Math and evolution

[wb3]

I was in geometry today when I thought of something concerning speciation. Speciation is the mechanism by which evolution takes place. The change that takes place in species, however, does not occur. It is like the communitive and associative properties of multiplication. Look here:

1*2*3=6
1(2*3)=6
1(3*2)=6
(2*3)1=6
(3*2)1=6
2(1*3)=6
2(3*1)=6
(3*1)2=6
(1*3)2=6
3(2*1)=6
3(1*2)=6
(2*1)3=6
(1*2)3=6

All these say the same thing. They just look a little different. Same thing with "closely related" species, they look different but are interchangeable.

 

[troodon]

Today at 03:01 PM wb3 said this in Post #1
1*2*3=6
1(2*3)=6
1(3*2)=6
(2*3)1=6
(3*2)1=6
2(1*3)=6
2(3*1)=6
(3*1)2=6
(1*3)2=6
3(2*3)=6
3(3*2)=6
(2*3)3=6
(3*2)3=6 

The last four equal eighteen. Different species I guess?

 

[wb3]

A technical oversight which is now corrected.

 

[Freodin]

Today at 12:01 AM wb3 said this in Post #1

I was in geometry today when I thought of something concerning speciation. Speciation is the mechanism by which evolution takes place. The change that takes place in species, however, does not occur. It is like the communitive and associative properties of multiplication. Look here:

1*2*3=6
1(2*3)=6
1(3*2)=6
(2*3)1=6
(3*2)1=6
2(1*3)=6
2(3*1)=6
(3*1)2=6
(1*3)2=6
3(2*1)=6
3(1*2)=6
(2*1)3=6
(1*2)3=6

All these say the same thing. They just look a little different. Same thing with "closely related" species, they look different but are interchangeable.

Beyond the mistake with the last four lines, you are basically correct. On the level of DNA all species can be shown to be (more or less) closely related.

 

[Freodin]

And by your mistake, you have also shown one of the mechanisms by which speciation works: mistakes. Mutations, copying errors.

 

[wb3]

My biology teacher even admits that that was not a good explanation for how multicellular organisms "arose" from unicellular. I can believe mutatons among single celled organisms, it happens of course.

 

[anon5354]

It is not a comprehensive explanation, but a relatively good explanation compared with others.

 

[lucaspa]

Today at 06:01 PM wb3 said this in Post #1

All these say the same thing. They just look a little different. Same thing with "closely related" species, they look different but are interchangeable.

I'm afraid closely related species are not interchangeable, anymore than you are interchangeable with your sibling (unless you are identical twins). The definition of species for a sexually reproducing population is:  groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups. (Mahr 1942).

That is, each species represents separated gene pools that do not combine with other gene pools.

Now, of course two closely related species are gong to be similar.  As Darwin said: "nature does not take leaps".  But the differences are cumulative.  Think of this as a number line of positive integers. 1 is very close to two.  Call that a speciation.  Now, when 2 speciates to 3, 3 is a little farther from 1.  Continue that for 7 more speciation events and now 10 is a long ways from 1 on the number line.

 

[lucaspa]

Today at 06:19 PM wb3 said this in Post #6

My biology teacher even admits that that was not a good explanation for how multicellular organisms "arose" from unicellular. I can believe mutatons among single celled organisms, it happens of course.

I'm afraid your biology teacher is not as informed as he or she might be.  Understandable. But unfortunate in this case as it has given you the mistaken idea there is a "gap" here.

We can look at organisms today that are between unicellular and multicellular.  One of these is the amoeba Amoeba Dictyostelium. Most of the time this amoeba is single celled, but forms multicelled organism with differentiation when food supplies are low.  Sexually reproduces sometimes, forms a cyst, and then asexually divides with the new genetic material.  Also forms an eye of sorts from individual cells that act as lenses.  Cells act and use same proteins as phagocytes in immune system.  1.  C Zimmer, The slime alternative.  Discover 19: 86-93, 1998 (Sept)

So here we have a living organism that goes back and forth from single celled to multicelled.

Now, if you really want to get into this some more, go read 2.  DL Kirk Molecular-Genetic Origins of Multicellularity and Cellular Differentiation.  Reviewed by G Bell in Development: Volvox. Science 282: 248, Oct. 9, 1998. 

Volvox (an algae) is a model system of multicellularity.  Has fewer than 20 cells and only two types: soma and germ cells.  Has single celled relatives, notably Chlamydomonas.

 

[wb3]

Sorry. Ameoba are prokaryotes that have nothing to do with us according to a phylogenetic tree. Secondly that is a colonial organism not multicellular. There is a pretty big difference.

 

[euphoric]

Today at 10:54 PM wb3 said this in Post #10

Sorry. Ameoba are prokaryotes that have nothing to do with us according to a phylogenetic tree. Secondly that is a colonial organism not multicellular. There is a pretty big difference.

I believe amoeba are actually eukaryotic. 

I also believe that lucaspa's point was that Dictyostelium provides insight into the possible method by which multicellular organisms might have formed from unicellular organisms.

-brett

 

[webboffin]

Burn the books!!!!!

 

[Taffsadar]

Yesterday at 10:54 PM wb3 said this in Post #10

Sorry. Ameoba are prokaryotes that have nothing to do with us according to a phylogenetic tree. Secondly that is a colonial organism not multicellular. There is a pretty big difference.

They are still organism containing more than one cell and thats not a long way from multicellular organism if you ask a decent teacher.

 

[lucaspa]

Yesterday at 05:54 PM wb3 said this in Post #10

Sorry. Ameoba are prokaryotes that have nothing to do with us according to a phylogenetic tree. Secondly that is a colonial organism not multicellular. There is a pretty big difference.

Amoeba are eukaryotes.  They have a nucleus.  And no, it's not "colonial". Didn't you see that it developed specific tissues? Particularly the eye? That makes it multicellular.

Please read more carefully before you dismiss.

 

[lucaspa]

Yesterday at 06:48 PM euphoric said this in Post #11




I believe amoeba are actually eukaryotic. 

I also believe that lucaspa's point was that Dictyostelium provides insight into the possible method by which multicellular organisms might have formed from unicellular organisms.

-brett

EXACTLY! The question was how multicellularity arose. And Dictyostelium offers an intermediate in that pathway.  Both unicellular and multicellular.

Also offers an intermediate in the evolution of sexual reproduction, since it reproduces asexually sometimes and sexually sometimes.