6.3.3 Speciation

• What is speciation?

  Evolutionary process of new species
• Genetic divergence makes interbreeding more likely to result in viable offspring.

  False
• Match the reproductive barrier with its mechanism:

  Habitat isolation ↔️ Species live in different areas

  Behavioral isolation ↔️ Different mating rituals

  Hybrid infertility ↔️ Hybrid cannot reproduce
• Order the stages of temporal isolation:

  1️⃣ Species breed at different times
• What is the role of isolation mechanisms in speciation?

  Prevent gene flow
• Match the reproductive barrier with its mechanism:

  Mechanical isolation ↔️ Reproductive parts incompatible

  Gametic isolation ↔️ Eggs and sperm incompatible

  Hybrid breakdown ↔️ Hybrid offspring have low fertility
• Hybrid infertility results in offspring that can reproduce successfully.

  False
• Allopatric speciation occurs when populations are geographically isolated
• Finches on the Galapagos Islands are an example of allopatric speciation.

  True
• What is the key difference between allopatric and sympatric speciation?

  Geographic isolation
• Allopatric speciation occurs when populations are geographically isolated.


  True
• Allopatric speciation occurs when populations are geographically isolated
• Allopatric speciation can result from geographic barriers preventing gene flow.

  True
• Allopatric speciation occurs due to geographic isolation and prevents gene flow.
• Match the key concept with its explanation and example:

  Allopatric Speciation ↔️ Formation of new species due to geographic isolation ||| Darwin's finches on Galapagos Islands

  Geographic Isolation ↔️ Physical separation of populations ||| Isthmus of Panama separating snapping shrimp

  Prevention of Gene Flow ↔️ Barriers block interbreeding between populations ||| Mountain ranges, oceans

  Independent Evolution ↔️ Populations evolve along separate trajectories ||| Adaptation to different environments
• What are the two categories of reproductive isolation mechanisms?

  Prezygotic and postzygotic
• Match the type of reproductive barrier with its mechanism:

  Prezygotic ↔️ Habitat isolation ||| Behavioral isolation

  Postzygotic ↔️ Hybrid inviability ||| Hybrid infertility
• Isolation mechanisms prevent gene flow between populations.
• Match the type of reproductive barrier with its example:

  Habitat isolation ↔️ Species live in different areas

  Temporal isolation ↔️ Species breed at different times

  Behavioral isolation ↔️ Different mating rituals

  Hybrid inviability ↔️ Hybrid fails to survive

  Hybrid infertility ↔️ Hybrid cannot reproduce
• An example of allopatric speciation is the adaptation of Darwin's finches to different islands in the Galapagos Islands.
• Mountain ranges can prevent gene flow between populations.


  True
• Prezygotic barriers occur before zygote formation.
• What is hybrid inviability in postzygotic isolation?

  Hybrid offspring fail to survive
• Order the steps of prezygotic reproductive isolation:

  1️⃣ Habitat isolation

  2️⃣ Temporal isolation

  3️⃣ Behavioral isolation

  4️⃣ Mechanical isolation

  5️⃣ Gametic isolation
• Genetic mutations can lead to reproductive isolation, such as changes in flowering time in plants.
• What is ecological specialization in sympatric speciation?

  Adaptation to use different resources
• What is the key difference between allopatric and sympatric speciation?

  Populations are physically separated
• Isolation mechanisms prevent gene flow between populations, leading to genetic divergence
• What are the two types of reproductive isolation?

  Prezygotic and postzygotic
• Habitat isolation is a type of prezygotic reproductive barrier that occurs when species live in different areas
• Hybrid inviability occurs when a hybrid offspring fails to survive.


  True
• Populations evolve in isolation and undergo genetic divergence
• Temporal isolation is a prezygotic reproductive barrier that occurs when species breed at different times
• What are the two primary mechanisms of speciation?

  Allopatric and sympatric
• What is an example of sympatric speciation?

  Apple maggot fly
• Order the stages of sympatric speciation in the apple maggot fly:

  1️⃣ Mutation leads to host preference

  2️⃣ Reproductive isolation occurs

  3️⃣ Genetic divergence accumulates

  4️⃣ New species arise
• What are the two primary mechanisms of speciation?

  Allopatric and sympatric
• What type of isolation is responsible for sympatric speciation?

  Reproductive isolation
• Match the type of speciation with its mechanism and example:

  Allopatric ↔️ Geographic isolation ||| Finches on the Galapagos Islands

  Sympatric ↔️ Reproductive isolation ||| Apple maggot fly
• What is an example of sympatric speciation?

  Apple maggot fly