The Human Impact on Evolution

[Laurens]

Never before in the history of life have species been able to cross the globe on ships and aeroplanes, being introduced to new habitats to wreak havoc on ecosystems. There is little doubt that humans have changed the ballpark as far as evolution is concerned.

We're already decreasing biodiversity at a faster rate than we can discover just how diverse it was in the first place...

I was going to ask you guys a speculative question; assuming humans do not go extinct, what affects do you think our presence will have on the future evolution of life? Will life ever reach past levels of diversity again, or will our global enterprises put an end to that for good?

 

[KittenKoder]

Never before in the history of life have species been able to cross the globe on ships and aeroplanes, being introduced to new habitats to wreak havoc on ecosystems. There is little doubt that humans have changed the ballpark as far as evolution is concerned.

We're already decreasing biodiversity at a faster rate than we can discover just how diverse it was in the first place...

I was going to ask you guys a speculative question; assuming humans do not go extinct, what affects do you think our presence will have on the future evolution of life? Will life ever reach past levels of diversity again, or will our global enterprises put an end to that for good?

This is a question I often use to point out a flaw with environmental change proponents, ironically. We have seen organisms often adapting to our toxins, not all dangerous ones (though some are dangerous), yet we kill off even the ones that could help a lot .. not sure why, I mean, I am really baffled by why we genocide an organism with possible benefits that's strong enough to survive in our toxins. So yes, I think we will ultimately be a catalyst to a golden age of evolution much like the one that sparked the mammals. If we would just let nature be nature.

 

[Anachronous Rex]

A few things come to mind:

1) Aggressive animals, or animals that can prey on us tend to not do very well, expect to see fewer of these in the wild.

2) We should expect nearly identical ecosystems in terms of flora throughout most of the world, arranged along lines of temperature and and average rainfall. There will be obvious exceptions in cases of very particular ecosystems

3) I would expect something similar with fauna, but with a few surprises as some creatures seem to do very well in all sorts of environments, while others fold very easily to outside competition, and it's not always clear which is which. Rats and dogs are obvious winners, but I for instance probably would not have put money on Southeast Asian constrictors or Monitor Lizards, which tend to do quite well in new environments. In any case, specialists are out in the first few rounds of exchange. Only more generalized forms will pull through.

4) Over time, expect domesticated animals, or other animals able to deal well with humans, to begin filling in vacant or undeserved niches do to their numerical advantages. Given long enough stretches of time, we could expect Dogs, Raccoons, Cats, and Pigs to adapt to and occupy all sorts of new and exiting roles.

5) Expect new species and subspecies adapted to living in city environments. Cats, for instance, might enhance their climbing abilities and adapt their underbelly (which expands while falling, slowing their terminal velocity) into fully developed gliding flaps similar to those found in some rodents, enabling them to predate city pigeons more effectively. Just to give one example.

But I'm not really sure how to answer beyond that. It seems clear that present trends are unsustainable, so assuming we are to survive our behavior would have to change. Since I don't know what that change would look like, I don't know how to factor that change into future projections.

Also, I expect at some point we will master cloning and gene cataloging, and at that point we should more or less stop loosing species, though probably many of them will exist only in zoos.

 

[Anachronous Rex]

This is a question I often use to point out a flaw with environmental change proponents, ironically. We have seen organisms often adapting to our toxins, not all dangerous ones (though some are dangerous), yet we kill off even the ones that could help a lot .. not sure why, I mean, I am really baffled by why we genocide an organism with possible benefits that's strong enough to survive in our toxins. So yes, I think we will ultimately be a catalyst to a golden age of evolution much like the one that sparked the mammals. If we would just let nature be nature.

I'm not sure what you are talking about... I suspect antibiotics, but that seems incredibly silly so I'll give you the benefit of the doubt.

In any case, have a looksy at this:
http://news.stanford.edu/news/2011/march/permian-mass-extinction-032411.html
Organisms that can better survive severe ecological trauma then most are often a greater threat to the biosphere then the trauma itself.

 

[KittenKoder]

This is a question I often use to point out a flaw with environmental change proponents, ironically. We have seen organisms often adapting to our toxins, not all dangerous ones (though some are dangerous), yet we kill off even the ones that could help a lot .. not sure why, I mean, I am really baffled by why we genocide an organism with possible benefits that's strong enough to survive in our toxins. So yes, I think we will ultimately be a catalyst to a golden age of evolution much like the one that sparked the mammals. If we would just let nature be nature.

