Genetic Drift
Define Genetic Drift
Genetic drift is a mechanism of evolution that refers to random changes in allele frequencies within a population over time. These changes are not due to natural selection but are instead caused by chance events
What is a Gene pool?
The total sum of genes and all of their alleles of all of the individuals present in a population.
True or False: Natural selection is the only mechanism of evolution.
False. Genetic drift, gene flow, and mutation are also mechanisms of evolution
According to Lamarck's theory of evolution, if a woman gets a tattoo and then has a child, will the child also have a tattoo?
Yes, Lamarck's theory of evolution implies that traits inherited in an organism's lifetime will be passed onto the next generation (offspring)
Define genetic variation
Differences in DNA among individuals in a population.
Is genetic drift more significant in large or small populations? Why?
Small populations
Small populations, because random events have a greater impact on their gene pool.
Define Gene flow
Gene flow is the transfer of genetic material (alleles) from one population to another. This occurs when individuals from one population migrate and breed with individuals from another population
explain how camouflage helps an organism in natural selection
It increases an organism's chance of survival by making it less visible to predators. In relation to natural selection, organisms without camouflage are less likely to survive in comparison to organisms with camouflage.
Which scientist proposed "If you don’t use it, you lose it"?
Hint: Their theory was based on need
Lamarck/ Lamarck's theory of evolution
What's a mnemonic for remembering the taxonomic classification?
D, K, P, C, O, F, G, S
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Dang, kids prefer Coke over Fanta, generally speaking
Name one example of an event that can cause genetic drift.
Natural disaster, volcano, earthquake, floods, wildfires, hurricanes
How does migration cause gene flow?
Individuals move from one population to another and breed, introducing new alleles.
What is meant by the term 'Survival of the fittest'?
Individuals best adapted to their environment are more likely to survive and reproduce.
Charles ______ is known as the "____ __ ___ _____ __ _________"
Charles Darwin is known as the "Father of the Theory of Evolution"
What's one cause for genetic diversity?
Meiosis
Mutations
Inheritance (gamete combinations)
Can genetic drift lead to extinction in small populations? Explain why.
Yes. Because of random loss of allele variation, the population possesses less genetic variation and diversity, making the resulting population more vulnerable to environmental pressures and challenges
Why is gene flow important for maintaining genetic diversity in a population?
Gene flow could introduce new allele variants into the gene pool, making the population more diverse, which in turn, increases adaptability and reduces inbreeding.
If natural selection is a process where the environment determines which traits are passed on, then what is artificial selection?
A process where humans determine which traits are passed on
e.g. french pugs, bulldogs, australian shepards, crops
Why was Lamarck’s theory of use and disuse incorrect?
Because traits acquired during an organism’s lifetime cannot be inherited.
What was the mutation that Joey possessed?
Albinism
How does genetic drift differ from natural selection?
Genetic drift is random, natural selection is non-random based on fitness
Describe a real-world example of gene flow in animal populations. OR provide Mr. Dempsey with an example scenario
Yellowstone National Park wolves mix between packs and mix their genes.
Give an example of natural selection leading to a new species over time.
The evolution of finches on the Galapagos Islands involved the development of different beak shapes for different food sources.
What's one similarity between Lamarck's and Darwin's theory of evolution?
They both suggested that species change over time
I am the result of random changes in an organism's DNA. I can be helpful, harmful, or have no effect at all. I am one of the main sources of genetic variation in populations. What am I?
A mutation