Fuzzy Logic and the Definition of Species

The definition of "species" is a confusing and nebulous one. Creationists have the wrong idea about it--and so do many other people. This video uses the Computer Science concept of "Fuzzy Logic" to illustrate a better way of thinking about them.

[jebuskryst]

Wonderful video. One of the best explanations of transitional fossils I have ever seen.

[shanedk]

"And I really don't see where genetics demands a theory of evolution"

Regardless of origin, many things like genetic similarity, atavisms, ERV sequences, etc. make NO SENSE WHATSOEVER except in the light of evolution.

[blakecarterpiano]

Over ten years later, this video is needed more than ever.

[shanedk]

"Biology existed as a science well before evolution"

Yes, and they kept getting most things wrong.

[christo]

Excellent video. The biggest problem people have is with the time scales. Lots of small changes lead to big changes but only when directly contrasting 2 animals separated by thousands of generations. You don't get any of these big changes when looking at a small window in time, so a dog is still a dog is still a dog. But they are looking at nothing but modern dogs.

[ProcInc]

"Personally, whichever way is fine with me; I just wanted to give people a different way of thinking about it. "

Yes exactly, what you were doing is using terms that don't confuse the issue as I did.

[shanedk]

@Wanda7771 "That's what Darwin did"

No, NEVER. You're correct that Haeckel did, but nothing in evolutionary theory depends on Haeckel.

[shanedk]

From the BLS's latest report on unemployment:

"Employment fell in construction and in transportation and warehousing, while temporary help services and retail trade added jobs."

So, lasting jobs in production are NOT being created.

[Maelwysii]

I wish I'd found this video years ago; instead it took me months of working it through in my head. The whole point is that there is no such thing as a 'species', and once you get that, it makes evolution make so much more sense. Nice work. :)

[shanedk]

And yes, it's happened in humans: when our ancestors started milking cattle, everyone was lactose intolerant. In everywhere but northern Europe, milk was used to make lactose-free cheese, but there they started drinking it unprocessed. As a result, a genetic mutation that occurred about 7500 years ago got selected for; the more northern European ancestry you have, the less likely you are to be lactose intolerant. Same thing if you're Asian: the more Mongolian heritage, the less intolerance.

[shanedk]

Also:

"The number of long-term unemployed (those jobless for 27 weeks and over) continued to trend up in January, reaching 6.3 million. Since the start of the recession in December 2007, the number of long-term unemployed has risen by 5.0 million."

"In January, the civilian labor force participation rate was little changed at 64.7 percent."

Hardly a rosy picture!

[shanedk]

"there is no such thing as a half-way fish and half-way tetropod"

And that's not what the fuzzy logic says. The fuzzy logic says that Tiktaalik has equal membership in both groups: not fully belonging to either one, but equally at home both places.

This doesn't say ANYTHING about the fossil itself, only it's category. It's not a crocoduck.

[shanedk]

Yes, I double-checked from my picture source: Science Friday, May 23rd, 2008:

"Researchers from the University of Melbourne in Australia and the University of Texas extracted DNA from preserved samples of the now-extinct Tasmanian tiger (Thylacinus cynocephalus) and mixed it into a living organism. The genetic hybrid is mostly mouse: it contains only one Tasmanian tiger gene--Col2A1, which codes for skeleton formation."

[AlmightyAtheismo]

Darwin published Origin on the 24th of November 1859.
Mendel published his paper in 1866 in the publication "Proceedings of the Natural History Society of Brünn".

Even though it wouldn't be until the early 20th century when the value of Mendel's work was truly realized, I'd still continue to consider them contemporaries.

[jcantlie]

Very clearly explained - nice! I'm glad this is out there; I'll be linking this to creationists (expect apoplectic posts).

PS - the elevator music is quite charming.

[shanedk]

@Wanda7771 "Why should there be ANY stasis in millions of years?"

If you're in a relatively unchanged niche, what would be there to drive evolution?

"Ceolocanths are not EXACTLY the same? But there still ceolocanths, right?"

Coelacanthiformes is an ORDER. There are entire FAMILIES of Coelocanths, each containing their own genera and species. Saying they're "still coelocanths" is like saying they're "still carnivores."

[shanedk]

He's referring to the fact that every species branches off from its part of the tree. So birds are dinosaurs in the same way that they're vertebrates.

So, I guess by that logic, all the birds and transitionals should still have 1 in the dinosaur set, instead of grading down to 0.

Personally, whichever way is fine with me; I just wanted to give people a different way of thinking about it.

[shanedk]

True, but there are also a lot of benefits in seeing how far things deviate from a straight line, and that can be beneficial. Fuzzy sets can definitely help at times like that.

[shanedk]

@vrod000 "what is the definition of species?"

Species is a taxonomic group whose members can produce fertile offspring under natural conditions. I gave the definition in the video.

"Correct me if I am wrong, but isn't a mule the offspring of a horse and a donkey?"

Yes, but it's infertile, so horses and donkeys aren't the same species.

[Minttzz]

I often use the colour wheel (or RGB values) when arguing about changing from one species to another in the fossil record. You can give colours labels and say somewhere between blue and green is teal, but trying to put borders on where teal begins and ends is a matter of opinion.