I'm not sure what you are talking about... I suspect antibiotics, but that seems incredibly silly so I'll give you the benefit of the doubt.

In any case, have a looksy at this:
http://news.stanford.edu/news/2011/march/permian-mass-extinction-032411.html
Organisms that can better survive severe ecological trauma then most are often a greater threat to the biosphere then the trauma itself.

However, you cannot deny that such a trauma ultimately leads to a bigger diversity. Essentially, it's like keeping an optimistic view that what we've done by over populating could at least do something good. We've pretty much tilted the balance already, and even if we correct our mistake, the damage is already done. We can't change it, so I'm thinking of a possibly positive effect we may have. Also note, it's not based on solid evidence or science, this is just my wishful thinking most likely, but something good has to come from the mess.

 

[Anachronous Rex]

However, you cannot deny that such a trauma ultimately leads to a bigger diversity.

Umm... yes. Yes I can.

Did you read the article? For 5 million years life struggled to exist, and when it did begin to recover it wasn't more diverse, it was less so. We completely lost entire lineages, and we will never see their like again.

Essentially, it's like keeping an optimistic view that what we've done by over populating could at least do something good. We've pretty much tilted the balance already, and even if we correct our mistake, the damage is already done. We can't change it, so I'm thinking of a possibly positive effect we may have. Also note, it's not based on solid evidence or science, this is just my wishful thinking most likely, but something good has to come from the mess.

Well yes, and when cephalopods rise to claim the earth they probably will say, "and we owe it all to the human mass-extinction which wiped out all the non-mole-ratian mammals and gave our primitive ancestors a chance."

But lest we forget, the worst case scenario here isn't the equivalent of some cretaceous cataclysm, it's this:

And I think that it is fairly important we not let that happen.



This is a digression however, the topic is not about runaway greenhouse effect, it is about the continued impact of humans on the planet. And this will result in a net loss of diversity if for no other reason than so much of the planet's ecology is tied up feeding us. Food production on earth is more or less a zero-sum game, more humans means less food for everything else.

 

[Unwardil]

Never before in the history of life have species been able to cross the globe on ships and aeroplanes, being introduced to new habitats to wreak havoc on ecosystems. There is little doubt that humans have changed the ballpark as far as evolution is concerned.

We're already decreasing biodiversity at a faster rate than we can discover just how diverse it was in the first place...

I was going to ask you guys a speculative question; assuming humans do not go extinct, what affects do you think our presence will have on the future evolution of life? Will life ever reach past levels of diversity again, or will our global enterprises put an end to that for good?

I would go so far as to say that the one necessitates the other. In order for humanity to survive natural selection must cease, at the very least for us, to be succeeded by human selection. The logical extreme of this is a full scale domestication of all life on the planet and essentially the end of massive bio-diversity. Maybe I'm naive in this assumption but, at least from a humanistic standpoint, I fail to see how that could be anything but a fantastic thing. Oh deary deary me what ever will we do without a billion and one different varieties of fungus, many of which cause horrible diseases if you inhale their spores? I don't see the down side, honestly.

 

[Laurens]

However, you cannot deny that such a trauma ultimately leads to a bigger diversity. Essentially, it's like keeping an optimistic view that what we've done by over populating could at least do something good. We've pretty much tilted the balance already, and even if we correct our mistake, the damage is already done. We can't change it, so I'm thinking of a possibly positive effect we may have. Also note, it's not based on solid evidence or science, this is just my wishful thinking most likely, but something good has to come from the mess.

1. We're bringing invaders which can quickly disrupt ecosystems and wipe out species - which decreases diversity. As long as we fly around the world taking rats and all sorts of other critters with us, we will have a decreasing effect on biodiversity.

2. We're destroying habitats at an alarming rate. This removes a great deal of biodiversity.

3. We have a tendency to hunt and kill animals (such as chimpanzees for bush meat) - this also decreases biodiversity.

So long as this continues biodiversity will go down rather than up. The difference between now and when the dinosaurs died out was that there is nothing preventing diversity afterwards. So long as we are around, doing those three things then biodiversity is going to decrease.

