• Laurie L.

Macroevolution and Microevolution

Updated: Oct 28, 2020


Evolution is made up of processes, concepts, and different methods that each express how the natural world around us changes. It is the small changes through generations of life. The genetic 'make up' of life, the environment, and many other factors all play a part in how things become different from each other. It leads people to assume that there’s big difference between the two. In this post, I’m going to explain the general concepts of both.


Discovery of Evolution

I have to mention CHARLES DARWIN, who was the author of THE ORIGIN OF SPECIES. He published his work on natural selection and changed the sciences forever. His work on finches showed us microevolution and macroevolution in a time where we were struggling through the ideas of where life came from. I would highly suggest at least reading a summary of his book because his work is a fundamental building block to the sciences today for understanding biology.

Charles Darwin

Alongside Charles Darwin is ALFRED RUSSEL WALLACE, who discovered natural selection independently from Charles at the same time and coauthored papers with him.

Alfred Russel Wallace

Macroevolution

When scientists talk about macroevolution, they’re specifically referring to the changes that have happened above the species level of life. This means that the species are at the crossroad and diverging down different paths from each other. These changes are caught in a moment of time like in our fossils, where we see a skeleton that is different from the older version of that species. The changes we can infer are an important part of science and macroevolution is simply a term used to define how these changes are interpreted while we're talking about them.

Let's infer by considering the sciences the massive amounts of math and calculations we had to use in order to get to the moon. We never went to the moon before so how did we get there? We had to infer the technology we’d need, the lack of gravity on the moon, and the distance. Scientists also had to infer how to get back from the moon without the astronauts burning up while re-entering our atmosphere or how to make sure we don’t fly by the earth and never make it back.


If you walk into someone’s house and the lights are on, you can infer that someone currently lives there. The more evidence you have without actually seeing the person in the house, the more you can infer that the person does live there without you having to see them directly. Seeing non-expired food in the fridge, a running fan, the microwave on with food in it etc. are all signs that let you infer that you're on the right track. The same pattern exists with comparing fossils and their structures.

MicroMacro Infographic was created by Laurie Luckritz at Biorender.com (2019)

Microevolution

Microevolution, which is generally accepted no matter what your religious beliefs are because it happens on a smaller scale of time. You can see the person standing in the house so you know someone is in there. It's the same process as macroevolution, but on a smaller scale. It’s defined as changes in allele frequencies (through the PROCESSES OF EVOLUTION within a population. It's a mouth full, but it means that a group of one species is slowly changing their genetic 'make up' collectively as they continue through the generations.

Here’s an example of microevolution: Let’s say there’s a lot of finches on an island and they all have different sized beaks because of their genes and alleles. If the only food on the island is either a type of nut that’s huge and tough or a tiny nut that’s hard to grab without precision, the beaks sizes of the finches become important. The finches with the biggest, strongest beaks can survive, live healthy, and have more children (offspring) because they can eat the big nuts better than finches without the big beaks. The finches with the longer, slimmer beaks can thrive too because they can eat the tiny nuts. Over time, you'd expect to see finches with large, big beaks and finches with long, slim beaks without much in-between. The finches without the special sized beaks will be starved or fewer in number because of the competition.



What’s important to realize about macroevolution and microevolution is that there’s no barrier between the lengths of time you’re talking about before you switch the term you use. You're just defining whether you're looking at long-term changes or short-term changes.



How It Comes Together

All of the circumstances leading up to the changes for both macroevolution and microevolution are the same. The difference between them is the point in time that you're looking at and how many changes have come together create a difference between them. There’s no known barrier to large changes because the small changes of microevolution accumulate into the big changes of macroevolution. You can’t separate the two forms of evolution from each other because they're the same thing just at different points of time for a species.

Sources:

Theories of Human Evolution: A century Debate, 1844-1944 by Peter J. Bowler

The Counter-Creationism Handbook by Mark Isaak

Undeniable: Evolution and the Science of Creation by Bill Nye

Evolution: What the Fossils Say and Why It Matters by Donald R. Prothero


#evolution #science #scienceducation #sciencecommunication #scicomm #scienceblog #blog #humanevolution #macroevolution #microevolution #Darwin #finches #undergraduateresearch

467 views0 comments

Recent Posts

See All