Researchers Catch Lake Victoria Fish in the Act of Evolving

[Kula]

Pretty nifty read here:

http://blogs.discovermagazine.com/80beats/2008/10/01/researchers-catch-lake-victoria-fish-in-the-act-of-evolving/

[gm72]

Super cool news, thanks for sharing!

[Gayle]

That is pretty interesting!

[Red]

thats awesome!

[Fishguy2727]

ALL species are in the act of evolving. This is not a start and stop procedure. This is part of the reason why so many people have a problem understanding it and why so many do not want it taught in schools. Popular articles like this give a very bad impression to those who do not fully understand evolution.

All of the species that interbreed successfully to produce fertile offspring are an example of this. For example: all the mbunas are apparently so closely related and have yet to FULLY speciate. This is why they can all interbreed so easily. We find examples of this all over the animal and plant kingdoms. Even though almost all have been recognized as distinct species, new advances in biology are demonstrating why current ideas about what a species really is and which are truly distinct species and which are actually populations and subspecies are all flawed.

The classic method of speciation involves some genetic isolation, usually in the form of geographic isolation. A single species and population are split. The two new populations have slightly different gene pools and undergo mutations independent of each other. Different selective pressures result in the two populations becoming more and more different. IF they are different enough and far enough along in this process when and if they ever become a single population again, they are different species. IF this process is not complete and they are different but not different enough (they can still interbreed to produce fertile offspring) then they are just populations or subspecies.

People have a tendency to think that evolution is done, especially when they think that humans are the pinnacle of evolution. It is always in action. It always will be. It is never done.

I am in no way trying to be mean to the thread starter, it is a very interesting article and thank you for sharing. I just do not like it when popular articles like this further twist the idea of evolution to an already very confused public.

[Kula]

ALL species are in the act of evolving. This is not a start and stop procedure. This is part of the reason why so many people have a problem understanding it and why so many do not want it taught in schools. Popular articles like this give a very bad impression to those who do not fully understand evolution.

All of the species that interbreed successfully to produce fertile offspring are an example of this. For example: all the mbunas are apparently so closely related and have yet to FULLY speciate. This is why they can all interbreed so easily. We find examples of this all over the animal and plant kingdoms. Even though almost all have been recognized as distinct species, new advances in biology are demonstrating why current ideas about what a species really is and which are truly distinct species and which are actually populations and subspecies are all flawed.

The classic method of speciation involves some genetic isolation, usually in the form of geographic isolation. A single species and population are split. The two new populations have slightly different gene pools and undergo mutations independent of each other. Different selective pressures result in the two populations becoming more and more different. IF they are different enough and far enough along in this process when and if they ever become a single population again, they are different species. IF this process is not complete and they are different but not different enough (they can still interbreed to produce fertile offspring) then they are just populations or subspecies.

People have a tendency to think that evolution is done, especially when they think that humans are the pinnacle of evolution. It is always in action. It always will be. It is never done.

I am in no way trying to be mean to the thread starter, it is a very interesting article and thank you for sharing. I just do not like it when popular articles like this further twist the idea of evolution to an already very confused public.

I have no clue how this article twists the idea of evolution. I think it's a great article that demonstrates the process of evolution - and is especially good because it provides visual documentation to people who don't believe in evolution. I really don't know how somebody not living in a third world country could believe evolution doesn't exist.

[kaybee]

ALL species are in the act of evolving. This is not a start and stop procedure....People have a tendency to think that evolution is done, especially when they think that humans are the pinnacle of evolution. It is always in action. It always will be. It is never done.

Agreed.

It takes an extremely long succession of generations for even minor evolutionary changes to occur. While the article states "the two diverging populations are rapidly accumulating genetic differences" it doesn't put anything into perspective.

For example how rapid is 'rapidly'. Is this indication of 'a population in the act of splitting into two distinct species' something that has been on going for thousands of years and will continue to take millenia, or is this something new which wasn't seen in the last few decades?

Also isn't it possible the species in the article is just an example of the development of a variant morph rather than the development of a new species? Look how many different morphs of p. elongatus, c. afra and tropheus moorii there are (yet are catergorized as being the same species, respectively).


...all the mbunas are apparently so closely related and have yet to FULLY speciate...this is why they can all interbreed so easily.

Does being closely related and able to interbreed equate to having not fully speciated? Mbuna's, haps and peacocks can all be crossed and produce viable and fertile progeny. Would that mean that a Nimbochromis venustus hasn't yet fully speciated from metriaclima lombardoi?


...IF this process is not complete and they are different but not different enough (they can still interbreed to produce fertile offspring) then they are just populations or subspecies.

How would this concept apply to the Great Cats (Genus Panthera)?

There's no question the great cats, while members of the same genus, are separate species, yet female hybrid Panthera progeny are generally fertile.

[Fishguy2727]

The worst part of the article is the title. It makes it sound like two fish were trying to evolve real quick in the back corner without anyone noticing. The article requires people to not fully understand evolution. The article itself was not bad, but titles like that really throw some people off.

Coloration is one of the easiest things to change, and is usually the first. This is demonstrated best by domesticated animals. In most cases the first changes from the natural form are color, not fins or feathers, not size or shape, coloration.

The eye adaptations discussed in this article could even be an acclimation, not an adaptation. This means the red and blue sensing cells could be there or not (or disproportional) because they being used more or less, not necessarily genetically determined. I would have to read the original scientific article to see if they determined if this was actually genetic and not just acclimation.

Yes, in fact by one of the main methods of defining and determining a species, if they can interbreed to produce fertile offspring then they are actually the same species. It is called the biological species concept. It is one of the two or three most commonly used methods to define/determine a species. This was discussed in the article I wrote entitled 'hybrids are not inherently wrong'. This can be found in my blog. In respect to the cichlids of Lake Malawi, yes, it does mean that if they can interbreed they are only most of the way through this process and not truly completely speciated. However, for practical purposes and since no one species concept is accepted as THE right one or anything like that, it does not mean they will be rewriting and reclassifying all the species.

In reference to the large cats, again yes, if the offspring are fertile they are the same species. However, I doubt they would count it as fertile if only one gender was, as in your example or in a more familiar example, parrot cichlids.

In recent news a hunter shot a grizzly/polar bear hybrid. It was dead so it is hard to determine if it was fertile, but based on how closely the two species are related genetically (another method of defining/determing species) polar bears should actually be classified as a subspecies of grizzlies. Most likely the entire population of polar bears will simply 'melt' in to populations of grizzlies as the habitat for polar bears is lost. As the polars are pushed farther south and into the habitat of grizzlies they will begin to interact even more. This could easily result in many hybrids and it would not surprise me if in twenty years visitors to Alaska and the like would be spotting grizzlies and grizzly/polar hybrids as a normal, or at least not rare, thing.

On a side note, the people who do not believe in evolution will still stand firm, confident that they are still 'both just fish'.