But AmoebaMike, what else do I need to know about taxonomy and evolution?

In order to standardize names of organisms, back in the the 1700s, a Swedish botanist named Carl Linnaeus developed a two-name system. Referred to as, binomial nomenclature, it is the system with which we use–even still today–for naming organisms.

Carl von Linné, Alexander Roslin, 1775.
Scientific Hottie
Carl Linneaus,
Image via Wikipedia

The word binomial means “two names.” So it is by using two names that we fully name each organism, in the same way that you have both a first and a last name. In binomial nomenclature, the first of the two names indicates the genus name. A genus is a group of closely related species. The second name is the species name; often it is a Latinized version of a word that describes a trait of the species, a location where the species can be found, or even an influential person in the discovery or science of that particular species. See the accompanying image.

Click for full size

Finally, you need to know how organisms are classified. Scientists try to make maps, or trees, called cladograms to show the relationship between different species. It used to be that organisms that were organized in cladograms based on physical similarities the species shared with one another. For example, as the name implies, the horseshoe crab looks like a crab.  In fact, it’s actually more related to spiders than it is to crabs!

Now that science has advanced greatly in the past half-century or so, cladograms are built using information scientists gather from DNA and RNA sequencing.  We’re finding out that like the horseshoe crab, some things we thought were related aren’t really all that close!  Have you ever heard of a panda or a koala being referred to as panda bear or koala bear?

Bears are members of the family Ursidae.  The bears you think of when you hear the term “bear”, like the grizzly bear and the polar bear are in genus Ursus.  Ursus is one of the genera of family Ursidae. Pandas are members of family Ursidae, but their genus is Ailuropoda. So they’re technically bears!

Koalas share the same class as the bears, Mammalia.  That’s as close as they’re related.  Koalas aren’t bears any more than dogs or whales are bears.

One last note: as you see in the image, the proper way to discuss a species is using the full name and italicizing it. The genus name gets capitalized, but can also be abbreviated by the first initial. For example, koalas would be Phascolarctos cinereus or P. cinereus and pandas would be Ailuropoda melanoleuca or A. melanoleuca.

Evolution

We recently covered Taxonomy here at AmoebaMike.  Taxonomy, a way of classifying organisms, fits very well with evolution.

There is of course an issue with evolution: the hot topic that pits “religion vs science”.  That of course is hogwash as the Pope (more than one) came out and said that evolution is not some fad hypothesis. But then of course, plenty of other Christians really dislike Catholics so that’s not enough for some people.  It’s an argument that probably takes over 6% of the internet already, and I won’t replay it here. I just wanted to point out that it is a hot button issue.

So moving past the issue of man being created in the image of God, evolution can actually tell you a lot. It shows how different species are related to each other. For example, did you know that you have more in common with a whale, than a whale has in common with a shark?

While sharks and whales both live in the ocean, sharks are actually a type of fish that doesn’t have bones. Whales, on the other hand, are mammals. And like humans, which are also mammals, whales suckle their young. Sharks are cold-blooded and whales are warm-blooded. Sharks breathes through their gills underwater and whales breathe air through their lungs.

You are even more closely related to a sea anemone than the sea anemone is to an oak tree despite the fact that they pretty much just stick around in the same place.

How do you determine who you’re closely related to?

The same way you do with people!

Let’s take person A.  You’re related to person A.  How do you know is person A is your sibling? Look at your parents. Do you share parents? No? Do you share grandparents? If yes, person A is either an uncle/aunt or a cousin!

Looking at other organisms, primates like chimps are closely related to humans because a long time ago (a very, very long time) they shared a common ancestor.  Even further back, we share a common ancestor with a cat. Further in the past, we share a common ancestor with a jellyfish. And still further, we share an ancestor with a rose plant.

Does that mean you came from a chimp? a cat? a jellyfish? a rose plant? Of course not!  You didn’t come from any of those organisms any more than you came from your cousin or your uncle just because you share a common grandparent!

Through much hard work, including gene sequencing, a giant family tree is being constructed. Only it’s not like Geni where you can how closely you’re related to President Obama; it’s actually a tree of all life.  Fittingly, it’s called the Tree of Life. Check it out!

See also:

Taxonomy

Taxonomy is a pretty simple biological concept, but can be rather tricky in practice.

Classifying living things in groups that share similar characteristics is what taxonomy is all about.  For example, here’s a group of things you might find on a desk:

Rubber bands, pens, staples, paper clips, pencils

In order to classify these things we can look at the purpose for each item and group them based on that:

Rubber bands, paper clips, and staples are used to secure things to one another. Pens and pencils are for writing.

Now let’s look at what they’re made of:

Staples and paper clips are metal, whereas rubber bands are not. Pens are plastic and pencils are wooden.

So we have just made these groups:

Taxonomy

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Of course, this is simple taxonomy. It gets way more complex when you’re talking about the billions of species that live or ever have lived on our planet.

Taxonomy trees, such as the one above are excellent visuals for understanding evolution, which I plan on getting into in a soon-upcoming post.

For a real world scenario, let’s look at another tree. This one, of the cat. It was one of the first words you learned to spell, so it should be one of the first trees we look at. :-)

Here I use the classic grouping of Kingdom, Phylum, Class, Order, Family, Genus, Species, but the image is very long, you’ll have to open it to full size:

Cat Taxonomy

partial image, click for full

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