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Science as Leisure

Liz Marchio

I am a trained ichthyologist interested in what gets people interested in natural history, biological sciences, and science careers. My passion is to find out what fuels curiosity for the natural world.

Biology-related serious leisure activities can impact people's interest in ecology, biology, and natural history. Do these activities promote biological understanding? If so, how does that progress and to what level does it progress to? 

If you're interested in a starting a dialogue, please feel free to contact me. If you're curious about how I got here, my story can be found on the About Me page.

 

Part 2: What is a species: Hybrids

My last blog post covered the biological species concept and some of the issues surrounding its use. This post builds on that introduction to "species".

At the end of the last post, I asked: What is another issue surrounding the use of the biological species concept (BSC)? 

A major problem with the BSC is it stipulates that species cannot interbreed. However, we see consistent examples of interbreeding across species. Here are a few examples of crosses, or "hybrids":

A lion x tiger cross = "Liger" or "Tigon". Photo credit: gwzoo.com

A lion x tiger cross = "Liger" or "Tigon". Photo credit: gwzoo.com

Horse x donkey cross = mule. These are yearling mules out of saddle and draft mares. Photo credit:  Deb Kidwell, Lake Nowhere Mule and Donkey Farm (Thanks, Deb!) 

Horse x donkey cross = mule. These are yearling mules out of saddle and draft mares. Photo credit:  Deb Kidwell, Lake Nowhere Mule and Donkey Farm (Thanks, Deb!) 

Trimaculatus cichlid x ??? x Parrot cichlid = "parrotfish" Photo credit: practicalfishkeeping.co.uk

Trimaculatus cichlid x ??? x Parrot cichlid = "parrotfish" Photo credit: practicalfishkeeping.co.uk

I don't know about you, but I definitely see a horse as a different species from a donkey and a tiger definitely different from a lion!

So, what's the deal?

If we define species by the BSC, where "species cannot interbreed"... are these seemingly distinct species actually ONE? Are lions and tigers one species??

As with ALL science, rules are hard to make for nature! 

If we rely on the biology of one "species" to differentiate it from others, there are always exceptions to the rule! In science as a whole, there are almost always exceptions to the rules!

Maybe that leaves a bad taste in your mouth. How do we know anything then? What's the point of science if it can't answer "basic" questions??

Well, yeah... How do we know anything? The answer is, we don't know anything for sure. A scientist will never tell you they are 100% sure of anything. We are humans and we are making the world around us into understandable parts. We see the diversity of life on earth and we want to name and categorize things. To do that, we use a system. Unfortunately, time does not stand still and things are always changing. The biological species concept does not take into account these kinds of things. There are other species concepts who do (evolutionary and phylogenetic species concepts, for example), but even those are flawed.

Maybe we get ligers and tigons because they are really closely related and haven't been separate species long enough. It takes TIME, lots and lots of time, for these kinds of changes to "be set in stone".

But, hey, that's one of the most amazing things about studying life on earth! There is no creation of a species. There is no "BAM!" you're a tiger and will always be a tiger.

We are trying to figure things out as we go. We are making theories and testing them. And, interestingly, we are hanging onto theories such as the biological species concept even though there are obvious exceptions. 

So what are your thoughts?


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