Feeds:
Posts
Comments

Posts Tagged ‘giraffe’

Because I’m a prick, that’s why.

i don't always eat giraffe

marius sacrifice

 

Denmark Zoo Kills Giraffe

 

hyenas eat giraffe

 

free rye bread!

Marius the giraffe

You can use the memes as you’d like.

But you might just be going to hell with me!

 

Read Full Post »

Let me ask you a very simple question:

How many species of giraffe are there?

I bet the vast majority of you would say:  “Just one.”

A few might point out that next closest relative to the giraffe is the okapi, which looks like something created in gene splicing lab, and a few others might mention that most taxonomists believe the pronghorn is a close relative of the giraffe and the okapi.

But I bet that very few of you would say that there are multiple species of giraffe– unless you’ve seen this study.

Yeah. It turns out that when we examine the mtDNA and certain microsatellite markers, there are likely several species of giraffe.

But we have historically believed that there is just one species.

But this study found that there are 11 genetically distinct populations of giraffe, but six of these are fairly close to being separate species– and might very well be. (This same methodology found that there were two species of clouded leopard and two species of elephant in Africa that are quite genetically distinct from each other.)

These six populations had virtually no evidence of interbreeding. Masai giraffes, reticulated, and Rothschild’s giraffes live in roughly the same area, but they are reproductively isolated from each other.

Further, as much as 1.5 million years of evolution may be separating them.

Now, more genetic studies need to be performed on giraffes. These types of studies can be in error, but if we look at more of the genome and have more samples in the studies, we will get a better understanding of how giraffes evolved.

The evidence is pretty good that the classical classification of only a single species of giraffe might very well be in error.

This study raises some important questions for how we approach taxonomy.

Some people really like to split up related populations into species, even if we have lots of evidence of a gene flow between populations. These people are called “splitters.”

Others prefer to group related populations together within a single species, especially if there is evidence of a considerable gene flow between them. These people are called “lumpers.”

Historically, it was to a naturalist or explorer’s advantage to define something as a new species.

I have never been able to keep track of all the potential bear species that have been cataloged. Most of these fit nicely into the brown bear species, but in the nineteenth century, any number of bears could be deemed a unique species solely on the vanity and caprice of the person documenting them.

Now, we have a whole host of tools to help us see how species are related.

Traditionally, morphology was used to determine taxonomy and phylogenetic relationships, but now we are using various assays of DNA to make these judgments.

We’ve seen the validity of some potential species collapse under these analyses,  the red wolf and the Eastern wolf are two that have fallen, as has the golden moon bear of Southeast Asia. A gold-colored phase of the Asiatic black bear (“moon bear”) was proposed as a new species, but it was found to be nothing more than a golden Asiatic black bear.

We’ve also seen the validity of certain species confirmed, like the kouprey of Cambodia, which was once claimed to be nothing more than a hybrid between banteng and an indicus cattle.  A mitochondrial DNA study found that kouprey and Cambodian banteng had very similar mtDNA— which led to this particular speculation.  But a study that included a larger sample of banteng mtDNA and as well as some nuclear DNA markers revealed that at least one kouprey cow wound up intermixing with the banteng in Cambodia during the Pleistocene. Virtually all banteng from Cambodia have kouprey mtDNA.

What’s particularly interesting is the researchers who were claiming that the kouprey was hybrid dropped the nonsense almost instantly after being shown what the nuclear DNA studies revealed.  That’s how science is supposed to work. If a hypothesis is falsified, you’re supposed to accept it as being in error and not true.

For the proposed red and Eastern wolf species, researchers and people who should generally know better keep promoting both of them and also entertain denial that the genome-wide analysis that was performed on wolves and coyotes found anything uself– which was more extensive than any of these other studies that have proven very useful in determining species status.

There is more evidence that there are multiple species of giraffe in Africa than there is evidence of multiple species of wolf in North America, yet the taxonomy of giraffes has not been changed in any official capacity. And the same goes for the several species of wolf in North America.  A wolf with some coyote ancestry is called a unique species of Eastern wolf, even though its mate is a pure wolf, but a Rothschild’s giraffe and a masai giraffe are the same species, even if they will not mate with each other at all.

How weird is that!

 

 

 

Read Full Post »

Very informative!

Source.

Giraffes are not values voters.

I can tell you that!

Read Full Post »

Here’s the clip I mentioned yesterday:

Source.

 

Read Full Post »

Source.

Part 2. (on Youtube, where you can find the rest)

The size and position of recurrent (inferior) laryngeal nerve is the death knell for ID.

I’m sorry.

Our is similarly positioned (and poorly “designed”), but ours isn’t redirected 15 feet as it is in the giraffe.

Read Full Post »

%d bloggers like this: