Mugwump's Fish World

THE POND-THE FRESHWATER PLACE => Cichlids => Topic started by: BillT on September 20, 2013, 03:48:35 PM

Title: Deep Evolutionary History of Cichlids
Post by: BillT on September 20, 2013, 03:48:35 PM
Here is a link to a little news article about how cichlids got to all their current sites.
Hopefully you will be able to get to it. Not sure if i have some automated password set-up for this site.

http://news.sciencemag.org/biology/2013/09/tracing-cichlids-through-seas (http://news.sciencemag.org/biology/2013/09/tracing-cichlids-through-seas)

Anyway the take home is that cichlids evolved about 57-65 million years ago. The gondwana landmass broke up about 135 million years ago, so that could not explain cichlids in the landmasses that resulted from that break-up (Africa, India, S. America).
They postulate that early cichlids swam the narrow S.  Atlantic (perhaps in a plume of freshwater from the Amazon in the than narrow S. Atlantic).

Another possibility would be birds moving viable fish eggs from one place to another, something documented by Darwin for other species.

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Here is a movie of continental drift:
http://www.tectonics.caltech.edu/outreach/animations/anim_pangaea/Resources/anim_pangaea.mov (http://www.tectonics.caltech.edu/outreach/animations/anim_pangaea/Resources/anim_pangaea.mov)

Here is another:
http://www.scotese.com/satlanim.htm (http://www.scotese.com/satlanim.htm)
The garish colors in the oceans represent the areas of seafloor that formed at the same time and would therefore have magnetic properties imposed upon them by the earth's magnetic field (which flips from time to time) at the time the rocks solidified.

This movie has no scientific basis:
http://en.wikipedia.org/wiki/Ice_Age:_Continental_Drift (http://en.wikipedia.org/wiki/Ice_Age:_Continental_Drift)
Title: Re: Deep Evolutionary History of Cichlids
Post by: PaulineMi on September 20, 2013, 05:42:21 PM
The article opened...no problem.  Thanks for sharing it.

Cichlids are interesting in that they're found in hard water, soft water, brackish water, are Old World and New World fish. There are so many different types of spawning behaviors in addition to overall appearance differences. This article confirms that there are still many mysteries that surround this species.
Title: Re: Deep Evolutionary History of Cichlids
Post by: ilroost on September 20, 2013, 06:52:37 PM
Thanks for the article. It's right up my alley as to what i love to keep. Great reading
Title: Re: Deep Evolutionary History of Cichlids
Post by: Mugwump on September 20, 2013, 06:57:46 PM
I agree, really interesting link...thank you...
Title: Re: Deep Evolutionary History of Cichlids
Post by: BillT on September 21, 2013, 01:41:10 AM
Here's a link to a podcast talking about this.
https://itunes.apple.com/us/podcast/science-podcast-cambrian-explosion/id120329020?i=168158773&mt=2 (https://itunes.apple.com/us/podcast/science-podcast-cambrian-explosion/id120329020?i=168158773&mt=2)
This is a science-of-the-week podcast. The cichlid stuff starts at about 30 minutes.

The rest is good too. I like the part about the Cambrian explosion. This is when the basic animal forms were first evolved. Much earlier than the differences between us and fish.