Are there NO rules to evolution?

Question

http://www.reuters.com/article/healthNews/idUSN1043228620071210?feedType=RSS&feedName=healthNews&rpc=22&sp=true

Here is the "latest" rule to evolution! We humans have been "suffering" from the "breakneck" speed of the evolution of "our" species.

Months ago saw me asking the Y!A collective why oppossums haven't developed wings or longer legs in an attempt to evolved themselves out of the plight of becoming road pizza.

ALL the answers seemed to explain to me that the evolution of a particular species takes thousands of millenia to occur.

Well, apparently, these people were WRONG! Any of you have a better explanation for this story?

Answer 1

Um, yeah! They don't evolve at all... Hence, they either learn to avoid roadsides or they become road waffles.

Answer 2

No
Evolution normally does take millennia to occur in complex organisms.
That is why the more rapid evolution in humans is a problem.

Keep in mind that evolution is a response to environmental pressures and that we, humans, are subjected ourselves to lots of pollutants. We also set up conditions whereby humans with what used to be life-threatening conditions can still "live long and prosper" e.g., diabetics used to die early and not have many offsprings, now they can live longer lives and have more kids -- who will carry the gene for easier onset of diabetes -- and we also provide lots of junk food to create even more new cases of diabetes.

Evolution also takes lots of generations to occur in insects and bacteria. It's just that for these, that could be only a few years or even a few weeks (they reproduce much faster).

And there too, humans do provide incentive: people who use these bacteria killers that kill 99.99% of bacteria do not realise that the 0.01% they leave behind happen to be the ones that can survive the bacteria killer. These bacteria will reproduce so that the next generations will be better at resisting.

By the time these people get sick and get infected, they go to the hospital where we find that the antibiotics do not work on their infections. Of course, they have accelerated the artificial evolution of their bacteria towards extra-resistence to antibiotics.

Answer 3

There is only one rule in evolution. It is:

"The change that improves the odds of an organism reproducing gets passed on, the change that reduces the chance of reproducing eventually gets lost in the maze."

Not all changes take thousands of years to occur. Moths in the UK were able to change their colorization to cope with grime resulting from coal burning within a few moth generations.

The case of the opossum presents a more complex issue. In the grand scheme of things, automobiles have only been around for say 150 opossum generations. The development of wings, highly unlikely, would take many more than 150 generations. Longer legs, a possibility however remote, might occur over several thousand generations. However, neither change might enhance reproduction. By the time most opossums become road pizza, they have probably mated and achieved the reason for their existence. Perhaps the reason for opossums is to ensure that vultures have something to eat on slow days.

There is little evidence to suggest that humans are evolving at an accelerated pace. Today's humans are essentially the same as the ones who existed on the planet more than ten thousand years ago.

What has evolved, is our knowledge of the human condition. Additionally, micro organisms are evolving all the time. Evolution depends on changes over generations, human generations are about 35 years long. Virus generations might be only minutes long under certain conditions.

The changes observed in humans over the last few centuries are due to improved nutrition, sanitation and generally improved living conditions. The emergence of medical conditions that seem new, is the result of improved medicine used to care for infants. Improved medicine has allowed infants to survive that would have perished in an earlier time and their being able to reproduce has allowed recessive genetic conditions to surface.

I may sound callus, but by keeping infants alive that would have perished, we may be sewing the seeds of our own destruction.

Answer 4

Humanity can be measured in a matter of seconds on the history of this planet. There have been an estimated billions of species that have become extinct since the formation of the planet. Since humanity has sped this along in record numbers, we have forced as many species to become extinct as several ice ages there are huge gaps in the eco systems and the natural food chains on this planet. You will definitely see adaption of species within your lifetime because of this, but evolution does take a hugely significant amount of more time. If you want visible proof of evolution than look on a microbial level. Disease and bacteria are single celled, far more simple creatures, and evolve within a matter of months, sometimes days. Hence the resistant strains of disease that have never existed before your lifetime.

