The raw material on which natural selection acts to produce evolutionary change is caused by
Which idea is attributed to Malthus?
Populations tend to increase exponentially whereas food supplies do not
Fossil evidence shows that giraffes living 1000 years ago had much shorter necks than giraffes seen today. Which of the following statements best explains this observation?
The giraffes acquired longer necks through the continuing process of natural selection
Which of these conditions are always true of populations evolving due to natural selection?
The population must vary in traits that are heritable. Some heritable traits must increase reproductive success.
________ structures are those similar in different species because of their derivation from a common ancestor.
_________ structures are similar in different species due to convergent evolution, not common descent.
Analogous or Homoplastic
_____ structures are those that have no apparent function but resemble structures that ancestors had.
The "fittest" individuals are those that _______ to reproductive age successfully ____________, and have large numbers of surviving offspring.
Many crustaceans (eg lobsters, shrimp, crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of a ______.
Gill pouches in chick, human, and house-cat embryos are an example of ____________.
There is a population of beetles that typically have black wings... Recently some beetles born with white wings...shortly after laying their eggs the white beetles die and there are only adult black winged beetles during the late fall. What is true about the beetles?
White and black winged beetles have equal fitness.
Presume the following genetic data:
Base #: 123 456 789
ancestral pop: TTT CAT CCA
descendant pop 1: TTG CAT CCG
descendant pop 2: TTT CAA CCG
Which base numbers represent synamorphies?
3 and 6 (because the descendant is dif from the ancestral ... but in only ONE descendant pop not both)
Convergent evolution of two distantly related species is the result of
Natural selection for similar adaptations because of common environmental conditions
You have found a very interesting fossil and want to determine how old it is. Measuring radioactive darwinonium you find that 1/8 the original parent isotope is present in the sample. The half life of darwinonium is 100 myo. How old is your fossil?
300 million years old.
One year = 1/2 left, Two year = 1/4 left, Three year = 1/8 left. So three years * 100 myo = 300 myo.
Old world vultures closely resemble new world vultures. However, old world vultures are related to eagles and hawks, while new world vultures are more related to storks. This is an example of
In Lake Victoria, over 300 species of cichlid fish have evolved to utilize different resources in the lake. Dramatic changes in the water level of the lake resulted in periodic isolation and reintroduction of local populations contributed to the evolution of many of these related species from a common ancestor. This is an example of:
The time in the history of Earth when evolution was progressing at the most rapid rate is the:
When did the appearance of dinosaurs occur?
Either Paleozoic or Mesozoic Era (within the Phanerozoic Eon)
When did two mass extinction events occur?
1. Two in Paleozoic (Ordovician and Devonian)
2. One end Permian (bn Paleozoic and Mesozoic Eras)
3. Triassic extinction in Mesozoic
4. Cretaceous extinction bn Mesozoic and Cenozoic
When did the Cretaceous extinction occur?
Between Mesozoic Era and Cenozoic Era, during the Phanerozoic Eon.
In the Devonian, Pennsylvania was located in what hemisphere?
Southern (with a rain forest atmosphere)
"There is no goal to evolution" means what?
Evolution does not have a goal, it does not try to progress the way it has, it was not trying to become more complex or make limbs etc. It is a series of experiments.
The tetrapods that ventured onto land and found a new world filled with opportunity.... this ecological opportunity combined with the morphological innovation of limbs, lead to _____ on land.
a bat wing bone and a cat paw bone, a whale flipper bone, and a human arm bone... are all examples of what?
Scientists studying evolution on the Solomon Islands described which animal as the "poster child" for the biological species concept?
What can you infer about speciation- the process by which one species splits into 2 or more species- based on the ABC news video about the Solomon islands?
Physical separation of populations is often part of the speciation process.
Why did the biologists consider a frog they found to be a new species (on the Solomon Islands)?
Its call was unique.
When Darwin wrote On the Origin of Species, he knew very little about the subject of _____, an essential component of evolutionary theory today.
What is true about a new mutation within a population?
Once it is established in a population, a new mutation may increase or decrease in frequency depending on the environment.
You are infected with an antibiotic-resistant strain of Klebsiella pneumonia. Where did you most likely contract it?
What is true about current research in regards to medians and islands when comparing the diversity of animals or plants?
Current research indicates medians are NOT similar to islands when comparing the diversity of animals or plants.
You discover that a company illegal dumped old vats of PCBs into a nearby river. What do you expect to see?
Fish with deformities.
What does it mean to say a plant or weed (pigweed ex) is resistant to herbicide?
If a plant or weed is resistant to herbicide, it thrives despite the application of herbicides intended to kill them.
In the past, herbicides were very effective as a pigweed killer, but today _____.
Pigweed is taking over fields of cotton and soybeans.
The scientists who produced the herbicide warned against over use, saying over time ___.
Crops would start to be affected by the herbicide.
Why is pigweed so difficult to control?
The number of seeds it produces, number of inches it grows daily, and its thick, woody stem.
What effect(s) has the proliferation of herbicide-resistant pigweed had on southern farmers?
They may have to pick crops by hand, large machinery is prone to damage, and they have to hire laborers to cut and remove weeds by hand.
How did the drought in the Galapagos Islands lead to an increase in beak size in the medium ground finch population?
