1. Summary

The video chosen is about speciation, and how things can affect speciation. It begins to explain isolation and the factors that can have on speciation. Then finally the video breaks down of the patterns of evolution.

2. Why Watch This Video?

  • Have you ever wondered why more interbreeding in nature has not happened?
  • Would you like to know how reproductive isolation works? And how it can affect species?
  • Have you ever been confused about why certain species look alike and have similar traits but are not from a common ancestor?

3. Key Terms

  • Species: A group of living things, that can interact with each other and create new beings by interbreeding and can create fertile babies.
  • Natural Selection: When animals and plants are adapted to their environment to survive. Natural selection makes sure only the organisms best suited for their environment will survive and reproduce.
  • Genetic Drift: When events alter the genetic variations in a population by removing individuals for reasons unrelated to their fitness for the environment.

4. Loose Ends

Speciation does not only happen in animals.

Speciation can also happen in plants. This video only focused on speciation through animals, but it also happens in plants similarly to animals.

There are four types of speciation.

Allopatric speciation is when speciation occurs through geographical isolation. “Allo” means other and “patric” means place, so it literally means in an “other place.” Peripatric speciation runs along with allopatric speciation but is the more extreme version of it, occuring when only some individuals are isolated, or when most members a species are killed off and only a few remain. Paraptric speciation is when there is nothing stopping organisms from interbreeding, but they just choose not to do so. The final one is sympatric speciation, which relies heavily on reproductive isolation; organisms are in the same places but do not interbreed because of reproductive isolation and mating season happening at different times.

How long does speciation take?

Broad changes in a population can happen rapidly—even over decades—but research suggests that for changes to really set in, at least 1 million years is required. Josef Uyeda, lead author on a study of evolution rates, put it this way: “This isn’t just some chance genetic mutation that takes over.… Evolutionary adaptations are caused by some force of natural selection such as environmental change, predation or anthropogenic disturbance, and these forces have to continue and become widespread for the change to persist and accumulate. That’s slower and more rare than one might think.”  Read more: Not so fast — researchers find that lasting evolutionary change takes about one million years. (Phys.org)

5. Self-Test Questions

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