Two species into one? Are flowerhorns to become a species?

[Juan Artigas]

I read this interesting summary about two species of South American butterflies (Heliconius cydno and H. melpomene) artificially bred under certain circunstances to produce a third species (H. heurippa) which amazingly seems to prefer individuals of its own type for mating, instead of any of the ancient populations.

Does flowerhorns have a chance? After all?

Refer to:

http://www.world-science.net/othernews/060614_hybrid.htm

[michi tobler]

Hi Juan,

apparently hybrid speciation is probably more common that people thought. A very interesting article by Ole Seehausen in TREE (2004) reviews the subject. Recently discovered species of hybrid origin that are known to hobbyist are for example N. buescheri from Lake Tanganjika or the Swordtail X. clemenciae.

I doubt that we should go so far and call Flowerhorns a distinct species. Most importantly we don't know if they are reproductively isolated from the parental species. My guess: probably not...

Cheers, M

[Dan Woodland]

What is the definition of a species?

Look here:

http://www.google.com/search?hl=en&lr=&defl=en&q=define:species&sa=X&oi=glossary_definition&ct=title

Do species have to produce viable offspring? Case in point, it's contested that the Blue Dempsey does not breed true and is virtually un-breedable...

What other parameters should be considered?

Dan

[Juan Artigas]

There are several species concepts, we are referring here to the biological species concept, which is reproductively isolated. We know that in some species concepts this is not a must.

I was thinking about Michi's post and I was shock to learn about Xiphophorus clemenciae could be a case of hybrid speciation. That is amazing, would you give me the full reference? Do you have the paper?

[Philippe Burnel]

I'd like to get the paper about buesheri beeig an hybrid.... !

It seems that Nl marunguensis is an hybrid but I don't think so for buesheri

[michi tobler]

Hi Juan and Philippe,

Meyer, A., W. Salzburger, and M. Schartl. 2006. Sexual selection driven hybrid origin of a new species of swordtail (Xiphophorus clemenciae, Pisces). Molecular Ecology 15: 721-730.

http://www.evolutionsbiologie.uni-konst ... 05de85721c

Stupid as I am I mixed up the species name for the Neolamprologus (those Africans remain a mystery for me anyway). Of course, Philippe is right.

Salzburger W., Baric S. & Sturmbauer C. (2002) Speciation via introgressive hybridization in East African cichlids? Molecular Ecology, 11, 619-625.


I just want to mention at the end that reproductive isolation in the biological species concept does not mean that two separate species cannot produce viable hybrids! Reproductive isolation may be maintained in a natural situation by prezygotic barriers (e.g. sexual selection).

cheers, m

[Juan Artigas]

Thanks Michi, it is very interesting.

[Michael.NEGRINI]

Hello,

one more interesting paper :
http://www.frontiersinzoology.com/content/pdf/1742-9994-1-5.pdf

[Tachymarptis]

Even in mammals you may find such cases, as with the american red wolf, which may be a hybrid between the gray wolf and the coyote. Speciation is often far from being the "clean" monophyletic process usually depicted.

[Lisachromis]

Using that red wolf example you gave, I watched an episode about Red Wolves up north in Ontario and that because of their small numbers they were breeding with the coyotes since they were getting hunted. The guy doing the study said that 1/5 of his study animals were killed (hunted) in one year alone. That doesn't bode well at all to me. It may be that the red wolves elsewhere are doing the same thing and that there may not be all that many pure red wolves anywhere.

[Tachymarptis]

The same problem exists with the very beautiful abyssinian wolf (or abyssinian jackal). Under a certain amount of individuals, hybridation with other canids (jackals or wild dogs) becomes the major threat. A captive breeding program becomes the best way for avoiding genes dilution.

[Marco Arroyo]

hi there, yes indeed its very interesting the situation, refer to the born of a new species from an hybridization, i found something from the Xiphophorus clemencie that Michi refer, and that goes like this:

Hybrid origin of a swordtail species (Teleostei: Xiphophorus clemenciae) driven by sexual selection
AXEL MEYER*, WALTER SALZBURGER* and MANFRED SCHARTL†

Abstract

The swordlike exaggerated caudal fin extensions of male swordtails are conspicuous traits that are selected for through female choice. Swords are one of only few examples where the hypothesis of a pre-existing bias is believed to apply for the evolution of a male trait. Previous laboratory experiments demonstrated that females prefer males with longer swords and even females from some swordless species show an affiliation for males of sworded species. Earlier phylogenetic studies based on maternally inherited mitochondrial DNA placed the sworded southern swordtail Xiphophorus clemenciae with swordless platies, contradicting its morphology-based evolutionary affinities. The analyses of new nuclear DNA markers now recover its traditional phylogenetic placement with other southern swordtails, suggesting that this species was formed by an ancient hybridization event. We propose that sexual selection through female choice was the likely process of hybrid speciation, by mating of platy females with males of an ancestral swordtail lineage. In artificial crosses of descendent species from the two potential ancestral lineages of X. clemenciae the hybrid and backcross males have swords of intermediate lengths. Additionally, mate choice experiments demonstrate that hybrid females prefer sworded males. These experimental lines of evidence make hybridization through xeno-specific sexual selection by female choice the likely mechanism of speciation.

[Tom Lorenz]

Great stuff. I think even Darwin himself believed that species were a very 'plastic' concept. Natural hybridization is a very interesting phenomena that is good at giving headaches!