There is no general reason to expect evolution to be progressive - even in the weak, value-neutral sense. There will be times when increased size of some organ is favoured and other times when decreased size is favoured. Most of the time, average-sized individuals will be favoured in the population and both extremes will be penalised. During these times the population exhibits evolutionary stasis (i.e., no change) with respect to the factor being measured. If we had a complete fossil record and looked for trends in some particular dimension, such as leg length, we would expect to see periods of no change alternating with fitful continuations or reversals in direction - like a weathervane in changeable, gusty weather.

... leaders who forbid their followers to use effective contraceptive methods ... express a preference for 'natural' methods of population limitation, and a na…

Another force driving progressive evolution is the so-called 'arms-race.' Prey animals evolve faster running speeds because predators do. Consequently predator…

But you cannot have an unnatural welfare state, unless you also have unnatural birth control, otherwise the end result will be misery even greater than that wh…

If an organised body is not in the situation and circumstances best adapted to its sustenance and propagation, then, in conceiving an indefinite variety among …

The powerful retractile talons of the falcon- and the cat-tribes have not been produced or increased by the volition of those animals; but among the different …

One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.