Evolution
What are all the non-random mechanisms of evolution?
what is Natural selection is the only non-random
What types of evolutionary processes will always increase genetic variation
Selection by divergence, gene flow, and mutations.
In two different rivers contain identical looking blue fish. These fish are known to have an extremally distant ancestor and cannot breed with each other. Would these fish be considered the same species with any of our concepts.
Yes, under the morphological species concept.
What mechanism of evolution when stopped between 2 populations contributes most to speciation
Gene flow
Can you think of an example where natural selection does not increase fitness?
No natural selection will always increase fitness.
Does the environment cause specific mutations to arise that help the organism survive and reproduce.
No mutations are a random process that is always happening.
In a squirrel population during the summer bigger squirrels are able to compete for food while smaller squirrels are chased off by the bigger squirrels. What is happening in this population and what is the impact on GV?
Directional selection and likely decrease.
A group of birds is found on two different islands. They look nearly identical but have distinct genetic differences and unique evolutionary histories. Under which species concept would they be considered separate species?
Phylogenetic species concept
In a species of frog one species may breed in early spring, while the other breeds later in the summer. What type of mechanism leads to isolation between these popuations.
Prezygotic
Would allopatric speciation always cause two population to form into different species.
Not always there are many populations that are living in allopatric and are still the same species. It depends on chance, how close the environment is and time.
If blue trout always mate with other blue trout and red trout only mate with other red trout what principle of hardy-Weinburg is this violating? Will this cause evolution?
What is random mating and no only the genotype frequencies changes
In the same squirrel population, a few cats move into the forest where the squirrels live. The smaller squirrels are too fast for the cats to catch, while the larger squirrels can defend themselves. What type of selection will occur in this population, and how will it impact genetic variation?
Disruptive and more genetic variation.
In a newly discovered group of mice there are two colors of mice white and brown who regular interbreed. Under what concept are these the same species?
What is the biological species concept
What type of reproductive barrier occurs when two species mate and produce offspring, but the offspring have lower survival rates or developmental issues, such as in some hybrids between closely related species?
Postzygotic
What could be a disadvantage of the phylogenetic species concept
It can cause us to classify way more species then makes sense.
A storm washes some trout form the Tennessee River into the copperhead river. The trout find another group of trout in the copperhead river that they live and mate with. What is happening to the copperhead trout and what is the impact on genetic variation.
What is gene flow and increase GV in copperhead trout
In a squirrel population the small squirrels do not have enough body heat to survive the winter, and the bigger squirrels cannot find enough food to survive the winter. What will happen in this population and what will the effect on genetic variation be
what is stabilizing selection and decrease GV
Two fossilized organisms are discovered, and scientists classify them as separate species based on differences in their skeletal structures. Under which species concept are they considered separate species?
Morphological species concept
How can genetic drift via founders' effect led to a new species to formation? What type of speciation would this be
We would see Allopatric by dispersal. The founder population will adapt to their new environment. A decrease in gene flow and different selection, mutations, and genetic drift can lead to the formation of a new species.
If you have a two fossils, what mechanism can you use to see if they are different species and why?
Morphological
A storm washes a group of trout from the copperhead river into a pond that previously had no trout in it. What will most likely happen to the alleles of this population and why.
What is fixation by genetic drift via founders effect
A group of blue fish had the evolved to have high fitness in a river as they can blend into the rocks. A group of red fish gets washed into their river and begins breeding with the blue fish. What mechanism is this and what is happening with GV and fitness.
Gene flow, Gv increase, fitness decrease
Two groups of white mice regularly interbreed and share extensive common ancestry while living on a small island. Under which species concept would they be classified as the same species?
Biological morphological and phylogenetic
A formation of a river splits a frog population into two. If enough time has passed, what would we most likely see between the two populations.
Allopatric speciation via vicariance
In a squirrel population, body size was inherited. The smaller, swifter squirrels easily outran predators like cats, while the larger ones were unfortunately eaten more often. Name Darwin's postulates and how they relate to this example.
Variation- Some are big while some are small
Heritability- The trait body size is heritable
Variable- Some survive and reproduce while others do not
Fitness- Those who survive and reproduce have larger bodies