Questions and Answers
How do scientists measure biodiversity?
By using two measurement scales: species richness and species evenness.
How do scientists estimate the amount of species on Earth?
By counting how many different species are present in an environment.
What is phylogeny and how does it show patterns of relatedness between species?
Phylogeny is the expanding patterns of evolutionary relationships.
What are the processes that cause genetic diversity?
Signup and view all the answers
How do humans influence evolution?
Signup and view all the answers
What is Natural Selection? Know the 5 key ideas of Darwin's Theory.
Signup and view all the answers
How is evolution a random process? Explain the 5 processes that can lead to random changes in gene frequency.
Signup and view all the answers
What is the difference between allopatric speciation and sympatric speciation?
Signup and view all the answers
Study Notes
Measuring Biodiversity
- Biodiversity is measured using species richness (number of species in a specific area) and species evenness (relative proportion of individuals in each species).
Estimating Species on Earth
- Scientists estimate the number of species on Earth by counting species in various environments, considering factors like location, time, and visibility.
- Approximately 2 million species have been identified to date.
Understanding Phylogeny
- Phylogeny refers to the patterns of evolutionary relationships among species, created by analyzing shared traits.
- Greater similarity in traits suggests a closer evolutionary relationship between species.
Causes of Genetic Diversity
- Genetic diversity arises from recombination (chromosome alterations during reproduction) and mutations (random changes in genetic code).
- Microevolution involves evolution below the species level, while macroevolution leads to the emergence of new species.
Human Influence on Evolution
- Humans impact evolution through artificial selection, manipulating breeding to achieve desired traits in animals.
Natural Selection and Darwin’s Theory
- Natural Selection is the process by which individuals survive based on their adaptations to the environment, often summarized as "survival of the fittest."
- Darwin's five key points of his theory include:
- Excess offspring production
- Insufficient survival rates of all offspring
- Trait variation among individuals
- Heritability of trait differences
- Link between traits and survival/reproduction ability
- Fitness refers to an organism's capability to survive and reproduce, directly tied to adaptation via advantageous traits.
Randomness in Evolution
- Evolution can be random, influenced by five key processes:
- Mutation introduces random DNA changes.
- Gene flow occurs when individuals migrate between populations, altering genetic makeup unpredictably.
- Genetic drift involves changes in population genetics due to random mating.
- Bottleneck effect results in reduced genetic diversity from size reduction due to random events.
- Founder effect describes altered genetics from a small group of colonizers from a larger population, limited by the original genotypes.
Speciation Types
- Allopatric speciation occurs with geographic isolation, while sympatric speciation happens without such separation.
- Both processes can yield new species from a common genetic ancestor, facilitated by reproductive isolation and selective trait advantages in reproduction.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on biodiversity measurements with these flashcards from A.P.E.S. Chapter 5. Learn the key concepts of species richness and evenness, and how scientists estimate biodiversity. Perfect for studying and mastering this important ecological topic.
