Natural selection Unit test Flashcards
What is evolution?
The slow, gradual change in the genetic material of a population of organisms over time
What is natural selection? Provide an example
he process by which evolution can take place, organisms that are best adapted/suited to the environment tend to survive and reproduce. “survival of the fittest”;
What is a population?
all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding
OR
A group of organisms of the same species that can interbreed and is the smallest unit in which evolution can occur.
What conditions are necessary for natural selection to occur? Give a brief description and example of each. Choose an animal species for your example.
a)- Inheritable Genetic Variation within the population
b)-Overproduction of offspring to ensure at least one survives
c)-Adaptive advantage (reproductive advantage)
d)-Competition for limited resources or selective pressure
What is fitness?
the ability to survive to reproductive age, find a mate and produce offspring
OR
The measure of a trait relative to the contributions to the following generation
Explain how populations of organisms can change over a period of time?
1)-They can evolve and adapt to different habitats and resources over many generations
When an organism has a trait that begins to dominate the population
2)-Predator population increase or decrease
3)- Environmental factors can increase or decrease resources
4)-Availability of shelter, mates, food, disease, environmental changes, etc.
Why did the average beak size of Galapagos ground finches increase over time?
Drought caused the seeds that were bigger to be able to survive, therefore the birds with the beaks that could consume those seeds were able to survive
When the drought occurred the smaller seeds were not available or harder to find.
Is animal behavior affected by natural selection? Give examples of pros and cons?
Yes, we can see this in sneaky crickets. Singing in crickets attracts a mate, but it also attracts predators. Some crickets did not sing and took advantage of those that did.
How does such diversity of life manage to exist in an area while using the same resources? Provide an example.
Niche Partitioning - think of the Wildebeest, zebra, gazelle share grasses at different times.
The way they use their resources doesn’t harm the ability of other organisms to use the same resources in the ecosystem. This allows more organisms to survive and coexist
What are the causes of historical mass extinctions? Based on natural selection, why do so many organisms go extinct?
-Quick environmental changes
-Such a large change and not the adaptations in population to be successful in new environment
-Not enough generations for the population to shift traits
What is speciation? What is the difference between Allopatric/Sympatric speciation?
Speciation is the process of species changing into new ones or splitting into new species
Reproductive isolation is key to the biological species concept.
Allopatric - physical barrier separating two populations and no longer breed
Sympatric - reproductive barrier arises and two populations no longer breed.
Describe different types of evidence for evolution.
F- fossil-remains of ancient orgainsm
A- Anotomy- body parts
M-moleculer-DNA ATP
E-embyrological-embryos look simular?
What is a vestigial structure and how does it provide evidence for evolution. Provide an example.
Is a structure that is left over and once was useful in an ancestor species.
How can you tell when two different species have a closely related common ancestor or a distant common ancestor?
Look at the similarities in fossils, DNA, anatomy. The more similar they are the more recent the ancestor was.
