The more you think about life on land, the less sense it makes. Life started in the ocean about 4 billion years ago, and for 3.5 billion years, it remained there. Evolution created organisms that had to stay wet- -they were essentially fluid-filled bags, and if they dried out, their circulatory systems would collapse, and most of their proteins and DNA would crumple up into uselessness. Without the ocean’s nutrient-filled currents, they would starve, and they and their fragile eggs and larvae would be immobile, unable to reach new or better habitats.
Seen from the sea, then, the land should equal death. Yet since animals, plants, and fungi first came ashore some 450 million years ago, life on land has been outrageously successful. True, land organisms have had to remain fluid-filled, DNA-based sacs, and they still rely on the old- fashioned, oceanic ways of getting food and energy, such as predation and photosynthesis. But according to the best estimates, there are now twice as many species on land as there are in the seas, and they produce some 50 times as much biomass. Furthermore, they manage this on only one-third the ocean’s breadth and in only a tiny fraction of its depth. And they achieved these luxuriant statistics in very little time. If ocean life were a 100- year-old man, life on land would be an 11-year-old child.
Researchers have tried to explain this land-sea paradox, in bits and pieces, without much success. But Mark and Dianna McMenamin, a husband- and-wife paleontological team, have an imaginative new hypothesis that they believe can explain it all, at one go. To understand the success of life on land, they say, you have to recognize that it is a unified whole. What makes it different from marine life is that unrelated terrestrial organisms--plants, fungi, and animals--form a vast number of direct, physical connections through which fluid can move. In effect, the McMenamins claim, life on land has not so much forsaken the sea as created a new sea within the sum of its tissue--something Dianna and Mark have dubbed Hypersea.
Hypersea is in many ways different from an ocean: for
Seen from the sea, then, the land should equal death. Yet since animals, plants, and fungi first came ashore some 450 million years ago, life on land has been outrageously successful. True, land organisms have had to remain fluid-filled, DNA-based sacs, and they still rely on the old- fashioned, oceanic ways of getting food and energy, such as predation and photosynthesis. But according to the best estimates, there are now twice as many species on land as there are in the seas, and they produce some 50 times as much biomass. Furthermore, they manage this on only one-third the ocean’s breadth and in only a tiny fraction of its depth. And they achieved these luxuriant statistics in very little time. If ocean life were a 100- year-old man, life on land would be an 11-year-old child.
Researchers have tried to explain this land-sea paradox, in bits and pieces, without much success. But Mark and Dianna McMenamin, a husband- and-wife paleontological team, have an imaginative new hypothesis that they believe can explain it all, at one go. To understand the success of life on land, they say, you have to recognize that it is a unified whole. What makes it different from marine life is that unrelated terrestrial organisms--plants, fungi, and animals--form a vast number of direct, physical connections through which fluid can move. In effect, the McMenamins claim, life on land has not so much forsaken the sea as created a new sea within the sum of its tissue--something Dianna and Mark have dubbed Hypersea.
Hypersea is in many ways different from an ocean: for