Ring Species and the Fallacy of the Discontinuous Mindset

“Species” is not a discontinuous concept, but a fluid one. For example, imagine you’re baking a cake that needs to be baked for 30 minutes. If you took it out at 29 minutes and 59 seconds, it would still be “done”, would it not? The same goes for 29 minutes 58 seconds. However, if you took it out at 10 minutes, it wouldn’t be done. But it’s nearly impossible to pinpoint the second that it becomes “done”. An example of the fluidity of species are special cases known as ring species, where you have a series of subspecies that can interbreed with their neighboring, closely-related subspecies, but the two at the ends of this spectrum cannot breed with each other (see diagram below).

 

Also doubles as a guide on how to make crescent rolls.

A group of salamanders in California illustrate this point beautifully. At the South end of the Central Valley, you find two very distinct species, Ensatina eschscholtzi and Ensatina croceater. However, as you work your way up and around the Northern tip of the valley, you see a constant blending from one species to the other, and when they meet back up again at the tip, they are two separate species. But a specimen from the Southern part could mate with one from 20 miles further north, as that specimen could mate with another salamander another 20 miles further north, continuing on in an unbroken chain around to the other species back at the origin of this loop.

o89220540

Whoever made this better have added “salamander cartography” to his resume.

Another good example is that of herring gulls and lesser black-backed gulls around the arctic circle. Either way, a ring species is showing us spatially what normally happens temporally. These things are often difficult to comprehend with our discontinuous mindset, where a species is a fixed concept. Humans and chimps have a similar strand of gradual continuity between each other, except the intermediates happen to be dead.

These ring species are easy to explain through evolution, but difficult to explain via Intelligent Design (unless we’re assuming the designer wanted to design evidence of evolution). This concept is also directly linked to when a new species “appears”. With the exception of polyploidy, new species never “pop up”. This is known as saltation, and is a direct refutation of evolution. This is why we don’t see things like a chimp giving birth to a human, or Kirk Cameron’s beloved crocoduck.

Image

Instead, over the last six million years there has been a steady progression between a chimp-like ancestor and modern human. There was never one point where “voila!” we have a human. If we could get a time machine, we could transport a modern human back 2000 years, and they would be able to successfully mate with a human of 2000 years ago (biologically… socially this would be quite difficult, and likely rather repulsive considering the relatively recent invention of soap). Likewise, we could take that person of 2000 years ago, and transport them back another 2000 years, where they would be able to successfully mate with a human of 4000 years ago, and on and on back, in the world’s first time travel breeding experiment.

The ring species is excellent evidence for evolution. It’s the kind of thing we expect to find if we think species are evolving. However, assuming a static history of life (as we’d see if life was designed to not evolve), this is completely illogical and antithetical to the concept (unless we counter for some sort of whimsy and mischief on the part of the designer). Of course, if someone has an explanation for this, I’d be more than willing to hear it.

Image

Advertisements

~ by kriskodisko on August 5, 2013.

8 Responses to “Ring Species and the Fallacy of the Discontinuous Mindset”

  1. Makes sense. Although I think it is sad that you try to explain evolution to people of our age. I assume if somebody in their 20s has not yet understood something we understood when we were 10 than that person must obviously not have the mental ability to understand abstract concepts like that. So I think trying to explain it over and over again is just like saying “You’re stupid” over and over…

  2. This explains the jackalope! 🙂 Seriously, though, the concept of proximal mating is the most sensible explanation- in that the soil, water and climate are simply more conducive to such a process, from a closer environment.

  3. Whenever I talk to creationists—which happens with surprising frequency—they are quick to say, “I believe in microevolution but not macroevolution.” I have three responses to that. First, I try to explain that unless they can demonstrate a mechanism that actively prevents species from changing beyond a certain point, there is no reason to believe, scientifically, that “microevolution” won’t lead to “macroevolution.” Second, that given reproduction, adaptation and selection, evolution is a given unless there is a mechanism to prevent it. The burden of proof is on the one who says change can’t happen: why can’t it happen? And third, I point out ring species as a clear, demonstrable instance of “macroevolution.” (I always use larus gulls, as they make a clear geographic ring of the planet, which I think is easier to visual sans chart.) And at this point the creationist, without fail, gives the same response: “But they’re still birds.” And if I don’t give up in frustration at this point, I point out that they’ve punted, moved from species to class, which they usually claim was their meaning all along.

    I know I’m not teaching you anything, but I was wondering if you can see any weaknesses or inaccuracies in my presentation. Is there a way for it to go better than this?

    • Remind them that of they’ve shifted the burden to class, then they have no problem with seals, pandas and weasels having evolved in the last 5000 years, which means they believe in super evolution. Also, if we back up to class, then chimps and humans are lumped together as well. It’s a shifting goalposts kind of argument, and you’ll never change their minds in that very conversation, but maybe you can plant the seeds of doubt.

  4. […] all these sub-populations remain a single species, except in the case of my favorite example, the ring species. Do this process many times on many different species and it will become apparent that there is an […]

  5. […] Ring species (see a cool look at some of these here) […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

 
%d bloggers like this: