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Author Topic:   One evolving species vs speciation.
Taz
Member (Idle past 1396 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 31 of 48 (431013)
10-28-2007 8:35 PM
Reply to: Message 30 by jar
10-28-2007 8:09 PM


Re: Too all. Humans not mosquitos.
If you insist, then I insist that my scenario is pretty much the best one right now. Kill off 90% of the population of Earth. With the remaining 10%, kill off some more. Then split them in 2 groups. Keep them seperate in two entirely different environments for hundreds of thousands of years.

The reason looking to other species is helpful because of our rediculously long lifespan. That's why we study critters that live in a much shorter lifespan, thus giving us more generations in less periods of time.


Disclaimer:

Occasionally, owing to the deficiency of the English language, I have used he/him/his meaning he or she/him or her/his or her in order to avoid awkwardness of style.

He, him, and his are not intended as exclusively masculine pronouns. They may refer to either sex or to both sexes!


This message is a reply to:
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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 32 of 48 (431014)
10-28-2007 8:38 PM
Reply to: Message 31 by Taz
10-28-2007 8:35 PM


Re: Too all. Humans not mosquitos.
If you insist, then I insist that my scenario is pretty much the best one right now. Kill off 90% of the population of Earth. With the remaining 10%, kill off some more. Then split them in 2 groups. Keep them seperate in two entirely different environments for hundreds of thousands of years.

Except your scenario contains no model or mechanism to keep the populations separated.


Aslan is not a Tame Lion
This message is a reply to:
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Fosdick 
Suspended Member (Idle past 3604 days)
Posts: 1793
From: Upper Slobovia
Joined: 12-11-2006


Message 33 of 48 (431019)
10-28-2007 8:48 PM
Reply to: Message 26 by AnswersInGenitals
10-28-2007 7:39 PM


Re: J. Smith: Been there, done that.
AIG writes:

The great theologian Joseph Smith taught that the interior of the earth is hollow and inhabited by a people that live on the inside surface of the earthly shell - and he must be correct since he was told this by an angle of god.. (Apparently, the inner surface people invented Velcro long before we did.) He also taught that there is a hole at the north pole through which we could enter that inner world. Now that the polar ice cap is disappearing, we should be able to enter that world and test if that inner population is reproductively isolated from us outer surface critters. Genetic analysis should determine if and when our two groups separated.


Are you familiar with Thomas Gold's "Deep Hot Biosphere"? It's right up your alley, except Gold is quite serious about thermophilic prokaryotes living in a deep, hot biosphere. His book on that suject is a favorite of mine.

—HM


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Quetzal
Member (Idle past 3976 days)
Posts: 3228
Joined: 01-09-2002


Message 34 of 48 (431028)
10-28-2007 9:18 PM
Reply to: Message 13 by jar
10-28-2007 1:12 PM


Re: on catastrophes
Once again, I'm not convinced that an increase in ionizing radiation is required (i.e., ozone hole). The key, as WK pointed out, is the time frame of the isolating event. I can see the possibility of both phylogenetic speciation (in the event that the species is reduced to a single, viable population for instance), and allopatric speciation as long as the isolating mechanism remains applicable over geological time frames. It just seems easier for me to visualize something like this happening if we moved a portion of our species off to another world.

As you and WK both pointed out, it's a question of time. I agree with WK's speculation that re-acquiring technology from a "stone-age" start point might not take long enough for speciation to occur. Our species seems to have an amazing dispersal ability.


This message is a reply to:
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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 35 of 48 (431033)
10-28-2007 9:35 PM
Reply to: Message 34 by Quetzal
10-28-2007 9:18 PM


Re: on catastrophes
As you and WK both pointed out, it's a question of time. I agree with WK's speculation that re-acquiring technology from a "stone-age" start point might not take long enough for speciation to occur. Our species seems to have an amazing dispersal ability.

Agreed. Re-Acquiring technology would certainly proceed faster than the initial acquisition, unless intentionally limited.

So it looks like realistically, moving off planet will almost certainly lead to speciation simply because unless some major breakthrough is found, the separation will be very longterm. This would be less likely if the expansion was intrasolar, almost assured if it was extrasolar.

Human speciation (into two concurrent species) seems unlikely.

That leaves one possibility, and that is intentional speciation.

How likely is that?


