Evolutionary Mechanisms
What is the process by which organisms change over time through variations and selection?
Evolution
What is an adaptation?
A trait that improves an organism's ability to survive and reproduce in its environment
Why is survival important for reproduction?
Survival allows organisms to reach reproductive age and produce offspring
What are selective pressures?
Environmental factors that influence which individuals in a population are more likely to survive and reproduce
What is genetic variation?
Differences in DNA sequences among individuals within a population
What term describes the change in allele frequencies within a population over generations?
Microevolution
Name an example of a behavioral adaptation.
Migration in birds or hibernation in bears
How do organisms with advantageous traits tend to reproduce compared to others?
Organisms with advantageous traits generally have higher reproductive success
Give an example of a selective pressure in nature.
Predation, competition for resources, or environmental changes
Why is genetic variation important for the survival of a species?
It provides a pool of traits that can be advantageous under changing environmental conditions
How does natural selection lead to the evolution of a population?
Differential survival and reproduction of individuals due to differences in phenotype
How does a physical adaptation differ from a behavioral adaptation?
A physical adaptation involves structural changes in an organism, while behavioral adaptations involve changes in actions or habits
Describe a trade-off between survival and reproduction in an organism.
Allocating resources to reproduction might reduce resources available for survival, such as in cases of high energy expenditure for offspring
How might selective pressures lead to the development of antibiotic-resistant bacteria?
Selective pressures from antibiotic use kill susceptible bacteria, allowing resistant bacteria to survive and reproduce
How can sexual reproduction contribute to genetic variation?
Sexual reproduction combines genetic material from two parents, resulting in offspring with new combinations of genes
Name a mechanism of evolution other than natural selection.
Genetic drift, gene flow, or mutation
How might an adaptation that is beneficial in one environment become a disadvantage in another?
Environmental changes can make previously beneficial adaptations less advantageous or even harmful
How does sexual selection differ from natural selection?
Sexual selection is based on traits that improve mating success, while natural selection is based on traits that improve survival
How can human activities influence selective pressures on wildlife?
Human activities such as habitat destruction, pollution, or hunting can create new selective pressures or intensify existing ones
How might genetic mutations contribute to variation within a population?
Genetic mutations introduce new alleles into a population, creating additional sources of variation
How does mutation contribute to evolutionary change within a population?
Mutations introduce new genetic variations into a population, which can create new traits that may be subject to natural selection.
Explain how an adaptation can arise through random genetic mutations.
Mutations can introduce new traits, and if these traits enhance survival, they may become more common in a population over time
How might an increase in predation pressure affect reproductive strategies?
Increased predation might lead to increased investment in offspring survival strategies, such as more frequent reproduction or more protective behaviors
Explain how climate change might alter selective pressures on a species.
Climate change can shift habitat conditions, affecting which traits are beneficial and potentially leading to changes in species distribution or evolution
How can environmental factors influence the level of genetic variation within a population?
Environmental factors, such as climate, availability of resources, and presence of predators, can affect which traits are advantageous and thereby influence the level of genetic variation by favoring certain traits over others