Evolution - slower or actually faster?

[GOD]

Ok, I actually think human evolution is getting faster and not slower.. my answers in blue original article in black, link to article at the base of this post...


Human evolution is over, says UCL academic
7 October 2008

Human evolution has virtually come to a halt, according to Professor Steve Jones of UCL (University College London). Speaking today at a UCL Lunch Hour Lecture in London, Professor Jones argues that human evolution has reached the end of the line and we have arrived at utopia – or as close to it as we are likely to get.

Quite possibly if you are talking about environmental fit, but we have invented technology and that requires even more adaptive use of the mind (in particular) as a leveraging tool to fit a bigger environment, that being one of the cosmos.

“We now know so much about the process of evolution that we can make some predictions about what might happen in future,” says Professor Jones of the UCL Department of Genetics, Evolution and Environment. “To many people the future looks dystopian, doomed – an idea that goes back centuries. In modern terms, there is a fear of decay.”

In the UCL Lunch Hour Lecture today, Professor Jones outlines the three components that make up evolution: natural selection, mutation and random change.

“In ancient times half our children would have died by the age of twenty. Now, in the Western world, 98 per cent of them are surviving to the age of 21. Our life expectancy is now so good that eliminating all accidents and infectious diseases would only raise it by a further two years. Natural selection no longer has death as a handy tool.

If people don't die it doesn't decrease evolutionary change, it may well make our species more dependent on technology. In fact people who live because of technology may be the exact people who have a higher propensity for genetic mutation.

“Mutation, too, is slowing down. Yes, there are chemicals and radioactive pollution – but one of the most important mutagens is old men. For a 29-year old father (the mean age of reproduction in the West) there are around 300 divisions between the sperm that made him and the one he passes on – each one with an opportunity to make mistakes. For a 50-year old father, the figure is well over a thousand. A drop in the number of older fathers will thus have a major effect on the rate of mutation. Perhaps surprisingly, the age of reproduction has gone down – the mean age of male reproduction means that most conceive no children after the age of 35. Fewer older fathers means that if anything, mutation is going down.

If anything the age factor is going up, perhaps the average being applied is the world average? In western countries I almost absolutely bet the average age of parenthood has gone up in alignment with marriage ages and everything else.

10,000 years ago life expectancy was far less; something like 40 was a ripe old age. Furthermore, there are far more people now and more of them are having children at an older age, if you are thinking about probability of mutation "enablement" then its far more likely that that 1 in 1,000,000 child is going to be borne and pass its genes on.


“Randomness is the third, often forgotten, important ingredient in evolution. Humans are 10,000 times more common than we should be, according to the rules of the animal kingdom, and we have agriculture to thank for that. Without farming, the world population would probably have reached half a million by now – about the size of the population of Glasgow. Small populations which are isolated can change – evolve – at random as genes are accidentally lost.

They can also be contained a small geographic area, travel etc allows positive genes to be spread to farther regions.

Clustering of attributes such as in cities can mean that very intelligent "random" genes can be paired with equally unique genes, and thus the potential to be even more dispersed along the bell curve rather than an averaging.


Worldwide, all populations are becoming connected and the opportunity for random change is dwindling. History is made in bed, but nowadays the beds are getting closer together. Almost everywhere, inbreeding is becoming less common. In Britain, one marriage in fifty or so is between members of a different ethnic group, and the country is one of the most sexually open in the world. We are mixing into a global mass, and the future is brown.

I think the clustering of people of a similar ilk in cities etc is going to achieve greater evolutionary steps than with incest with related neighbours.

“So, if you are worried about what utopia is going to be like, don’t; at least in the developed world, and at least for the time being, you are living in it now.”

Nothing special about working and sleeping most of our limited lives.
I think in 1000 years we will have a better utopia than we are experiencing now. Assuming we get off this planet.

Human evolution is over, says UCL academic

[GOD]

As above, black theirs, blue mine...

The British geneticist Steve Jones has recently given a lecture at University College London entitled “Is human evolution over?” His answer to his own question is in the affirmative. I agree with Jones that human evolution has pretty much stopped, but for entirely different reasons.
His argument is that human evolution, at least in the western societies, has stopped or slowed down because very few older men in such societies reproduce. Sperm of older men carry many more mutations than those of younger men. Mutations provide the source of genetic variations on which natural selection works. Hence, no older fathers, no genetic mutations, no evolution.
Jones may be right; however, I think he is underestimating how long ago human evolution stopped. I think it stopped roughly 10,000 years ago, with the advent of agriculture.

Guess nobody considered that women have children at older ages now.. Yes, supposedly the genetic bundle stays constant with fewer mutations, but I would guess that the mother's womb and other aging factors could have different developmental effects.

Men are definitely older now when they have children,

In recent years, the number of men in their 40s who become fathers has continually grown. In 2006, about 24 thousand babies were born whose fathers were in their 40s, i.e. 14 percent of all babies born in 2006, as against 9 percent a decade ago.

CBS - More men in their 40s become fathers - Web magazine

These findings suggest that older fathers produce higher frequencies of XY sperm,

Frequency of XY sperm increases with age in fathers of boys with Klinefelter syndrome

More boys with a higher genetic mutation rate.

Getting back to the agriculture aspect, I thought good nutrition enabled intellectual development? This is an evolutionary advance which has been improving all the time, better nutrition means quite possibly more intelligent children as they can achieve closer to their genetic potential.