Aslan is not a Tame Lion
This message is a reply to:
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Replies to this message:
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Quetzal
Member (Idle past 3976 days)
Posts: 3228
Joined: 01-09-2002


Message 36 of 48 (431034)
10-28-2007 9:42 PM
Reply to: Message 35 by jar
10-28-2007 9:35 PM


Re: on catastrophes
That leaves one possibility, and that is intentional speciation.

Now THERE'S an interesting speculation. I assume you mean through genetic engineering of some kind? Homo superior has long been a favorite speculation of sci-fi authors. I see no reason why a sort of sympatric speciation based on large scale genetic manipulation wouldn't be possible, as long as the two groups never interbreed - and the "enhanced" group bred true. Of course, you'd need a LOT of manipulation, then some kind of genetic or behavioral isolation for it to work. Kind of an "instant speciation" thing.


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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 37 of 48 (431036)
10-28-2007 9:48 PM
Reply to: Message 36 by Quetzal
10-28-2007 9:42 PM


on design
Now THERE'S an interesting speculation. I assume you mean through genetic engineering of some kind? Homo superior has long been a favorite speculation of sci-fi authors.

Or equally likely. Homo inferior.

I can see three likely scenarios, Wealth, Despot, Religion.

There might be others.


Aslan is not a Tame Lion
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Doddy
Member (Idle past 4014 days)
Posts: 563
From: Brisbane, Australia
Joined: 01-04-2007


Message 38 of 48 (431040)
10-28-2007 10:21 PM
Reply to: Message 36 by Quetzal
10-28-2007 9:42 PM


Re: on catastrophes
Quetzal writes:

I see no reason why a sort of sympatric speciation based on large scale genetic manipulation wouldn't be possible, as long as the two groups never interbreed. Of course, you'd need a LOT of manipulation, then some kind of genetic or behavioral isolation for it to work. Kind of an "instant speciation" thing.

Well, you are right that you would need behavioural modifications. There will be interbreeding between all the various groups of humans, even if genetics prohibits it (technology to the rescue again to pull down the genetic barriers).

So, unless you were very deliberately trying to speciate the human species (something that would probably be very unethical to do), then I can't see it happening.


Help to inform the public - contribute to the EvoWiki today!

This is what we are up against. There are thousands around the world more being (home-)schooled in the same way. But the internet is far reaching! Teach evolution by joining the Evolution Education Wiki today!


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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 39 of 48 (432097)
11-03-2007 7:09 PM


Bump to see is anyone can speciate mankind
One question, even if we should leave earth, what might lead to speciation in an intra-solar colonization scenario?

The only one I have been able to think of would be if once one or more colonies were established, something happened (catastrophe or Chinese Great Withdrawal scenario) on the earth.

Can anyone suggest anything else?


Aslan is not a Tame Lion
Replies to this message:
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bluescat48
Member (Idle past 2294 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 40 of 48 (432135)
11-03-2007 11:48 PM
Reply to: Message 37 by jar
10-28-2007 9:48 PM


Re: on design
Or equally likely. Homo inferior.

or homo insancus or homo absurdius


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EighteenDelta
Inactive Member


Message 41 of 48 (432136)
11-04-2007 12:00 AM
Reply to: Message 39 by jar
11-03-2007 7:09 PM


Re: Bump to see is anyone can speciate mankind
Are you thinking natural speciation or artificial (forced) speciation? How many generations do you think it would take? There was a recent article where another nut jobber was postulating man will split into two groups with in 1200 years I think. The tall attractive intelligent people, where the women are devoid of body hair other than the tops of their heads (I kid you not) and the other group of short stupid hairy people... It boggles the mind to think of how they let these people on any podium to spout this shit. In any case I think it would take fewer generations of forced selective breeding of humans for whatever 'desirable' qualities to speciate than to rely on natural speciation.

For example from wiki...

The best-documented creations of new species in the laboratory were performed in the late 1980s. William Rice and G.W. Salt bred fruit flies, Drosophila melanogaster, using a maze with three different choices such as light/dark and wet/dry. Each generation was placed into the maze, and the groups of flies which came out of two of the eight exits were set apart to breed with each other in their respective groups. After thirty-five generations, the two groups and their offspring would not breed with each other even when doing so was their only opportunity to reproduce.[6]

-x


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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 42 of 48 (432182)
11-04-2007 11:52 AM
Reply to: Message 41 by EighteenDelta
11-04-2007 12:00 AM


Re: Bump to see is anyone can speciate mankind
In the example in Message 39 it would simply be natural speciation.

