Unit 7 Quiz 2 Part 1 Flashcards
What is phylogeny?
Visual representations of speciation events and hypothesized evolutionary relationships between species.
How are phylogenetic models generated?
Based on morphological and molecular similarities.
Are phylogenetic models static?
No, they are constantly revised as new evidence becomes available.
What are the two types of phylogenetic models?
- Cladograms
- Phylogenetic Trees
What’s a cladogram
What’s a phylogenetic tree
What’s a node? Why does it represent?
What’s a synapomorphy?
What’s a monophyletic group?
What’s an outgroup
What do all species branching from a node share?
A common ancestor.
This indicates that they have inherited traits from that ancestor.
What do species descending from a common ancestor have?
The traits it had.
This suggests that traits are passed down through generations.
What is the relationship between two species that branched apart more recently?
They are more closely related.
This implies a shorter evolutionary distance between them.
What do evolutionary trees illustrate?
Evolutionary relatedness
What are the two types of evolutionary trees?
- Phylogenetic trees
- Cladograms
What do phylogenetic trees depict?
Ancestral relatedness with regard to length of time between speciation events
What evidence do phylograms use to show ancestral lineage?
- Fossil evidence (when available)
- Molecular evidence
What do cladograms depict?
Ancestral relationships without regard to time
What do cladograms rely on to show ancestral lineages?
Shared, derived characters
What is a shared, derived character?
An evolutionary novelty unique to a clade
What are shared derived traits?
New characteristics that appear in a group of organisms and are passed down to their descendants.
Why is it called ‘shared’ derived traits?
‘Shared’ because more than one organism has it.
Why is it called ‘derived’ in shared derived traits?
‘Derived’ because it’s different from what their ancestors had.
Give an example of a shared derived trait of birds.
Feathers.
Do all modern birds have feathers?
Yes, all modern birds have feathers.
Did the dinosaur ancestors of birds have feathers?
No, their dinosaur ancestors did not have feathers.
What is a shared derived trait of mammals?
Mammary glands, which produce milk.
What is cladistics?
The grouping of organisms by common descent
Cladistics focuses on the evolutionary relationships among species.
What is a clade?
An ancestral species and all of its descendants
Clades are used in cladistics to represent evolutionary branches.
What defines a valid clade?
It is monophyletic, consisting of the ancestor and all of its descendants
Monophyletic groups are crucial for accurate phylogenetic analysis.
What is the outgroup in a cladistic analysis?
The species least related to the others in the tree
The outgroup serves as a reference point for comparing evolutionary traits.
What is the Rule of Maximum Parsimony?
A principle used to determine where characteristics were gained or lost in an evolutionary lineage.
What does the Rule of Maximum Parsimony state?
The explanation for an event should be made with the fewest possible assumptions.
What is another name for the Rule of Maximum Parsimony?
The simplest explanation for an event is usually correct.
What type of evidence is considered more significant than morphological evidence when determining evolutionary relationships?
Molecular evidence
Molecular evidence provides a more precise understanding of evolutionary relationships.
Why is molecular evidence considered more accurate than morphological evidence?
Molecular evidence is less likely to be influenced by environmental factors or convergent evolution
Morphological evidence can be affected by these factors, leading to potential inaccuracies.
What advantage does molecular evidence have in terms of data quantity?
There are thousands of genes and millions of base pairs available for analysis
This extensive data allows for more precise comparisons between organisms.
What ability does molecular evidence have that morphological evidence lacks?
Molecular evidence can detect evolutionary changes not always visible in morphology
This makes molecular evidence more reliable for identifying evolutionary relationships.
True or False: Morphological data is not valuable when studying fossils.
False
Morphological data is particularly useful when molecular data is unavailable, such as in fossil studies.
Fill in the blank: Molecular evidence is more reliable since mutations are unlikely to occur from _______.
convergence
This reduces the chances of misinterpretation in evolutionary relationships.
What is artificial selection?
The process by which humans modify other species by selecting and breeding individuals with desired traits
Artificial selection is a key concept in understanding how domesticated species have evolved through human intervention.
Who noted the concept of artificial selection?
Darwin
Charles Darwin is known for his contributions to the theory of evolution and the concept of natural selection.
What role do humans play in artificial selection?
Humans select and breed individuals with desired traits
This selection process can lead to significant changes in the traits of domesticated species over generations.
Fill in the blank: Darwin noted that humans have modified other species by selecting and _______ individuals with desired traits.
breeding
Breeding involves mating selected individuals to enhance specific characteristics in the offspring.
What is convergent evolution?
Convergent evolution is the evolution of similar, or analogous, features in distantly related species.
Convergent evolution highlights how different species can develop similar traits independently due to similar environmental pressures.
What does convergent evolution provide evidence of?
Convergent evolution is evidence of natural selection.
Natural selection drives the adaptation of species to their environments, resulting in similar traits among unrelated species.
Does convergent evolution provide ancestral data?
No, convergent evolution does not provide ancestral data.
This is because it involves unrelated species developing similar traits, which do not indicate a common ancestry.
What are analogous structures?
Analogous structures have functional similarity but structurally differ.
Examples include the wings of bats and birds, which serve the same function but have different structural origins.
What are homologous structures?
Structures that share ancestry and have similar underlying anatomy, but may have similar or different functions.
Example: Vertebrate limbs such as a human arm and a bat wing.
What is a key characteristic of homologous structures?
Shared ancestry.
Homologous structures arise from a common evolutionary origin.
Give an example of homologous structures.
Human arm and bat wing.
Both have similar bone structures but serve different functions.
What are analogous structures?
Structures that have different ancestry but similar functions and dissimilar anatomy.
Example: Butterfly wing and bird wing.
What distinguishes analogous structures from homologous structures?
Different ancestry.
Analogous structures evolve independently to serve similar functions.
Give an example of analogous structures.
Butterfly wing and bird wing.
Both serve the function of flight but have different anatomical structures.
Which type of structure may have similar functions but different anatomical features?
Analogous structures.
They evolve under similar environmental pressures but are not derived from a common ancestor.
True or False: Homologous structures always serve the same function.
False.
Homologous structures can have similar or different functions.
True or False: Analogous structures arise from a shared evolutionary ancestor.
False.
Analogous structures develop independently despite having similar functions.