Evolution takes many generations, and so the speed of evolution of a species is relative to how long it takes for individuals of the species to mature sexually and start reproducing (holding constant, for the moment, the other important determinant of the speed of evolution, the strength of selection pressure). Evolution happens faster for fast-maturing species and slower for slow-maturing species. Fruit flies are one of the fastest-maturing species in nature, and humans are one of the slowest. It takes only seven days for fruit flies to mature sexually under ideal conditions, whereas it takes 15 to 20 years for humans. It means that there can be more than 50 generations of fruit flies in one year, before a human baby can even begin to walk. There are more than a thousand generations of fruit flies in one human generation (20 years), for which human need more than 20,000 years. Evolution for fruit flies can happen pretty fast, which is precisely the reason why they are the favorite species for geneticists to study. Human evolution happens much, much more slowly. No human scientists can see it in action the way they can observe fruit fly evolution unfold in the lab.

Slight flaw in this argument. I don't see fruit flies at the top of the food chain or searching space. There are plenty of animals that replicate faster than humans and have evolved less; simple replication isn't the absolute in correlation with evolution. The propensity for genetic mutation may well be, in fact it’s more likely a function of speed and variability.

Natural selection under most circumstances requires a stable, unchanging environment for many, many generations (once again, unless the selection pressure is enormously strong). For example, if the climate is very cold for centuries and millennia, then gradually individuals who have better resistance to cold will be favored by natural selection, and their neighbors who have less resistance to cold (who are more adapted to a hot climate) will die out before they can leave many children. This will happen generation after generation, until one day all humans have great resistance to cold. A new trait – resistance to cold – has now evolved and become part of universal human nature. But this trait could not have evolved if the climate was cold for one century (only five human generations, albeit 5,200 fruit fly generations) and then hot for another century, only to be cold again in the third century. Natural selection would not know who (with which traits) to select.

Its the degree of variability that is most likely to matter, There is no evidence to suggest that the climate is less variable now than it was 10000 years or more ago, quite possibly could argue that we feel the effects of the changes in climate now. But that would allow greater variety to exist and create a greater dispersion of mutations to survive.

Continued.... below

[GOD]

Since the advent of agriculture about 10,000 years ago and the birth of human civilization which soon followed, humans have not had a stable environment against which natural selection can operate. For example, a mere two centuries (10 generations) ago, the United States and the rest of the Western world were largely agrarian; most people were farmers. In the agrarian society, men achieved higher status by being the best farmers; those who possessed certain traits that made them good farmers had higher status and thus greater reproductive success than others who didn’t possess such traits.
Then, only a century later, the United States and Europe were predominantly industrial societies; most men made their living working for factories. Traits that make men good factory workers (or, better yet, factory owners) may or may not be the same as the traits that make them good farmers. Certain traits – such as intelligence, diligence, and sociability – probably remained important, but others – such as a feel for nature, the soil, and animals, and the ability to work outdoors or forecast weather – ceased to be important, and other traits – such as punctuality, the ability to follow instructions, a feel for machinery or mechanical aptitudes, and the ability to work indoors – suddenly became important.
Now, only one century later, we are in a post-industrial society, where most people work neither as farmers nor factory workers but in the service industry. Computers and other electronic devices become important, and an entirely new set of traits is necessary to be successful. Bill Gates and Sir Richard Branson (and other successful men of today) may not have made particularly successful farmers or factory workers. All of these dramatic changes happened within 10 generations, and there is no telling what the next century will bring and what traits will be necessary to be successful in the 21st century. We live in an unstable, ever-changing environment, and have done so for about 10,000 years.

As mentioned before, clustering of types through the division of labour will achieve those homogenous environments that allow more pronounced positive adaptations to occur, especially where they are unique.


For hundreds of thousands of years before that, our ancestors lived as hunter-gatherers on the African savanna and elsewhere, in a stable, unchanging environment to which natural selection could respond. That is why all humans today have traits that would have made them good hunter-gatherers in Africa – men’s greater spatiovisual skills, which allowed them to follow animals on a hunting trip for days and for miles without a map or a global positioning device and return home safely; and women’s greater object location memory, which allowed them to remember where fruit trees and bushes were and return there every season to harvest, once again without maps or permanent landmarks.
For the last 10,000 years or so, however, our environment has been changing too rapidly for evolution to catch up. Evolution cannot work against moving targets. That’s why humans have not evolved in any predictable direction since about 10,000 years ago.

Completely wrong, evolution doesn't "catch up" evolution is what exists. Greater variations in habitat just mean that different humans fit different ecological niches. Evolution isn't about uniformity it’s about pace of change, and the pace of change for humans is speeding up all the time.

It’s well known that viruses can affect the human DNA. The average person on the London underground comes into more contact with more viruses and strains in a single trip (On a packed train) than people could expect to come into contact with in their lifetime some 10000 years ago...

I hasten to add that certain features of our environment have remained the same – we have always had to get along with other humans, and we have always had to find and keep our mates – so certain traits, like sociability or physical attractiveness, have always been favored by natural and sexual selection. But other features of our environment have changed too rapidly relative to our generation time, in a relatively random fashion – who could have predicted computers and the internet a century ago? – so we have not been able to adapt and evolve against the constantly moving target of the environment.

We are adapting to the changing environment that’s evolution. Just as talking was collaboration, now we have far more tools of collaboration which we leverage to achieve even far greater feats. If outcomes are a measure of evolution then we are changing rapidly.

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