Mulitregional vs Out of Africa

[Minimalist]

Here....let it load, takes a while.

[Digit]

Am I heck RW! I'm learning, Monk is the expert and always, I find, willing to help.
Here's the animation link for you.

http://www.classzone.com/books/earth_sc ... ualization

Just click on it and follow the instructions. It shows that the southern tip of SA and the northern part of antarctica remained in close proximity even when the two other continents were some distance apart.

[Forum Monk]

The Fundies (well...maybe not all of them but Arch) thinks Pangea is a plot to discredit the bible.

Yeah, they thought it up at one of their frequent club meetings.

Smoking cigars in the sauna, one said, "ya know them fundies are really starting to impact my research funds. We need a way to stop those guys, you know, discredit them."
"I got an idea! What if the continents were one big super continent..."

Later another said, "You know them preClovis folk are really starting to crank me off..."

[ravenwing5910]

Thanks for the link Digit. Still at 30mya that would have been quite a trip to get from Africa to SA, even if the debris had plenty of food and fresh water stuck on it with the monkeys.

Min, is there a link to your animation?

[Digit]

But did you note the proximity of antarctica to both continents RW? That's as near a land bridge as makes no difference and much more survivable in terms of time than across the Atlantic.

[Minimalist]

Thanks for the link Digit. Still at 30mya that would have been quite a trip to get from Africa to SA, even if the debris had plenty of food and fresh water stuck on it with the monkeys.

Min, is there a link to your animation?

http://serc.carleton.edu/images/NAGTWor ... angea2.gif


They had some other stuff on the page, too.

[Forum Monk]

While those small animations present a rough idea of the theory there is a lot of detail left out. I too have some questions:

• 1. What caused this sudden breakup?
  2. How long did it take for the continents to reach their approximate positions today?
  3. What kind of catastrophic conditions were going out simultaneously, i.e earthquakes, eruptions, tsunamis, nuclear winter, etc.?
  4. What was the effect on living things?
  
  

[Beagle]

Digit, some time ago I was checking out this question. I looked at 3-4 abstracts on the genetics and never saw a split at 30 million ya. Where did you see that?

After looking at the images (they're great), there is still no continuous land mass at 30Mya. The mystery remains.

[ravenwing5910]

While those small animations present a rough idea of the theory there is a lot of detail left out. I too have some questions:

• 1. What caused this sudden breakup?
  2. How long did it take for the continents to reach their approximate positions today?
  3. What kind of catastrophic conditions were going out simultaneously, i.e earthquakes, eruptions, tsunamis, nuclear winter, etc.?
  4. What was the effect on living things?
  
  

Excellent questions Monk! I want to know all that too!

[Minimalist]

1. http://pubs.usgs.gov/gip/dynamic/Pangaea.html

In recent years, the study of terranes (called "terrane tectonics" or "terrane analysis") has become a specialized field within plate-tectonics research. Such studies suggest that plate tectonics has been operating in some fashion since very early in the Earth's history, perhaps as early as 3.8 billion years ago. An intriguing, but sketchy, picture seems to be emerging: There have been several cycles of supercontinent formation, each followed by break-up and subsequent drifting of the fragmented parts. Pangaea itself may have been formed by the aggregation of separate continents that drifted back together after the break-up of an older supercontinent that existed about 550 million years ago.

2. 225 million years.

3. Why would a rate of 2.5 centimeters per year result in catastrophic events? The same rate is evident today.

http://pubs.usgs.gov/gip/dynamic/understanding.html

Perhaps the best known of the divergent boundaries is the Mid-Atlantic Ridge. This submerged mountain range, which extends from the Arctic Ocean to beyond the southern tip of Africa, is but one segment of the global mid-ocean ridge system that encircles the Earth. The rate of spreading along the Mid-Atlantic Ridge averages about 2.5 centimeters per year (cm/yr), or 25 km in a million years. This rate may seem slow by human standards, but because this process has been going on for millions of years, it has resulted in plate movement of thousands of kilometers. Seafloor spreading over the past 100 to 200 million years has caused the Atlantic Ocean to grow from a tiny inlet of water between the continents of Europe, Africa, and the Americas into the vast ocean that exists today.

4. Occasionally an earthquake kills a bunch of people. We seem to deal with it.

[Forum Monk]

I dunno, Min, 2.5 centimeters seems like a lot to me. Thats six feet in the life time of an average man. It would be noticable and require some of our ground based telescopes to be realigned very frequently. Older instruments would have lost their polar alignments by now.

[ravenwing5910]

Thanks Min.

I float around USGS pages all the time, I wonder why I haven't come across these pages before?

[Minimalist]

I dunno, Min, 2.5 centimeters seems like a lot to me. Thats six feet in the life time of an average man. It would be noticable and require some of our ground based telescopes to be realigned very frequently. Older instruments would have lost their polar alignments by now.

I just find 'em and paste 'em, Monk.

[Digit]

http://www-personal.umich.edu/~phyl/anthro/platy.html
Here your are Beag, took me some time to find a link I'm afraid.
No there was no land link as far as I know, I simply pointed out that the most survivable route was via antarctica.
Many monkeys need little water, obtaining their moisture from fruit, and moisture would be the major problem across the atlantic, but if the circumpolar currents were in the correct direction, (perhaps Monk could help on this) the journey would be entirely reasonable, and at the end of the day, they got there some how.

[Digit]

Your questions have puzzled me for many years Monk. As an engineer you will be fully aware that any spinning object will attempt to establish an equilibrium, and a globe with a massive out of balance mass on the one side is certainly going to be under stress.
The usual reason given for the land mass to break up seems to be volcanic plumes that rose and forced the mass apart, but logic would seem to suggest that as the crust is thinner under ocean depths most activity would have been on the other side of the planet.
My own opinion is that out of balance forces probably contributed to the breaking apart.
Another point is have the continents moved at a steady pace? Again I think not. If out of balance forces were involved I would expect the initial separation to have been more rapid then to slow down as the initial stress is eased.
Another puzzling point is why has so much of the mass moved north of the equator? The difference deforms the Earth and contributes to its precession.
If, as I suspect, the initial break up was violent, then the effects would probably have been nasty but limited, at the physical level, but the climate changes would have been significant once the initial openings grew wider.