Grants say before drought the finch pop fed primarily on small easy seeds and tougher seeds were available but not usually eaten. During the drought only a limited number of small seeds were produced leaving mostly larger tougher seeds which then made finches unable to eat larger seeds die of starvation.
The Grants study beak size in the Galapagos Islands reached their conclusions based in the information that was true that...
Birds that could eat larger, tougher seeds survived and reproduced through the drought. Beak size varies among the birds in the finch population under study. Beak size is an inherited trait in the finch population under study.
Darwin suggested that evolution by natural selection requires what?
1. A trait must be heritable so that alleles that encode a favorable trait can be passed to offspring.
2. A trait must exhibit variation within the population.
3. For any given environmental condition, certain heritable traits make it more likely that some individuals will survive and reproduce than others.
Evolution by natural selection DOES NOT occur because _______.
existing individuals acquire new characteristics in response to an environmental change.
Environmental changes do not induce _____ in a population. Rather, the population already exhibits a range of _____ for any given trait that ______ can act on.
Mutations, Variations, Natural Selection
Describe how you would select the most parsimonious tree for a species.
Whatever tree requires the fewest base-change events would be the most parsimonious phylogenetic tree.
Feathers either play a role, or may have played a role, in what?
Extended hops, Courtship, Gliding, Flight
____ is the rapid speciation under conditions in which there is little competition.
The different finch species found on the Galapagos Islands probably arose as a result of what?
What main events happened during the Archaean Eon?
The origin of Earth, and the oldest fossils of cells (prokaryotes) appeared.
What main events happened during the Paleozoic Era?
The Cambrian Explosion, and the first tetrapods and insects appeared.
What main events happened during the Mesozoic Era?
The origin of mammals, and Dinosaurs evolved and radiated.
What main events happened during the Cenozoic Era?
Humans appear, and Major Radiation of Pollinating Insects.
What are the best ways a fossil will form?
1.If there is an organism with a hard shell or boney skeleton
2. If the organism lives where sediment is being deposited such as by a river or ocean
3. If there is a large population and long existence
4. The organism lives and dies in an environment with a low oxygen content (because low oxygen content inhibits decomposition)
What is true about adaptive radiation?
Adaptive radiation occurs when a single lineage produces many descendant species.
What is an organism that is an example of an adaptive radiation? What is not?
Horses and deer post-dinosaur, anolis lizards of the carribean, honey creeper song birds of the Hawaiin islands... ALL ARE.
Mammals and reptiles in the post dinosaur age are NOT examples of adaptive radiation, as they are not descended from a single lineage.
T/F? Convergent evolution is said to have occurred if the mouse species on two islands with similar habitats are found to have similar characteristics even though they originate from different species.
What is convergent evolution?
When selective pressures produced by similar conditions (like habitat) favor the evolution of similar solutions.
Which anolis lizard ecomorph has long legs?
Trunk/ground. These ecomorphs need long legs to jump from one broad perch to another.
Which is true about the evolution of Anolis lizards in the Caribbean Islands?
The phylogeny of ecomorphs on a given island reveals that adaptive radiation has taken place.
What was the main selective pressure behind the evolution of different Anolis lizard species in the Caribbean?
Specific ecological niches.
Different species evolved in response to selective pressures created by specific ecological niches on the islands.
T/F? The evolution of different ecomorphs on the Caribbean Islands is an example of stabilizing selection.
Evolution of different ecomorphs is an example of disruptive selection. Each new ecomorph had characteristics that were ideal for a particular habitat, but these ch developed, then the lizards lost the ability to survive effectively in the other habitats on the island.
How can mass extinction events be distinguished from background extinctions?
A mass extinction occurs when at least 60% of species are wiped out within 1 million years.
What percent of a species must be wiped out within 1 million years to describe a mass extinction?
at least 60 % a species
How do fauna documented in the Doushantuo, Ediacaran, and Burgess Shale fossils compare?
Burgess Shale fauna are the largest and most morphologically complex. They are the youngest fossils documenting the Cambrian explosion and contain virtually every major animal lineage.
Which likely trigger of the adaptive radiation known as the Cambrian Explosion is the best example of ecological opportunity?
Increased oxygen levels in the atmosphere. Bc higher oxygen levels represent the availability of new or novel resources only, this is the best example of ecological opportunity.
What is strong evidence supporting the impact hypothesis for the extinction of dinosaurs?
Extremely high quantities of iridium in rocks that formed around 65 million years ago.
This presence of an element abundant only in asteroids and meteorites proves an asteroid impact occurred at the K-P boundary, around the time dinos went extinct.
What happens during anaphase?
Sister chromatids separate and daughter chromosomes migrate to opposite poles.
During ______ centromeres come apart, and sister chromatids become full-fledged chromosomes, which migrate to opposite poles of the cell.
During prophase a homologous pair of chromosomes consists of ________.
2 chromosomes and 4 chromatids
Which event does NOT take place before the start of mitosis?
The nuclear envelope disintegrates. (this happens after mitosis begins)
What events take place before mitosis begins?
The parent cell grows, DNA is replicated, organelles proliferate
Mitosis takes place during _____, but _____ is the ____ phase of the cell cycle.
M phase, M phase, Shortest
cell division in which the nucleus divides into nuclei containing the same number of chromosomes
Two recently replicated DNA strands that are joined together just before cell division.
What stage of mitosis is characterized by the disintegration of mitotic spindles and the formation of two new nuclear membranes?