Has Natural Selection Met Its Match?

[-Sigurd-]

"...human beings really are, because of culture, an importantly different sort of thing."

Daniel Dennet, 'The Computational Perspective'

What is unique about our species is our ability to reason, understand and communicate that understanding to others and to record it for the benefit of others yet to come. As a result our knowledge and understanding accumulates over time regardless of what is happening to our genes.

And using that accumulated knowledge we can respond to changes in our environment by manipulating our immediate environment in 'real time'. We don't have to wait for nature to adapt us to environmental changes by doing a cull of everyone with a mal-adapted genotype. Also, human civilisation , increasingly, makes provision for the weak, the sick and the disadvantaged. In human civilisation, it is no longer necessary to be physically strong or even particularly intelligent - these things may still help advance one, but they are no longer necessarily life or death issues as they are in the rest of the animal kingdom.

So, is man's evolution(at least through natural selection) over? Will we be in the driving seat of our own evolution from now on?

[ScabbyDouglas]

I think that some of what you say is absolutely correct, Sigurd. Human society, and more specifically, civilisation, does insulate us from evolutionary pressure to a great extent. The weak, infirm, old and enfeebled, have much greater survival rates in human societies than can be envisaged in any other species.

And yes, we can to an extent, manipulate the environment around us in limited ways to reduce the necessity for physical adaptation to environmental changes. Of course, we have to recognise that the cost to us in resource expenditure is likely to become higher all the time - take a very limited example: Global warming.

The long term effects of Global Warming are unclear, however, suppose that in general, global mean temepratures rise. Although we imagine that we will just have to use more air-conditioning, and adapt our agriculture to suit, each of those tactics bears an associated cost: increased energy expenditure on one hand, and possibility of starvation or at least hardship in many areas while agriculture adapts to the new climate model.

What is evident however, about civilisation as a whole, is that while it is excellent at improving the survival chances of individual human beings, it has been remarkably bad for the health of the rest of the planet. As a species, I'd suggest that we are individually, and in small groups, very very smart. However, as a species, living in civilisations, we are fairly dumb.

In evolutionary terms, it's way too early to determine the success of homo sapiens. If we can successfully survive the kind of mass Extinction Events (asteroid strike, major volcanic activity etc..) that seem to have punctuated the geological record, then we'll have something to be pleased about. Currently, however, we have managed to push up the global thermostat (all by ourselves), and for many species have constituted a small-scale extinction event all on our own.

What makes humanity, rather than humans, successful is our culture/society/civilisation. We don't need to adapt any more, we may not need to evolve much (unless conditions change to such an extent that our technology and society cannot deal with the rate of change and break down), but our collective intelligence needs to improve - we need to get smarter as a species, the next evolutionary steps need to be social ones, cultural and technological.

Humanity as a species has more in common with insects that live in hive structures than might at first be apparent. The important thing for humanity is not whether individually we are fitted to survive in a savage natural environment, but whether our culture is fitted to survive.

[HollyElise]

hmmm. Actually one way to measure the success or failure of a species is how quickly it changes into something else. I once heard it said, "humans are an evolutionary mistake waiting to be corrected."

Sharks are SO much older than us but have changed very little. Spiders have changed even less. Humans however are changing rapidly... we are losing our little toe, we're getting much larger, our organs are changing, we're living far longer and women are having longer reproductive years... from an evolutionary point of view, we are changing because we were not suited to our environment as we were. Sharks and spiders on the other hand are of such good design that they are far better at surviving and adaptation, even through some dramatic climatic changes.

[ScabbyDouglas]

HollyElise, I agree that humans are still changing, and to some extent that can be seen as evolving.

However, when we think about evolution, we are usually referring, I guess, to changes which are driven by environmental pressures - that is - those individuals not bearing the modifications are less likely to survive, or reproduce. In the case of humankind, that is patently no longer the situation. Think of those couples who have been unable to have children without medical intervention - in vitro fertilisation or surrogacy- just for one example. In earlier days these couples would not pass on their genetic make-up, now they do. This is not a criticism - just an observation.

As a species, we are so insulated from the real environment - the world at large - and so cocooned within our artifical micro-environments - our cars, homes, offices, shopping malls - that the attrition waged by "natural causes" upon the less-well-fitted for survival (amongst whom, incidentally, I count myself), is no longer a factor.

[ScabbyDouglas]

Sooo..... yeaaahhhhh...


Anyway, where were we?

As far as the original question which was about Natural Selection Having Met Its Match, I think it can be justifiably argued that humankind is under no immediate threat to its survival from the environment. However, should we be faced with some Mass Extinction Level event such as meteorite strike, or cataclysmic volcanic eruption, then we'll see just how effective our technology and society is...

[ScabbyDouglas]

Ahh Tom ,Tom ... here you are back again.
I have to wonder - will the citing other people's work in lieu of engaging your own brain never cease?

Heheh... natural selection has been challenged by "parapsychology"? I also hear that Brownian Motion has been challenged by voodoo.

[ANDY-J2]

Originally posted by TomSawyer

I have observed a grouping of birds, all sitting on the field, and at the same time leaving up in the air and in the same direction. How is this possible under the model of Darwin? How could each bird know exactly when to get up, and in that particular direction? Any sensible person can see that it was a group mind or one 'leader' bird communicated the 'plan' to the rest, in a fraction of a second.

If someone pointed a gun at you then you would flinch-it would be a reflex action and that is exactly what is occuring when a flock of birds flies into the air simultaneously.One bird,not necessarily a "leader" perceives a threat of danger and reacts instinctively and this triggers a response in the other members of the flock.It is called the herd instinct and animals group together precisely because it increases the chances of detecting danger.It has nothing to do with any plan or group minds-it has to do with instincts and conditioned responses to the threat of danger.