week 1- what is evolution Flashcards
What is sexual selection?
A mechanism of evolution where individuals with certain traits are more likely to find mates and reproduce
It includes both intrasexual and intersexual selection.
What are the ingredients for sexual selection?
Factors that contribute to the process of sexual selection
These include traits that enhance mating success.
What is the difference between (in)direct sexual selection?
(In)direct sexual selection refers to different ways traits can affect reproductive success, either directly through mate choice or indirectly through genetic benefits
Direct selection often involves traits that are attractive to the opposite sex.
What are the different types of selection in quantitative genetics?
Natural selection, sexual selection, artificial selection, and stabilizing selection
Each type affects the genetic composition of populations differently.
Define heritability in the context of evolution.
The proportion of variation in a trait that can be attributed to genetic differences among individuals
Important for understanding how traits can evolve.
What is the Price Equation?
A mathematical formulation that describes how average traits in a population change due to natural selection and other evolutionary forces
It links phenotype and fitness to evolutionary change.
What does phenotypic plasticity refer to?
The ability of an organism to change its phenotype in response to environmental conditions
Important for survival and adaptation.
What is individual-level selection?
Selection that acts on individual organisms based on their traits and reproductive success
It contrasts with group-level selection, which considers the success of groups.
What is social evolution?
The study of how social behaviors evolve and how they impact the survival and reproduction of individuals in a group
It includes concepts like cooperation and altruism.
How does game theory relate to predicting evolution of strategies?
Game theory models the strategic interactions among individuals, helping to predict behavior and evolution in competitive scenarios
It applies to various evolutionary strategies.
What is the definition of life?
Life is characterized by the ability to grow, reproduce, and respond to stimuli
It includes metabolic processes and genetic information.
What are the origins of life?
Life originated from simple chemical compounds through processes like prebiotic synthesis
This includes hypotheses like the ‘RNA world’ theory.
What is the significance of nucleic acids in the origins of life?
Nucleic acids store, transmit, and utilize genetic information, essential for life
DNA and RNA are the two main types.
What processes are involved in DNA replication?
DNA replication involves unwinding the DNA strand and synthesizing a complementary strand
This is crucial for cell division and inheritance.
What is the ‘primordial soup’ hypothesis?
The hypothesis that life began in a ‘soup’ of organic molecules in water, facilitated by environmental conditions
It suggests that early Earth had the right conditions for life to emerge.
What role do catalysts play in chemical evolution?
Catalysts speed up biochemical reactions necessary for the formation of complex organic molecules
They are crucial for processes like polymerization.
What is the ‘RNA world’ hypothesis?
The hypothesis that early life was based on RNA molecules that had the ability to replicate and catalyze chemical reactions
It suggests RNA was a precursor to DNA.
What is the importance of the Viking program in the search for life on Mars?
The Viking program aimed to detect life in Martian soil through experiments, with mixed results
It was one of the first missions to explore the potential for life beyond Earth.
What are protocells?
Simple, membrane-bound structures that may represent an early stage in the evolution of life
They are thought to be precursors to true cells.
What are the characteristics of prokaryotes?
Prokaryotes are unicellular organisms without a nucleus or membrane-bound organelles
They include bacteria and archaea.
What evidence supports the endosymbiotic theory?
Mitochondria and chloroplasts resemble prokaryotic cells and have their own DNA, supporting the idea they originated from free-living bacteria
This theory explains the origin of eukaryotic cells.
What is the Cambrian explosion?
A rapid diversification of life forms that occurred around 500 million years ago
It marks a significant increase in the complexity of life.
What does the fossil record indicate about evolution?
The fossil record provides evidence of past life forms and their changes over time, supporting the theory of evolution
It shows common ancestry and descent with modification.
What are homologous features?
Similar structures in different species that indicate a common ancestor
They can arise from divergent evolution.
What are the main mechanisms of evolutionary change?
Mutation, gene flow, genetic drift, non-random mating, and natural selection
These mechanisms influence the genetic composition of populations.
What is the significance of genetic variation in evolution?
Genetic variation is essential for natural selection to act upon, leading to adaptation and evolution
It allows populations to respond to environmental changes.
What is adaptation in the context of evolution?
A trait that increases an organism’s chances of survival and reproduction in a specific environment
Adaptations result from the process of natural selection.
What role does the environment play in evolutionary change?
The environment imposes selection pressures that influence which traits are beneficial and thus favored in evolution
It affects phenotype expression and survival.
What are quantitative traits?
Traits influenced by multiple genes and often affected by environmental factors, showing a continuous distribution
Examples include height and growth rate.
What is the role of development in evolutionary change?
Development can influence evolutionary trajectories by affecting how traits are expressed and selected for
It links genetic and phenotypic variation.
What are the three propositions of Darwin’s theory of evolution?
- Species change over time
- Divergent species share a common ancestor
- Changes can be explained by natural selection
These propositions form the foundation of evolutionary biology.
What is the phylogenetic tree of life?
A diagram that represents the evolutionary relationships among various species based on their common ancestry
It illustrates how species are related through evolution.
What does extinction refer to in evolutionary terms?
The permanent loss of a species from Earth
Extinction events can lead to increased diversity in surviving species.
What is evolution?
Exploration of ecology, constrained by selection.
What does the emphasis on the lowest mechanistic level in evolution refer to?
Focus on individual biological processes and mechanisms.
What are emergent properties in the context of evolutionary explanations?
Characteristics that arise from complex systems that cannot be understood by examining individual parts alone.
What are the factors internal to organisms that influence evolution?
Genetic makeup, developmental processes, and physiological traits.
What are the factors external to organisms that influence evolution?
Environmental pressures, ecological interactions, and geological changes.
List the different research agendas that provide a broader view on evolutionary explanations.
- Population genetics
- Quantitative genetics
- Developmental plasticity
Define genotype.
The genetic constitution of an individual.
Define phenotype.
The observable characteristics or traits of an individual.
What is developmental plasticity?
Phenotypes that are transformed by development, breaking the genotype-phenotype link.
What key evolutionary concepts are discussed in this module? List them.
- Genetic drift
- Gene flow
- Developmental plasticity
- Niche construction
- Phenotypic plasticity
- Kin selection
What did Charles Darwin describe about worms?
Worms tunnel into the soil and produce casts by ingesting soil and vegetable matter.
What is niche construction?
How organisms change over time and the relation of these changes to their environments.
How does the atmosphere influence life on Earth?
The atmosphere provides essential gases and conditions for biological processes.
What is the state of Earth’s atmosphere in relation to thermodynamic equilibrium?
It is far from thermodynamic equilibrium, as evidenced by the presence of oxygen.
What is significant about Titan, Saturn’s largest moon?
Titan has oceans of methane and may harbor life different from that on Earth.
What is anthropomorphism?
Interpreting non-human entities in terms of human characteristics.
What is not generally seen as a useful tool in the scientific method?
Empathy.
What were some lines of evidence for evolution discussed in Week 1?
- Fossils
- Homologies
What is the relationship between evolution and development?
Evolutionary changes can influence developmental processes and vice versa.
Fill in the blank: The scientific method involves observation, definition, and _______.
[measurement]
True or False: Humans are no longer evolving.
False.
What is the adaptive value of traits?
The benefit provided by a trait that increases an organism’s fitness in its environment.