For example, considering intra-solar colonization, the separation would be on the order of going to a new country during the age of sail. Habitable planets in this solar system are all within a few months travel from each other.

However, for many centuries even if they were self-sufficient, it is unlikely they would have the resources to build space craft independently.

If if something happened on Earth that stopped space travel, either a catastrophe or some political decision as happened in China and led to their Great Withdrawal, is it likely the different human populations in the colonies would remain isolated long enough for speciation to happen?


Aslan is not a Tame Lion
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Franatic25
Junior Member (Idle past 4052 days)
Posts: 30
Joined: 11-08-2007


Message 43 of 48 (432885)
11-08-2007 9:04 PM


Im new here...but would like to add something of what I feel is a good point for this particular debate.

I would consider myself a amateur herpetologist, but my field is mainly boa constrictors...and looking at these I feel would be of SIGNIFICANT value to those interested.

I believe that creatures of all kinds form mutations of the genes during every successive generation...and over an amount of time...those genes may become so different that they would indeed be considered different species. For instance...stingray being related or descended from sharks. These are obviously at this point 2 different animals, biologically, and would not reproduce a "hybrid" if they somehow mated. Apes to Humans could be considered the same...but I will leave that alone.

But onto the matter I wanted to add...the boa constrictor can be found all over Central and South America...and the islands of Central America. By these I mean the boas classified as BC(x) (boa constrictor...x being the individual subspecies).

In this case, I personally believe that the boas of each region developed a particular look and behavior about them that helped in the survival of those areas they inhabit, while still being technically the same species.

I will not list them all, but key differences are as follows.

The boas found in the southern regions of S. America, and in this case I will point out the Argentine Boa...or BCO (boa constrictor occidentalis) have to withstand temperatures of the region...winters being very cold there. How does a boa succeed in survival in this area? Develop darker colors (thereby absorbing more heat) and being girthier (wider...in this case...helpful in having more body area exposed to sunlight...also helping to heat the snake). The BCO are dark brown to black for the most part as adults.

http://i137.photobucket.com/albums/q212/Franatic25/800px-Argentine_Boa.jpg

Further to the North we see several species...but will point out a few. The BCC (boa constrictor constrictor) is the largest of the BC, and inhabits many areas...with subtle changes in looks and length of the animals. Quite beautiful...but biologically, what helps them to survive in their areas? Generally, u can find these in Brazil, Guyana, Peru, Venuzuela, among other insular varieties found in smaller parts of said countries. These boas are very thin bodied looking down at them from above...but on closer inspection, u find that their body shape is rectangular...they are much taller than they are wide...not a round body like u would think a snake should have. How does this help? I would venture a guess that it allows for more surface area vertically, which would aid in doing what boas do best...constrict around their prey. It would allow the snake to be more adept at catching...and killing...larger animals than other boas. But once again, this is my own speculation.

http://i137.photobucket.com/albums/q212/Franatic25/99male2.jpg

Other boa subspecies exist, but will only point out one other...because it is the most interesting...biologically speaking...to me. BCI (boa constrictor imperator) inhabits the greatest area, and is the most successful subspecies. In fact, there are several BCI that have entirely different looks to them, but are considered the SAME subspecies simply because of how close the individual locales are to each other. Columbian BCI being the common boa you will see at petstores. Very large, girthy, animals. But lets consider them the "control" of the BCI.

Going further north, into Central America...we see nothing but BCI...but their differences are distinct. Boa's that inhabit the mainlands of Central America...El Salvador, Nicaragua, Honduras, are all very similar...but smaller than their columbian brothers. But it gets VERY interesting when you consider the Islands varieties of BCI. Here we see survival of the fittest at its best.

The small island (now islands...separated into 2 parts by Hurricane Haittie) of Caulkers Cay isone of the smallest of all BC locales (Tarahumaran Mexican boas being the smallest, but I will leave them alone for now). Their variety being the Caulkers Cay boa (considered BCI). What u will see on Island boas is 2 things...they are smaller than their mainland brothers...but also because of the small population...these boas ALL have their own distinct looks, probably due to the few boas that were on the islands when they seperated from the mainland...or another theory is they drifted their from debris from Belize several thousand years ago. In any case, the point is that since the genetic pool is much smaller, the boas tend to develop differences in color, size, more quickly, by way of the better part of the boa population having a particular gene for size, or color, pattern, etc.
In the case of Caulker's Cay...the boas found there are very nearly all anerythristic (lacking color pigment). They also must avoid the crab population during the turning of the tides...so they are also one of the leanest and arboreal (able to climb trees) of the BC. Less prey on the island (only 5 miles x 1 mile) made the success of the smaller boas more apparent. They thrived on less sustanance, and therefore passed the genes for "small" boas onto their offspring.

