Evolution
Evolution can only happen to
Populations of organisms over generations of time.
This is the broadest group of classification.
Domain
What is an index fossil?
A fossil that is commonly found and specific to a few periods of time.
A species that branched apart and gave rise to different species but is itself no longer alive today.
Common ancestors
What is reproductive isolation?
When something happens that causes portions of a population to stop reproducing with one another.
Ex. Geographic separation, differences in "mating season," differences in mating calls/behaviors, genetic incompatibility
What does “the fittest” mean in an evolutionary sense?
Able to survive and reproduce.
This is the most specific group of classification
Species
When looking at layers of rock with fossils in them, what does the rock layers position to one another tell us?
The closer the rock is to the surface the younger that rock layer likely is.
How do we use DNA to tell if a species is related?
The more similar two organisms DNA is the more related those two organisms are.
How is an ecomorph different from a species
Ecomorphs refer to the body type or an adaptation that an organism has, species refers to the ability to reproduce.
In the experimental islands off of Iron Cay, scientists put the same species on the island and over generations they saw that the lizards had changed their ecomorph.
This type of evolution happens when two different species are living in similar environments and develop similar traits.
Defines convergent evolution
At what classification level are fungi and plants no longer in the same category?
kingdom
What is a vestigial structure?
A structure that is still present in an organism but has little or no current. It's presence suggests that the organism once had this structures and is related to other organisms that still have the structures.
ex. hip bones in whales
What are phylogenetic trees based on?
DNA, anatomy, embryology, fossils. Suggest an evolutionary history.
Provides all of the possible allele types in a population, not necessarily what alleles are expressed.
Gene Pool
Two or more species evolve in response to changes in each other
Defines coevolution
At what classification level are starfish and cats no longer in the same category?
phylum
These structures, found in different species, are very similar to each other but are used in different ways. Ex. Whale fins compared to bat wings.
Homologous structures
What do cladograms show us?
They compare physical structures and suggest relatedness.
What does DKPCOFGS stand for?
The order of the classification system for life:
Domain, kingdom, phylum, class, order, family, genus, species
Closely related species evolve toward two different phenotypes
Divergent Evolution, caused by disruptive natural selection.
What are the different kingdoms of life?
Plants, animals, fungi, and protists.
These body parts are found in different species, they have the same purpose/function, but they are not the same structures.
ex. wings on a bat compared to wings on a fly
Analogous structures
A new species is formed when
When members of different populations can no longer mate successfully with one another, this happens as a result of reproductive isolation.
What is the benefit of genetic variation?
Creates a more durable population. There is a larger variety of genes that could survive a larger amount of circumstances.