 

[Laurens]

I would go so far as to say that the one necessitates the other. In order for humanity to survive natural selection must cease, at the very least for us, to be succeeded by human selection. The logical extreme of this is a full scale domestication of all life on the planet and essentially the end of massive bio-diversity. Maybe I'm naive in this assumption but, at least from a humanistic standpoint, I fail to see how that could be anything but a fantastic thing. Oh deary deary me what ever will we do without a billion and one different varieties of fungus, many of which cause horrible diseases if you inhale their spores? I don't see the down side, honestly.

Yes we might not miss deadly fungi, but what happens if the ecological havoc we wreak gets rid of something like bees?

Ecosystems are extremely fragile, and if we do not take care over our actions we might end up destroying one of the species that we depend upon.

 

[WarK]

Never before in the history of life have species been able to cross the globe on ships and aeroplanes, being introduced to new habitats to wreak havoc on ecosystems. There is little doubt that humans have changed the ballpark as far as evolution is concerned.

Organisms that can better survive severe ecological trauma then most are often a greater threat to the biosphere then the trauma itself.

Isn't this how life works? From your statements it seems you see ecosystems as static, which they're not.

Coincidentally, BBC have just aired a documentary, presented by Ian Stewart, about how life took part in forming Earth. Here's the link to the show's site: How to Grow a Planet

I know you realise that life is constantly changing and adapting to new circumstances and I find it curious that you seem to implicitly, perhaps subconsciously, default to position that life is supposed to be static. Or is it that this time it's done by us, humans? I don't think we're that important, we may be having a big impact on life on this planet buy I don't think we'll be the last chapter.

In the documentary, while talking about domestication of wheat, Ian Stewart asks the question Who is using who?. So, perhaps our aeroplanes and ships are just means for various species to survive and expand to new places?

 

[Unwardil]

I would go so far as to say that the one necessitates the other. In order for humanity to survive natural selection must cease, at the very least for us, to be succeeded by human selection. The logical extreme of this is a full scale domestication of all life on the planet and essentially the end of massive bio-diversity. Maybe I'm naive in this assumption but, at least from a humanistic standpoint, I fail to see how that could be anything but a fantastic thing. Oh deary deary me what ever will we do without a billion and one different varieties of fungus, many of which cause horrible diseases if you inhale their spores? I don't see the down side, honestly.

Yes we might not miss deadly fungi, but what happens if the ecological havoc we wreak gets rid of something like bees?

Ecosystems are extremely fragile, and if we do not take care over our actions we might end up destroying one of the species that we depend upon.

Well your proposition automatically precludes the possibility that we eliminate a species either purposefully or accidentally that we depend on for survival.

But even so, that's what I like to think of as an engineering problem. We don't need bee directly, the plants we grow for food need them. There are many solutions to this problem, either by making more survivable bees or making self pollinating crops or introducing another species to take the roll of bees for pollination. It's not correct to say we depend on bees, rather we depend on SOMETHING to go and do the tedious job of facilitating the sexing of crops. At the moment, that happens to be bees. They could be replaced and the species homosapien would be none the poorer for it.

 

[Anachronous Rex]

Isn't this how life works? From your statements it seems you see ecosystems as static, which they're not.

Well my post was a reaction to Kitten's slightly off-topic comment about our "toxins," and I'm still not quite sure what she meant by that. I merely intended to point out that poisoning an entire biosphere would, I think, basically guarantee that only microbes would thrive... and I'm pretty sure that would be very, very bad.

Let me put it this way: seas of carbonic acid filled with microbes that suck out all the oxygen and kill any living marine organism larger than a minnow seem, to me, not a good thing. Not a success story of life finding a way, so much as one disaster precipitating another (greater) one. I'm not sure how one would put a positive spin on that.

But thanks for the link.

 

[Laurens]

Isn't this how life works? From your statements it seems you see ecosystems as static, which they're not.

That isn't what I meant, I know that ecosystems will not be destroyed for good, my point is that we have a penchant for introducing alien species to areas can turn an ecosystem on its head.

