Natural Selection and Speciation
What is the definition of a species?
A group that can interbreed and produce fertile offspring.
Does evolution happen quickly or slowly over many generations?
Slowly
An organisms ability to pass on its genetic material to its offspring.
Fitness
What is Mrs. Flannery's favorite vestigial structure?
Whale pelvis
A long thicker coat that protects from the cold in the winter and sheds out in the summer on horses that live in mountainous regions would be considered a what?
An adaptation.
What is a species goal?
Survive long enough to reproduce and pass on your genes.
Why would a species not evolve or change?
Their environment remains stable
The movement of genes into or out of a population.
Gene Flow
When looking at the development of a few different species scientists were able to identify that early stages of development showed the same stages. This led them to identifying an evolutionary relationship between the species. What type of evidence for evolution is this?
Embryology
A crocodile and a cat have the same forearm bone structure regardless of the fact that their forearms serve different functions. What does this indicate about the two species evolutionarily? What is the term for this?
They share common ancestry. Homologous structures.
What does it mean to be selected out of a population?
That the particular trait or characteristic will disappear from the population.
Why is genetic variation important?
It makes a species more able to adapt and survive in a changing environment.
The change in frequency of an existing gene variant in the population due to random chance.
Genetic Drift
Would a species with more or less amino acid differences be closer related to another species?
Less differences.
A beetle species that ranges from dark greenish brown to light green lives on leaves that are dark green. Over time lizards are able to pick off and eat the lighter green beetles more easily than the dark green beetles. Future generations of beetles have a higher percentage dark beetles. What is this an example of?
Natural Selection.
Is a species sees an elimination of the average phenotype and only exhibits the extreme phenotypes after a few generations what type of selection is this? Draw the graph that shows this with a dotted line for the original population.
Disruptive. Should have a dotted normal bell curve and then a new line with two peaks at the two extremes.
Founders affect.
The influence of closely associated species on each other in their evolution.
Coevolution
What is the newest form of evidence that has caused some previously perceived relationships to be reevaluated.
Molecular Biology/DNA evidence
A shark and a dolphin do not share a recent common ancestor and show very different internal structures for their fins despite them being used for the same purpose in the similar environments. What are their fins an example of?
Analogous structure
What are the two methods of natural selection?
Sexual Selection and Competition
Evolution is a result of four factors:
1. The potential for a species to increase in number.
2. The heritable genetic variation of individuals in a species due to mutation and sexual reproduction.
3.
4. The increase of those organisms that are better able to survive and reproduce.
What is the 3rd factor?
Competition for limited resources.
The process whereby distantly related organisms independently evolve similar traits to adapt to similar environmental demands.
Convergent Evolution
How do you know which fossil is the oldest? What is the term for this?
The deeper in the earth, the older the fossil. Super position.
A population of squirrels in a forest is divided when a river is rerouted through the forest. Over time these two populations were only able to breed with those on their side of the river and it eventually resulted in speciation of the two. What would be the term for this?
Geographic Isolation