New theory on the origin of primates

New theory on the origin of primates

This theory proposes plate tectonics as a major factor in the divergence of primate species.

"Divergence between strepsirrhines (lemurs and lorises) and haplorhines (tarsiers and anthropoids) is correlated with intense volcanic activity on the Lebombo Monocline in Africa about 180 million years ago. The lemurs of Madagascar diverged from their African relatives with the opening of the Mozambique Channel (160 million years ago), while New and Old World monkeys diverged with the opening of the Atlantic about 120 million years ago."

This study would seem to support the theory of punctuated equilibrium. Adaptation acquisition (genetic or behavioral) requires a forcing mechanism. That is, adaptation doesn't occur in the absence of some stressing factor (competition, climate change, geographic separation, etc.) It seems likely to me that competition and predation, for instance, provides for a constant stressor as a mechanism for a more gradual evolutio (think elk and wolves or trees competing for sunlight in a rain forest). In addition, there are catastrophic evolutionary events (continents colliding or separating) that give rise to an evolutionary history that is more punctuated in nature.

It's tempting to think that evolution is analogous to technological advancement, the improvement of a design through constant trial and error, becoming more sophisticated through time. I try to teach my students otherwise, though. We tend to think of the most sophisticated animals as the most "highly evolved." Primates, marine mammals, and orchids are highly sophisticated. I teach that biological sophistication is not the goal of evolution. The goal of evolution is the persistence of genes through time, and success is measured by the ability of genes to perpetuate.

One of my favorite examples of the is the tapeworm. Its hard to argue that tapeworms are physiologically sophisticated and yet they are very highly evolved. Especially when you consider their evolutionary history with humans.