesPasseriformes familyFringillidaeArdeidaeTurdidaeCorvidae GenusCardinalArdeaSialiaCorvusCyanocitta 12345

Organisms 4 and 5 Evidence: these two organisms have similarities through the family level of organization. KingdomAnimal PhylumChordata ClassAves Order PasseriformesPelecaniformesPasseriformesPassiformesPasseriformes familyFringillidaeArdeidaeTurdidaeCorvidae GenusCardinalArdeaSialiaCorvusCyanocitta CardinalHeronBlue BirdCrowBlue jay

Taxonomy: the branch of science that classifies organisms based on structural and microbiological similarities

What is the importance of genetic variation in the survival and reproduction of a species?

Genetic variation allows a species to change in response to changes in the environment. Without these variations, a species would face extinction if the environment changes and new adaptations are required. Example: rock pocket mice with pale fur and dark fur. The environment changed to a dark, lava substrate. If there were not variation in fur color, all pale fur mice would have been killed by predators. No survivors over time.

Which organisms share the trait of seeds?

Which organisms share the trait of seeds? Oak and Yew Difficulty solving this? Use the “snip” method. Imagine you have cut the Cladogram tree just below the trait hash mark. Every organism that would “fall off” below the cut does NOT have the trait, those that remain in the tree above the cut HAVE the trait.

Which organisms share the trait of seeds? Oak and Yew Difficulty solving this? Use the “snip” method. Imagine you have cut the Cladogram tree just below the trait hash mark. Every organism that would “fall off” below the cut does NOT have the trait, those that remain in the tree above the cut HAVE the trait. These two organisms are the only ones that remain in the Cladogram tree when it is cut below the “seeds” hash mark.

Which organisms share the trait of losing their leaves? (loss of leaves)

Which organisms share the trait of losing their leaves? (loss of leaves) Psilotum