Tag Archives: multiverse

The monkey’s voyage

The Oligocene sees a major diversification of anthropoid primates (monkeys, apes, and humans). Among the anthropoids, the major evolutionary split is a geographic one, between platyrrhines (New World monkeys) and catarrhines (Old World monkeys, apes, and humans). Aegyptopithecus is one of the earliest primates that clearly falls on the catarrhine side of that split (although the split must go back earlier).

At Logarithmic History we traffic in Big Questions, and one of the biggest questions of all is the balance of natural law and accident in making our world. Thus physicists have long hoped to find that the laws governing our universe reduce to just a few fundamental equations, but we saw at the beginning of this blog that they are now confronting the possibility that our universe is just one among many, and that the laws of physics in our universe may incorporate a large dose of historical accident. With the discovery of extra-solar planets, we’re just beginning to get an idea of how typical or atypical our solar system is. And we’ll have a lot of opportunities to ask whether there are Laws of History (an old idea now undergoing a revival in the new field of cliodynamics*) when we move into the historical period later in the year.

The field of biogeography – the study of the geographic distribution of species – has seen some major pendulum swings in this regard. Darwin was intensely interested in questions of biogeography mainly because they could provide support for the theory of evolution. His approach could fairly be called eclectic. From sometime in the second half of the twentieth century however, a lot of biologists thought they could do better than just answering particularistic questions about how species A got to island Z. They wanted to find scientific laws.

Edward O. Wilson was an early pioneer in this area. Along with Robert MacArthur, he developed a theory of island biogeography according to which the number of species on an island is set by a predictable equilibrium between extinction (smaller islands have higher extinction rates) and colonization (remote islands have lower colonization rates). Being a good scientist he actually put this theory to the test by getting an exterminator to “defaunate” (it means what you think it means) some little mangrove islets, and showing that they returned to very close to their predicted equilibrium numbers of animal species after a while.

For the biogeography of continents (and larger islands once part of continents) the quest for scientific laws took a different turn. The discovery of continental drift and plate tectonics encouraged a school of “vicariance biogeography.” Vicariance biogeographers liked to trace current biogeographic distributions to the wanderings of continents. They were highly allergic to explanations involving accidental long-distance dispersal over big stretches of ocean.

Alan de Queiroz, in The Monkey’s Voyage: How Improbable Journeys Shaped the History of Life, provides a highly readable overview of the decline (if not quite the extinction) of the vicariance school in the face of mounting evidence for flukish dispersals as a major factor in biogeography. The dispersal of monkeys to the New World is a dramatic case in point. (Guinea pigs and their relatives are another.) About the only scenario that makes sense involves a raft of trees washing out to sea (most likely from the Congo basin) and eventually delivering a few parched, scared monkeys to the island continent of South America, where they eventually spawned the whole range of species – spider monkeys, squirrel monkeys, howler monkeys, tamarins, marmosets, capuchins – we know today. Sheer accident: change the weather a little, leave the monkeys stranded at sea a little longer, and the whole history of primates in the New World is erased.

* so new my spellchecker doesn’t recognize it.

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The monkey’s voyage

The Oligocene sees a major diversification of anthropoid primates (monkeys, apes, and humans). Among the anthropoids, the major evolutionary split is a geographic one, between platyrrhines (New World monkeys) and catarrhines (Old World monkeys, apes, and humans). Aegyptopithecus is one of the earliest primates that clearly falls on the catarrhine side of that split (although the split must go back earlier).

At Logarithmic History we traffic in Big Questions, and one of the biggest questions of all is the balance of natural law and accident in making our world. Thus physicists have long hoped to find that the laws governing our universe reduce to just a few fundamental equations, but we saw at the beginning of this blog that they are now confronting the possibility that our universe is just one among many, and that the laws of physics in our universe may incorporate a large dose of historical accident. With the discovery of extra-solar planets, we’re just beginning to get an idea of how typical or atypical our solar system is. And we’ll have a lot of opportunities to ask whether there are Laws of History (an old idea now undergoing a revival in the new field of cliodynamics*) when we move into the historical period later in the year.

