Can Microevolution Lead to Macroevolution?

No matter how controversial the Theory of Evolution is in some circles, it is rarely argued that microevolution happens in all species. There is pretty significant amounts of evidence that DNA changes and in turn can cause small changes in the species, including thousands of years of artificial selection via breeding. However, the opposition comes when scientists propose that microevolution over very long periods of time can lead to macroevolution. These small changes in DNA add up and, eventually, new species come into being that can no longer breed with the original population.

After all, thousands of years of breeding different species has not led to completely new species being formed. Doesn't that prove that microevolution does not lead to macroevolution? Proponents for the idea that microevolution leads to macroevolution point out that not enough time has gone by in the scheme of the history of life on Earth to show if microevolution does lead to macroevolution. However, we can see new strains of bacteria forming since the life span of a bacterium is very short. They are asexual, though, so the biological definition of species does not apply.

The bottom line is that this is one controversy that has not been solved. Both sides have legitimate arguments for their causes. It may not be solved within our lifetimes. It is important to understand both sides and make an informed decision based on the evidence that fits in with your beliefs. Keeping an open mind while remaining skeptical is often the hardest thing for people to do, but it is necessary when considering scientific evidence.

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Basics of Microevolution

Changes in DNA cause microevolution
A DNA Molecule. Fvasconcellos

Microevolution is the changes in species at a molecular, or DNA, level. All species on Earth have very similar DNA sequences that code for all of their characteristics. Small changes can happen through mutations or other random environmental factors. Over time, these can affect the available traits that can be passed down through natural selection to the next generation. Microevolution is rarely argued and can be seen through breeding experiments or studying population biology in various areas.

Further Reading:

  • Microevolution: A brief definition of microevolution and how it relates to the Theory of Evolution.
  • DNA and Evolution: How is DNA related to evolution? This article examines microevolution at a more in depth level and ties evolution to genetics.
  • Processes of Microevolution: What drives microevolution? Learn about the 5 ways microevolution happens in any given species and why they happen.
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Changes in Species

Speciation is the way macroevolution happens
Types of Speciation. Ilmari Karonen

Species do change over time. Sometimes these are very small changes caused by microevolution, or they may be larger morphological changes describe by Charles Darwin and now known as macroevolution. There are different ways species change based on geography, reproductive patterns, or other environmental influences. Both proponents and opponents of the microevolution leading to macroevolution controversy use the idea of speciation to support their arguments. Therefore, it does not really settle any of the controversy.

Further Reading:

  • What is Speciation?: This article defines speciation and touches on the two opposing theories about the pace of evolution - gradualism and punctuated equilibrium.
  • Types of Speciation: Go a little bit deeper into the idea of speciation. Learn the four different ways speciation occurs - allopatric, peripatric, parapatric, and sympatic speciation.
  • What is the Hardy Weinberg Principle?: The Hardy Weinberg Principle could eventually be the link between microevolution and macroevolution. It is used to show how allele frequency within a population changes over generations.
  • Hardy Weinberg Goldfish Lab: This hands on activity models a population of Goldfish to reinforce how the Hardy Weinberg Principle works.
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    Basics of Macroevolution

    All species on Earth are related
    Phylogenetic Tree of Life. Ivica Letunic

    Macroevolution was the type of evolution Darwin described in his time. Genetics and microevolution were not discovered until after Darwin died and Gregor Mendel published his pea plant experiments. Darwin proposed that species changed over time in morphology and anatomy. His extensive study of the Galapagos finches helped shape his Theory of Evolution through Natural Selection, which is now most often associated with macroevolution.

    Further Reading:

  • What is Macroevolution?: This brief definition of macroevolution discusses how evolution happens on a larger scale.
  • Vestigial Structures in Humans: Part of the argument for macroevolution involves the idea that some structures in species change functions or become functionless all together. Here are four vestigial structures in humans that lend support to that idea.
  • Phylogenetics: Species similarities can be mapped in a cladogram. Phylogenetics shows the evolutionary relationships between species.
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    Your Citation
    Scoville, Heather. "Can Microevolution Lead to Macroevolution?" ThoughtCo, Feb. 28, 2016, thoughtco.com/microevolution-to-macroevolution-1224825. Scoville, Heather. (2016, February 28). Can Microevolution Lead to Macroevolution? Retrieved from https://www.thoughtco.com/microevolution-to-macroevolution-1224825 Scoville, Heather. "Can Microevolution Lead to Macroevolution?" ThoughtCo. https://www.thoughtco.com/microevolution-to-macroevolution-1224825 (accessed May 21, 2018).