A species of freshwater snail is introduced to many ponds on an island. In ponds with crayfish (a snail predator), the snails evolved a larger and more globular shell than in ponds without crayfish. In an experiment, a grad student puts together snails from both types of ponds and carefully records their mating attempts. She finds that the difference in shell size and shape prevents most mating attempts between snails from the two kinds of ponds. Which statement summarizes what is happening in this example?   Question 13 options:   In allopatry, mechanical isolation evolved as a by-product of natural selection   In allopatry, natural selection caused the evolution of post-zygotic barriers   In sympatry, behavioural isolation evolved through gene flow   In sympatry, behavioural isolation evolved through genetic drift

You find an old data set from a hibernation study. Unfortunately, the only information is what is listed in the table below:    a) Based upon the data presented, what type of organism is this data set likely to have been based on?  Describe it using the vocabulary that we learned in class. b) What might the species be? c) Graph the body temperature data provided in the table AND also graph what the body temperature data might look like for a small hibernating mammal.  You do not have to include a full figure caption but do need to include a legend, if applicable.

In a population of birds, males have long red tail feathers that they use in mating displays, and also sing in the mornings to attract females. You find that some males have more red feathers in their tails than others, while some sing for longer periods of time. In this bird species, a high proportion of eggs fail to hatch. You measure the number of eggs that successfully hatch that are fathered by each male bird, and find that the number of successful hatchlings is proportional to how long a male sings, but is unrelated to the amount of red in his tail. Question: Propose an explanation for why males evolved both to sing and to have red tails, and how females likely evolved in response to both traits. [Note:  avoid writing a paragraph for each sentence prompt; this should still be short, concise answers and Please write four sentences guided by the individual prompts] Your answer:   Sentence 1: State which males and which females had the highest fitness.   Sentence 2: What feature…

You are examining a population of C. elegans in their natural habitat, a fresh steaming pile of nutrient-rich compost.  Predict what you might expect to see in terms of mode of reproduction in the population.    a. The population will primarily reproduce asexually then when they run out of nutrient-rich compost.    b. The population will have mostly hermaphrodites with a few males.   c. The population will have a really high frequency of males compared to lab conditions.   d. The population will primarily undergo sexual reproduction.

Red-eyed tree frog eggs can hatch up to two days earlier than average when they detect vibrations. However, if they hatch more than two days earlier than expected due to vibrations, the embryos are typically not developed enough to survive outside of the egg. Explain how natural selection inhibited frog eggs from hatching any earlier than two days before expected hatching. Explain your answer in 1–2 sentences.

The phylum Chordata only contains vertebrate species.   Question 4 options:   True   False The development of amniote eggs allowed animals to move away from water.   Question 1 options:   True   False

Because many of the key mechanisms of evolution activate when sperm and egg combine, volutionary change happens faster for organisms with short life cycles (viruses, bacteria, fruit fly, yeast) compared to organisms with long life cycles (humans, elephants, tortoises). True False

Mules are hybrids of donkeys and horses, and they are sterile. Which term correctly describes this reproductive isolating mechanism between donkeys and horses? Mechanical Postzygotice Prezygotic Temporal Behaviora

Scientists found that different beak shapes correlate with different mating songs in Darwin's finches. Which hypothesis does this support?   A. Darwin's finches are not different species according to the Biological Species Concept.   B. Adaptation to different food sources led to behavioral isolation in Darwin's finches.   C. Adaptation to different food sources likely occurred after reproductive isolation in Darwin's finches.   D. Mating songs are primarily determined by the acoustics of different beaks.

Scientists have also noticed unusual coloration among certain condor populations. Andean condors are typically black in color.  However, a few unique white feathered individuals have occasionally been noted. These white feathered individuals are not well-camouflaged, and are easily spotted by larger predators.  Recently, scientists noted that a black feathered condor had mated with a white-feathered condor, and their three chicks all appeared to have gray feathers. Closer examination of these condor chicks revealed that the chicks actually possessed a mixture of black feathers and white feathers, giving them a gray appearance from a distance. Please NAME and EXPLAIN the genetic phenomenon described here.