The field of biogeography – the study of the geographic distribution of species – has seen some major pendulum swings in this regard. Darwin was intensely interested in questions of biogeography mainly because they could provide support for the theory of evolution. His approach could fairly be called eclectic. From sometime in the second half of the twentieth century however, a lot of biologists thought they could do better than just answering particularistic questions about how species A got to island Z. They wanted to find scientific laws.

Edward O. Wilson was an early pioneer in this area. Along with Robert MacArthur, he developed a theory of island biogeography according to which the number of species on an island is set by a predictable equilibrium between extinction (smaller islands have higher extinction rates) and colonization (remote islands have lower colonization rates). Being a good scientist he actually put this theory to the test by getting an exterminator to “defaunate” (it means what you think it means) some little mangrove islets, and showing that they returned to very close to their predicted equilibrium numbers of animal species after a while.

For the biogeography of continents (and larger islands once part of continents) the quest for scientific laws took a different turn. The discovery of continental drift and plate tectonics encouraged a school of “vicariance biogeography.” Vicariance biogeographers liked to trace current biogeographic distributions to the wanderings of continents. They were highly allergic to explanations involving accidental long-distance dispersal over big stretches of ocean.

Alan de Queiroz, in The Monkey’s Voyage: How Improbable Journeys Shaped the History of Life, provides a highly readable overview of the decline (if not quite the extinction) of the vicariance school in the face of mounting evidence for flukish dispersals as a major factor in biogeography. The dispersal of monkeys to the New World is a dramatic case in point. (Guinea pigs and their relatives are another.) About the only scenario that makes sense involves a raft of trees washing out to sea (most likely from the Congo basin) and eventually delivering a few parched, scared monkeys to the island continent of South America, where they eventually spawned the whole range of species – spider monkeys, squirrel monkeys, howler monkeys, tamarins, marmosets, capuchins – we know today. Sheer accident: change the weather a little, leave the monkeys stranded at sea a little longer, and the whole history of primates in the New World is erased.

* so new my spellchecker doesn’t recognize it.

The monkey’s voyage

The Oligocene sees a major diversification of anthropoid primates (monkeys, apes, and humans). Among the anthropoids, the major evolutionary split is a geographic one, between platyrrhines (New World monkeys) and catarrhines (Old World monkeys, apes, and humans). Aegyptopithecus is one of the earliest primates that clearly falls on the catarrhine side of that split (although the split must go back earlier).

At Logarithmic History we traffic in Big Questions, and one of the biggest questions of all is the balance of natural law and accident in making our world. Thus physicists have long hoped to find that the laws governing our universe reduce to just a few fundamental equations, but we saw at the beginning of this blog that they are now confronting the possibility that our universe is just one among many, and that the laws of physics in our universe may incorporate a large dose of historical accident. With the discovery of extra-solar planets, we’re just beginning to get an idea of how typical or atypical our solar system is. And we’ll have a lot of opportunities to ask whether there are Laws of History (an old idea now undergoing a revival in the new field of cliodynamics*) when we move into the historical period later in the year.

The field of biogeography – the study of the geographic distribution of species – has seen some major pendulum swings in this regard. Darwin was intensely interested in questions of biogeography mainly because they could provide support for the theory of evolution. His approach could fairly be called eclectic. From sometime in the second half of the twentieth century however, a lot of biologists thought they could do better than just answering particularistic questions about how species A got to island Z. They wanted to find scientific laws.

Edward O. Wilson was an early pioneer in this area. Along with Robert MacArthur, he developed a theory of island biogeography according to which the number of species on an island is set by a predictable equilibrium between extinction (smaller islands have higher extinction rates) and colonization (remote islands have lower colonization rates). Being a good scientist he actually put this theory to the test by getting an exterminator to “defaunate” (it means what you think it means) some little mangrove islets, and showing that they returned to very close to their predicted equilibrium numbers of animal species after a while.

For the biogeography of continents (and larger islands once part of continents) the quest for scientific laws took a different turn. The discovery of continental drift and plate tectonics encouraged a school of “vicariance biogeography.” Vicariance biogeographers liked to trace current biogeographic distributions to the wanderings of continents. They were highly allergic to explanations involving accidental long-distance dispersal over big stretches of ocean.

