EVOLUTION Flashcards
Define micro-evolution and provide an example
- Describes the small scale changes within gene pools over generations
Eg.) The evolution of the B&W pepper moth during the industrial revolution
Why were the Galapagos islands of particular interest to Darwin?
- They were volcanic islands that were relatively young and easy to study
- They contained few species but high variation within populations of species
- Species varied from island to island
- Few people had documented scientific findings from the Galapagos
What mechanisms led to the speciation of Tiktaalik?
- Competition
- Variation
- Natural selection
What evidence supports the fact that tetrapods and fish are closely related?
- The embryos of modern fish and tetrapods look similar
- Both modern fish and tetrapods are vertebrates
- The DNA of modern fish and tetrapods are similar
In the fall, monarch butterflies will migrate to warmer climates in order to survive. This is an example of:
Behavioural adaptation
In the spring, the city of Winnipeg fogs to kill off mosquitoes. Most of these mosquitoes die but few pesticide resistant mosquitoes remain. The next year there is an increase on the number of pesticide resistant mosquitoes. This is an example of:
Physiological adaptation
Over millions of years, the blowhole of the whale has moved from the tip of its nose to the top of its head. This is an example of:
Structural adaptation
What type of adaptation does an arctic fox use to avoid predation?
camouflage
The male birds of paradise will do a fancy dance to attract a mate. What type of adaptation is this?
Behavioural
A strain of pneumonia is showing antibiotic resistance and is becoming more common each year. This is an example of:
- Physiological adaptation
- Directional stabilization
Tiktaalik evolved from an aquatic species to a land dwelling species. This is an example of:
- Divergent evolution
- Adaptive radiation
- Natural selection
Baby birth rate has remained between 6-8 pounds for hundreds of years. This is an example of:
Stabilizing selection
What best explains the evolution of a long colourful tail in peacocks?
The founder effect
The finches of the Galapagos islands have evolved over thousands of years to have different beaks specialized to collect specific foods in their environments. This is an example of:
- Divergent evolution
- Adaptive radiation
- Speciation
Divergent evolution
Is the process in which an ancestral species gives rise to new species that are adapted to different environmental conditions.
The migration of butterflies, birds and caribou is an example of:
Behavioural adaptation
The elephant hawk moth will look and behave like a snake in its larval stage to avoid predation. This is an example of:
- Behavioural adaptation
- Structural adaptation
Stabilizing selection
Favours individuals with common phenotypes, and selects against those with extreme phenotypes
A population of sea stars are found in a range of sizes, from small(8cm) to large(16cm). Over time however, the average size of the population shifts so most sea stars in the population measure 12 cm across. This is an example of:
Stabilizing selection
Directional selection
Favours those with rare phenotypes and selects against those with common phenotypes
Artificial selection
Is when humans select specific organisms to breed to produce offspring with desired traits
Disruptive/diversifying selection
Favours those with extreme phenotypes and selects against the average
A population of flowers in a meadow show multiple colours of petals from pale pink to shades of darker pinks to a very dark Burgundy. Overtime, the population shifts and only very pale pink and very dark Burgundy petals are seen. This is an example of?
Disruptive selection
A population of scorpions is known for its toxic sting and its medium to large pincers. Overtime the population is made up of only scorpions with very large pincers. This is an example of:
Directional selection
What provides evidence that supports the theory of evolution?
- Palaeontology
- embryology
- Comparative anatomy
- Molecular genetics
Which 2 bones are found in parallel the forelimb of a frog, rat and human?
- Radius
- Ulna
Marine organisms known as limpets have shell colors that range from white to dark brown. The extreme variations in colour ( white and dark brown) are selected for since they blend into the surrounding environment. Over time these limpets evolve to be two distinct species. This is an example of:
- Disruptive selection
- Divergent selection
Describe the process of discovery that led Darwin to formulate his theory of evolution by natural selection.
- Darwin found fossils of Glyptodonts and noticed they resembled the prospect day South American armadillo and questioned if they could’ve evolved from the ancient Glyptodont.
- On the Galapagos islands, he collected 13 different finches and concluded that each species could adapt/specialize to fit into its own island environment.
- Darwin concluded that variations of different species uniquely adapt/specialize to their own island environments.
Homologous structures
Is when they have evolved from the same species but have different structures or functions
Analogous structures
Is when they have the same structural functions
Evolution
Refers to the permanent genetic changes within a population that occurs over successive generations.
* Populations evolve, not individuals
Gene pool
All the DNA in a population
Macro-evolution
Refers to the large changes in form as viewed on fossil record, involving whole groups of species
Palaeontology
The dating of fossils which gives us some of the most direct evidence of evolution
Comparative Anatomy
The study of the morphology of different species which show similarities between bone structure and function
Biogeography
The study of geographic distributions that can indicate where species may have originally arisen
Embryology
The study of embryonic development in different organisms that show trends of development in different species
Biochemistry
The similarities/differences in the biochemical makeup of organisms can closely parallel the similarities/differences in appearance
Molecular Genetics
Sequencing of DNA and proteins indicates the degree of relatedness between organisms
Variation
Each individual differs from all other members of its species, and some differ more than others. Evolution selects organisms that are best suited to their environment at the time. Therefore, variation allows adaptation
Adaptation
Allows organisms to become better suited to their environments
Genetic drift
Is a random increase/decrease in alleles often resulting from a small population.
- The founder effect
- The bottleneck effect
Bottleneck Effect
Occurs when a population experiences a dramatic decrease in population often due to weather events, human impact, disease or predation.
Eg. Pingelap
Sexual selection
Involves competition between males more mates and the choices females make for mates. Males and females usually look quite different - this is called sexual dimorphism
Eg.) Antlers- males use combat or visual displays- feathers
The Founder Effect
Occurs when the allele frequencies in a group of migrating individuals are, by chance, not the same as that of their population of origin. This occurs more frequently on islands cause of the small population.
Gene Flow
Is the movement of alleles from one population to another through migration.
Eg.) Zebra mussels moving to lakes
Mutations
Introduce new alleles and variation into a population. The more genetic variation, the greater chance of a selective advantage in a changing environment.
Is evolution a theory or a law?
By definition, evolution is a theory because there are tons of embryological, morphological, and biochemical evidence that demonstrate modern organisms evolved from older ancestral organism and species today are continuing to change over time.
THEORIES: Are supported by larger bodies of evidence and experimentation theories are never proven into laws, but are continuously refines.
LAWS: Are generalizations of patterns that occur repeatedly and predictably in nature.
What unique features did Tiktaalik have in terms of limb structure and breathing?
- It had a flat head
- Huge ribs which suggests lungs
- Hip bones which suggest its hind legs were evolving into legs
What is Darwins theory of natural selection?
- Organisms produce more offspring than can survive which leads to competition
- Variation is evident in populations and this is passed down in offspring
- Individuals suited to the environment survive to produce more offspring
- Change is slow and gradual
What factors encouraged the evolution of Tiktaalik?
Each structure it had suggests the fact that over time it was able to move its head, allowing it to look for prey when it peered out the water with its hind legs which eventually turned into legs making it easier for it to walk on land.
Structural Adaptations
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Behavioural Adaptations
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Physiological Adaptations
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