http://i137.photobucket.com/albums/q212/Franatic25/Caymale-1.jpg

On the polar end of what u would expect...are the boas of the "Cayos de los Cochinos", or the hog isle boa, also a BCI. These could not be more different. What they have in common with other island boas and the Caulker's Cay boa is size...they are smaller than mainland boas. But the boas that ended up on this island untold time ago, came from Honduras most likely since it is roughly 10 miles from the coast. The slight difference...and the boas on said island that reproduced...passed on interesting traits. They are more naturally hypomelanistic (lacking black color pigment). Now keep in mind that anerythristic and hypomelanistic boas Do occure in other locales...but they are morphs...much like an albino. Whereas the boas of Caulker's Cay and the Hog Isles are NOT morphs...nor do they carry the gene that causes the morph. They simply have a collection of other genes (theoretically) that cause them to look the way they do. In this case, I would venture that the lighter color acts as a way of NOT taking in as much heat as the BCO mentioned earlier. They would instead reflect some of it, like wearing white clothes rather than black. They also have very pronounced color "phases". Being much darker during inactive hours, and brighter when active. The cause of this can be debated...I dont know the reason...but this is a common trait in THIS ONE subspecies (other boas can have phases....but not to the extend I am speaking of with this subspecies)

http://i137.photobucket.com/albums/q212/Franatic25/DSC00076.jpg

So the question is, how do we interpret this information? It cant be disputed that a difference in appearance, among other things controlled by genes, doesnt happen elsewhere. Take the domestic dog...we have several "breeds", but any dog has the potential to produce offspring with any other dog because they are the same species, just having different genetic code causing (in this case, selective bred by people) them to look different.

These boas are like this for much the same reason I feel. Any of the boas Ive mentioned could produce offspring with any other and produce a "hybrid". On the genetic level, they are essentially the same animal.

Now going further back in time though, we can see other boas that could NOT potentially breed with a BC...they have separated genetically enough. A good example...the Dumeril's boa of Madagascar...

Once upon a time the lands of S. America, Africa, and hence (maybe) Madagascar were linked. These boas have had a longer period of time in isolation from there cousins in the americas. The differences being an obvious shift in pattern...BC have "saddles", and spears or cross patterns on the head, and tails of differing color from the body. Not the case in Dumeril's...their tails have the same color and pattern as the rest of the body, and the pattern is quite wild...beautiful. They also have much slower metabolisms, needing roughly half the intake of food as the BC, which in turn causes them to grow slower and reach sexual maturity later (BC being roughly 3 years, Dumeril's roughly 5).

http://i137.photobucket.com/albums/q212/Franatic25/DSC00012.jpg

Other species of boa exist in the SAME locale as the BC boas...but are also not compatible. Everyone knows what an Anaconda is...it is a boa, but not directly related to BC...and Anacondas can get roughly 20 feet...BC's largest subspecies being 8-9 feet, but larger ones do occur...but nothing nearly the size of an anaconda.

Tree boas occur as well. Boas that live their whole lives in trees, and are very adept at climbing, and are much more vividly colored...the largest tree boas subspecies being the Emerald Tree Boa...which is green...u can figure out why. Once again we see that the boas with the better genes for the job passed them on as a direct result of their success.

Going further back, u might want to say that all snakes came from a single species...which may be. But Im not so sure. One of the BIG things that makes a boa a boa...is the fact that they have 2 lungs....other snakes (besides pythons, which have similarities to boas) have only 1. This could mean nothing, or it could mean that boas and pythons possibly developed over time from a completely different animal than any other snake.

So this would beg the question...why would 2 different species develop into something so strange as a legless reptile?

For me this is easy, because I see it every day. If a snake gets loose in my house, he could pass right through my field of vision, and I might not even see him. The body shape is superb for stealth...since they do not have much visual movement for their locomotion...only that we see that they are slowly moving forward. A lizard for example...we would see MUCH more easily...due to the fact that the leg movement would easily give them away.

