Introduction to Evolution and Natural Selection quiz #5 Flashcards
Introduction to Evolution and Natural Selection quiz #5
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What does 'descent with modification' mean in the context of evolution?
'Descent with modification' means that species share common ancestors, but change occurs over generations, leading to differences among descendants. What is meant by 'fitness' in evolutionary biology?
Fitness refers to the likelihood that an individual contributes offspring to the next generation. What is an adaptation?
An adaptation is a trait that makes an organism well suited to its environment. Why is variation important in understanding evolution?
Variation provides the raw material for natural selection to act upon, enabling populations to evolve over time. What is the difference between ladder thinking and tree thinking in biology?
Ladder thinking arranges species in a hierarchy of complexity, while tree thinking focuses on evolutionary relationships and common descent. What does a phylogenetic tree represent?
A phylogenetic tree represents the evolutionary relationships among species based on common descent. What do the nodes on a phylogenetic tree represent?
Nodes represent common ancestors of the populations that branch from them. Why is it incorrect to describe some species as 'higher' or 'lower' organisms?
Because all species have been evolving for the same amount of time and complexity varies in different ways; evolutionary relationships are not hierarchical. What is the significance of common descent in evolution?
Common descent explains why different species share traits and provides a framework for understanding evolutionary relationships. How does natural selection affect the frequency of traits in a population?
Traits that improve survival and reproduction become more common in the population over generations. What is meant by 'survival of the fittest'?
'Survival of the fittest' refers to individuals with traits that increase their reproductive success being more likely to pass on those traits. Why is reproduction more important than survival in the context of natural selection?
Because only individuals that reproduce pass their traits to the next generation, influencing evolutionary change. How does the concept of average relate to population thinking?
In population thinking, the average is a statistical measure, and no individual is average in every trait; variation is key. Why is typological thinking insufficient for understanding evolution?
Typological thinking ignores variation, which is essential for natural selection and evolutionary change. What is the role of phylogenetic trees in studying evolution?
Phylogenetic trees help visualize and understand the evolutionary relationships and common ancestry among species. How does adaptation arise in a population?
Adaptation arises when natural selection increases the frequency of beneficial traits in a population. What is the relationship between adaptation and environment?
Adaptations are traits that improve an organism's fit to its specific environment. How does the concept of 'descent with modification' explain both similarities and differences among species?
Similarities arise from shared ancestry, while differences result from modifications over generations. What is the importance of using population thinking in evolutionary biology?
Population thinking recognizes the significance of variation, which is essential for natural selection and evolution. How do evolutionary trees help answer questions about shared traits among species?
They show which species share a common ancestor, explaining why they have similar traits. What does it mean when two species share a recent common ancestor on a phylogenetic tree?
It means they are more closely related to each other than to species with a more distant common ancestor. Why is it misleading to use the term 'average' to describe an individual in a population?
Because the average is a statistical construct, and no individual possesses all average traits; real populations are diverse. How does natural selection differ from other mechanisms of evolution?
Natural selection specifically favors traits that enhance survival and reproduction, while other mechanisms may change traits randomly. What is the main focus of tree thinking in evolutionary biology?
Tree thinking focuses on evolutionary relationships and common descent among species. How does the concept of 'survival of the fittest' relate to reproductive success?
It emphasizes that individuals who reproduce more successfully are considered more 'fit' in evolutionary terms. What is the significance of nodes in a phylogenetic tree?
Nodes indicate the most recent common ancestor of the branches that diverge from them. How does variation within a population contribute to evolution?
Variation provides different traits for natural selection to act upon, enabling populations to adapt and evolve. Why is it important to avoid hierarchical thinking when studying evolution?
Because evolutionary success is about adaptation to the environment, not about being more or less complex. What does it mean for a species to be 'well adapted'?
A well-adapted species has traits that allow it to survive and reproduce effectively in its environment. How do evolutionary trees illustrate the concept of common descent?
They trace the lineage of species back to shared ancestors, showing how species diverged over time. What is the role of reproductive success in natural selection?
Reproductive success determines which traits are passed on and become more common in the population. How does the environment influence which traits are favored by natural selection?
Traits that improve survival and reproduction in a specific environment are favored and become more common. Why is it important to recognize the diversity within a species?
Recognizing diversity is essential because it is the basis for natural selection and evolutionary change. How does the concept of 'descent with modification' relate to the diversity of life?
It explains how diverse species arise from common ancestors through gradual changes over time. What is the primary mechanism of evolution discussed in this topic?
Natural selection is the primary mechanism of evolution discussed. How do phylogenetic trees help scientists understand evolutionary history?
They provide a visual representation of how species are related through common ancestors. What is the difference between a branch and a node on a phylogenetic tree?
A branch represents a lineage over time, while a node represents a common ancestor where lineages split. Why is it important to focus on evolutionary relationships rather than complexity?
Because evolutionary success depends on adaptation, not on being more complex. How does natural selection explain the presence of specific adaptations in organisms?
Natural selection increases the frequency of traits that help organisms survive and reproduce in their environment. What is the significance of the phrase 'all populations have been evolving for the same amount of time'?
It means no living species is more 'advanced' than another; all have evolved since their last common ancestor.
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