Alan de Queiroz, in The Monkey’s Voyage: How Improbable Journeys Shaped the History of Life, provides a highly readable overview of the decline (if not quite the extinction) of the vicariance school in the face of mounting evidence for flukish dispersals as a major factor in biogeography. The dispersal of monkeys to the New World is a dramatic case in point. (Guinea pigs and their relatives are another.) About the only scenario that makes sense involves a raft of trees washing out to sea (most likely from the Congo basin) and eventually delivering a few parched, scared monkeys to the island continent of South America, where they eventually spawned the whole range of species – spider monkeys, squirrel monkeys, howler monkeys, tamarins, marmosets, capuchins – we know today. Sheer accident: change the weather a little, leave the monkeys stranded at sea a little longer, and the whole history of primates in the New World is erased.

* so new my spellchecker doesn’t recognize it.

Our Good-Enough Universe

Covering the whole history of the universe naturally raises some Big Questions. We’ll consider some of these over the coming year, along with generous portions of memorable milestones, anecdotes, and curious facts.

Before we get to January 1, here’s a Big Question: why is the universe we live in well-suited for intelligent life? The answer may be related to the answer to another question: why are living things so well-adapted? Why do their various parts work together so well? The Ancient Greeks pondered this question. Some of them (Aristotle, for example) thought it was just the nature of living things to be well-adapted. But some of them offered a materialist explanation: animals with all sorts of combinations of different parts had once existed, but only some of them survived for us to see them. Lucretius, who was sort of the Roman version of Carl Sagan and Richard Dawkins (if Sagan and Dawkins had written in dactylic hexameter) wrote:

“ten thousand tribes of mortals poured forth,

fitted together in all kinds of forms, a wonder to behold. ….

as many heads without necks sprouted forth,

and arms wandered naked, bereft of shoulders,

and eyes roamed alone, impoverished of foreheads.”

But only a small fraction of these monsters – the accidentally well-adapted ones –survived. This sounds like Darwin’s theory of “survival of the fittest,” but in Darwin’s theory, the process is cumulative, and organisms get better and better adapted over time. (You can find biologist John Rees reviewing this history, and sticking up for the pre-Darwinian theory – call it “survival of the viable” – here. Also, literary critic Stephen Greenblatt reviews just how explosive the rediscovery of Lucretius was for the European Renaissance.)

Nowadays, a significant number of physicists defend a similar theory. The same process f inflation that generated our universe automatically generated vast numbers of other universes; only a small fraction of these, including ours, are fit to live in. Here’s one physicist, Leonard Susskind, doing the Lucretius thing:

“Every possible environment has its own Laws of physics, its own elementary particles, and its own constants of nature. Some environments are similar to our own but slightly different, For example, they may have electrons, quarks, and all the usual particles, but with gravity a billion times stronger than ours. Others have gravity like ours, but contain electrons that are heavier than atomic nuclei. Still others may resemble our world except for a violent force … that rips apart glaxies, molecules, and even atoms. Not even the three dimensions of space are sacred … [there may be] worlds of four, five, six, or even more dimenions.” [p.20]

Before the Big Bang?

Logarithmic History proper begins January 1, with cosmic inflation and the Big Bang; regular posting will start then. But was there anything before the Big Bang? According to some cosmologists, our universe is just one in a vast ensemble of universes, a multiverse, with new universes separate from ours constantly springing into existence. Reasons to believe this include (1)  a multiverse seems to fall naturally out of strongly supported theories of cosmic inflation, (2) the theory allows for occasional universes, including our own, to be fine-tuned for supporting intelligent life, but doesn’t require that the multiverse as a whole be fine-tuned, and (3) maybe, just maybe, there could turn out to be evidence of our universe bumping into another in its infancy.

The multiverse is hardly a well-established scientific finding. But suppose it holds up. Then — just as our star is called the Sun, just as our galaxy is called the Milky Way — our universe will need a name, to distinguish it from all the other universes. I suggest Om (rhymes with “home”).