Answer 5

The only "rule" to evolution is that beneficial mutations (i.e., those that impart better survival) are more likely to find their way through the population than mutations that are detrimental to survival.

The Reuters article you sight points out that humans are evolving faster for specific reasons, all of which appear to make sense, such as:

1) More medical advances allowing us to live longer.
2) Rapidly expanding population that is much more mobile (i.e., 6 billion people able to travel the world and find mates elsewhere, thus giving rise to new possibilities for gene combinations in offspring).

Point 2 above is a biggy. Several hundred years ago the total human population numbered in the millions (not much genetic diversity), and it took months to travel say 1000 miles. Now there are many more people from different ethnic, economic, and geographic origins able to meet up and have offspring. That creates more genetic diversity, and thus faster evolution. But, it still takes hundreds to thousands of years.

Last time I checked, Armadillos from Asia weren't able to travel to mexico on a regular basis to mate with those from Mexico. In other words, Armadillo populations are relatively small (lower genetic diversity) and isolated from one another. Thus, Armadillo's are likely to evolve much more slowly than humans.

Answer 6

Opossums don't just decide to evolve wings or longer legs: evolution proceeds by genetic changes which are random but quite frequent, but most are DISadvantages. When occasionally a change takes place which confers an advantage (longer legs, bigger brain, binocular vision...) that change is more likely to be passed on simply because the changed organism (whether opossum, ape or bacterium), having an advantage, is more likely to survive and therefore reproduce, and the new "version" will, being better adapted to its environment, eventually drive out the old, unchanged species by breeding faster and better. Human beings are special in this regard only because they have learned not just to adapt to their environment, but to CHANGE their environment to their benefit (air conditioning, food and water sterilisation and the printing press are good examples of advantageous changes, though the first is likely short-term only.) But maybe right now that's being overdone, as we reproduce and industrialize at an accelerating rate, to our eventual detriment: we can't survive for long in a 60% CO2 atmosphere, since we need (are adapted to) breathing free oxygen and an ambient temperature of between minus10 degrees and 30 degrees (14 to 86 in Fahrenheit). Global warming, in particular the increase in the amount of CO2 and reduction in free oxygen in the atmosphere) is therefore a threat, and we are unlikely to evolve fast enough to survive it. But we HAVE evolved smart enough to avoid it, if we decide to do so; even the smartest gorilla hasn't learned to do that.

Answer 7

They weren't wrong, you are just asking for evolution on a very large scale. Even our vary fast evolution that the article talks about has only produced things like blue eyes, and other small changes within the gene pool. Even though it was quicker then originally thought, it still takes thousands of years to happen. For a species to evolve wings would still take millions and millions of years based on the sped this article talks about.

Answer 8

I was one of those people who argued with you.

You were arguing that if evolution "worked" then opossums should have evolved into a "higher life form" within the course of about 100 years (!) since the beginning of the mass-production of automobiles. (!) (At that time you didn't mention "wings" or "longer legs" ... but this just further clarifies the absurdity of your point ... that evolution should produce these kinds of changes in a mammal in the course of 100 years.)

The point I and many other people made was that you have no concept whatsoever for the kind of TIME involved.

You still don't.

Of course evolution can be rapid. Nobody denies that. But the word "rapid" is relative to *geological* time.

Read the article again. It describes measurable genetic differences in humans in the last 5,000 years due to changes in diet, and the diseases we have encountered in the last 5,000 years (which is accelerated in a large population). That is incredibly "rapid" by geological standards, but still not nearly the absurd rate you were saying should be occurring if evolution "worked."

Your misinterpretation of this article shows that you STILL use the creationist "straw-man" tactic ... misunderstanding (or misrepresenting) evolution in an absurd way ... so you can then conclude that evolution is absurd.

Answer 9

Here is the rule:
An allele set that produces a phenotype that gets its bearer killed before it reaches reproductive age will have a smaller representation in the next generation.