Joined: Sep. 2002
|Quote (dvunkannon @ April 18 2009,18:00)|
|Quote (olegt @ April 18 2009,17:23)|
Nakashima is awesum.
Nakashima raises his sake cup in response, sir. You are too kind.
And if anyone would like to respond seriously to N-san's thoughts on macro-evolution on the Texas Chainsaw School Board thread, he would be honored.
I am also very interested in discussing macro-evolution. However, I think it would be more useful to avoid confrontation and hyperbole to advance that discussion.
Here are some of my initial thoughts on the subject. I freely admit that I have not thought about this subject as long as some others, and certainly don’t know the literature completely.
The operators of micro-evolution, i.e. variation, selection, time, and scarcity, are insufficient to explain the diversity of life. To explain this diversity we must appeal to other historical and ecological concepts, and see how they push or pull the micro-evolutionary engine in certain directions.
Part of the historical context includes
- the distance of the earth from the sun
- changing solar radiation
- plate tectonics
- axial tilt
- existence of the moon (tides)
I believe the last three are very important to understanding macro-evolution. What this adds to micro-evolution is a distribution in space as well as time, and a dynamism to that distribution which helps keep life from falling into a stable equilibrium.
The other major context is ecology, the recognition that other life forms a significant part of the environment.
- competitors for resources
- source of energy and organic chemicals
- source of information
- source of niche (Co-evolution)
Even more than the dynamic physical environment, the dynamic ecological environment drove macro-evolution.
In outline, these are the things that I think have operated historically, and operate today, to drive macro-evolution. To these could be added very basic issues of physics such as the cube square law and the properties of materials that form fundamental constraints on variation.
Micro-evolution itself does not predict the tension between reproductive success from isolation (not having to share resources) and reporductive success from closeness (neighbors are resources). In our world, the balance is tipped towards success from closeness, which has led to biofilms, bacterial signalliing, the evolution of predation, arms races, and cooperation, the preference for self similarty, sex, and multi-cellularity, symbiosis and parasitism.
So that is my thesis, that the engine of micro-evolution, combined with physical and ecological dynamism over long periods of time, is sufficient to explain the level of biodiversity that exists today and the pattern of biodiversity shown in the fossil record.
I would be happy to discuss it further with you.
Is Mr Nakashima on moderation? Dave Wisker (me) is all of the time. Frakking annoying.
Those who know the truth are not equal to those who love it-- Confucius