My boas also have instinctual actions I find intriguing. Before lunging for prey...they will (most of the time) move their head slowly from side to side a few times...like swaying. I thought this to be the snake getting better visual information of how far away the prey is in 3D...the closer the anything is...the more it will move in your vision...while seeing a mountain that is miles away..swaying will do nothing at all...

But then it occured to me that there could be another reason for this. Since the animal is very quick on the draw so to speak...but not quick to chase, camouflage is the best bet. And the swaying could very likely be the snake mimicking a branch in the wind, which would also add to the likelihood of the argument that a snakes appearance, while strange, is a very good tool for an animal to use...the body shape could easily be mistook for a branch or root...which (to me) lends a possible explanation for MORE than 1 animal being the descendents of our current boas and snake.

No boa is poisonous, they instead squeeze the prey and dont allow it to breath, a very successful maneuver...

Other snakes use venom...not very many...but venom is another method that was developed that is very useful.

Make of this information what u will. But to me, I feel that our snakes and boas we see today are descendents of several animals...that now appear to be nearly the same...for the very reason that being that shape and having those skills is useful for the animals success.

And dont mistake the boas and snakes we see today as the "perfected" final form...its still ongoing. We wont see it in our lifetimes, but they will continue to change (like ALL animals) through the years. Not (IMO) because the genes automatically do what is necessary to survive...but rather...that mutations, however small, naturally occur, and they occur for better AND worse...but those mutations that HELP an animal out in some way will more likely be passed on simply due to the animals success at surviving.

Edited by Franatic25, : Edited FACTUAL information of the Caulker's Cay boa.


    
Franatic25
Junior Member (Idle past 4052 days)
Posts: 30
Joined: 11-08-2007


Message 44 of 48 (433040)
11-09-2007 5:18 PM


Rereading my post...I realized that I did not flesh out the evolution of the different species of boa that exist in the SAME area as BC. I will do that now...and to me, this is simple to explain.

The emerald tre boa occurs in the amazon basin...where most prey is NOT found on the ground, but rather in the trees. This to me is a case of divergent evolution. I can only guess why, but at some point, some boas took to the trees and stayed there. Perhaps a predator they were avoiding on the ground...perhaps they had to to catch birds or other animals...but in any case, we see that they have changed drastically from other boas of S. America. What is further interesting about this species is that it could be considered both a result of divergent AND convergent evolution....

Here is a Emeralds...found in the Amazon Basin...
http://i137.photobucket.com/albums/q212/Franatic25/800px-Emerald_Tree_Boa.jpg

On the other side of the world..far removed...is the Green Tree Python....in the rainforests of New Guinea, Indonesia, and surrounding areas. These are the result of 2 difference snakes converging closer to a similar form because they must do very similar things to survive...
http://i137.photobucket.com/albums/q212/Franatic25/714px-Greentreepython.jpg

So what about the anacondas? Well, lets take a look at their habitats...they are frequently found in marshier areas, and rainforests...much like the everglades in Florida or swamps in Louisiana...they hide in as little as a foot of very leafy water...and ambush prey...I am not so sure as to the reason for the appearance of the anaconda now, and how it helps it thrive...obvious biological features that I see are a slicker looking and feeling body...perhaps to fight too much osmosis, or the streamline the snakes swimming...in either case, it is now a completely different species from the BC...
http://i137.photobucket.com/albums/q212/Franatic25/CIMG2545.jpg

Subsequently...we see ANOTHER form of convergent evolution in this case...the reticulated pythons inhabit similar areas...we see the same features that helps the anaconda survive appear again in these pythons...of which are also far removed from each other, these being found in Southeast Asia...but the similarities are striking to me...much like the tree pythons and boas...
http://i137.photobucket.com/albums/q212/Franatic25/IMG_3406.jpg

Of course your could find similar instances all over the animal kindgom...and I could probably talk about a few...but my main field is snakes of the boidae family...and less about pythons...but enough. These are all examples of naturally occuring mutations...which are multiplied by how useful those mutations are to the area of inhabitance...the same could easily be said of any animal...


Replies to this message:
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jar
Member
Posts: 30935
From: Texas!!
Joined: 04-20-2004


Message 45 of 48 (433062)
11-09-2007 7:20 PM
Reply to: Message 44 by Franatic25
11-09-2007 5:18 PM


Topic
This thread is on the issue of whether speciation of humans is likely and under what conditions.


Aslan is not a Tame Lion
This message is a reply to:
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