Take the zebra mussel for example, it is spreading through the Great Lakes, it kills native species of mussel by sealing their shells shut - which generally disappear after 4 years, they suck out most of the plankton which small crustaceans depend upon, starving off the fish that depend upon those as well. Sure an ecosystem re-establishes itself, but it is never the same. That is what I meant be wreaking havoc on ecosystems.

 

[WarK]

That isn't what I meant, I know that ecosystems will not be destroyed for good, my point is that we have a penchant for introducing alien species to areas can turn an ecosystem on its head.

You could look at it from different perspective. Those species use us to travel and conquer new ecosystems. You could look at humans and see how we were changed by other organisms.

I'm just noting that we're part of life on this planet. A more interesting point is that we're the first species able to directly tweak genetic make-up of other species and how this could impact evolution.

 

[Dragan Glas]

Greetings,

Never before in the history of life have species been able to cross the globe on ships and aeroplanes, being introduced to new habitats to wreak havoc on ecosystems. There is little doubt that humans have changed the ballpark as far as evolution is concerned.

We're already decreasing biodiversity at a faster rate than we can discover just how diverse it was in the first place...

I was going to ask you guys a speculative question; assuming humans do not go extinct, what affects do you think our presence will have on the future evolution of life? Will life ever reach past levels of diversity again, or will our global enterprises put an end to that for good?

I think that there are several ways in which humans are affecting evolution.

1. Relocation of species of flora and fauna

a) Unintentional

As mentioned, various organisms - both flora and fauna - being accidentally (on our part) transported to other parts of the world. Plague-carrying Black rats from Asia on sailing ships, for example - which affected our evolution as much as theirs, along with other native species of flora and fauna.

And, as time and transportation has increased, such relocations and colonizations of flora and fauna has increased.

b) Intentional

One example would be the intentional introduction of the Cane toad to Australia, which failed in its intended purpose, and resulted in various indigenous snake species evolving smaller heads over a very short period of time - half-a-century, if I remember correctly. This also means that the other species of frogs, toads and lizards, upon which their larger-headed ancestors would have predated, have gained an advantage - once they've outgrown the new smaller head size, their population will increase - unless other species (Dingoes?, birds of prey?) keep their population down, which will - in turn - change their population curves.

Not to mention resulting in the poisoning of young children, as well as increasing chemical addiction, where adult human addicts lick the toad to become "high".

2. Alteration of species of flora and fauna

a) Destruction of environment

Whether by accident or design, deforestation and culls affect both flora and fauna and the evolution of all related species in a ecology.

Not to mention those involving "keystone" and "apex" species.

b) Pollution

Anthropogenic climate change is clearly affecting evolution.

c) Husbandry

Clearly, throughout human history, husbandry has played a huge part in changing evolution - both of bred species of flora and fauna, and ourselves.

b) Genetic engineering

More recently, modern advances in molecular biology have enabled genetic engineering of crops, leading to real and/or imagined concerns of cross-contamination of non-engineered crops and native flora. Engineering of fauna - pigs, etc, to produce pharmaceutical products - may become even more controversial, given the concerns over increasing the virulence of animal-human cross-species transference of infections diseases.

And then there's cloning...

================================

I seem to recall that many of these issues were dealt with in a book - Dark Nature by Lyall Watson?!

I seem to recall his mentioning eight principles behind nature going bad, but I can't recall whether it was his book or another's. One of those was species being out of their natural environment - that's where the Cane toad example came from.

Clearly, humans are having quite an impact on evolution - including our own future evolution and survival.

The book, The World Without Us, deals with what happens if we go extinct.

Kindest regards,

James

 

[Laurens]

You could look at it from different perspective. Those species use us to travel and conquer new ecosystems.

My main point is that this has never happened before in the history of life, and this has undoubtedly changed the game of evolution to some extent.

I never really made any explicit judgement as to whether this is good or bad, although I guess my use of terms such as 'wreaking havoc' might have given a hint of negativity.

In my personal opinion decreasing biodiversity is a bad thing, because I find the diversity of life fascinating and for that reason I think it is something that should be preserved, however I was trying my best to keep my subjective opinions out of this topic, and attempting to stick to the question of how human activity is affecting diversity, rather than whether it is good or not.

 

[Dragan Glas]

Greetings,

You could look at it from different perspective. Those species use us to travel and conquer new ecosystems.

My main point is that this has never happened before in the history of life, and this has undoubtedly changed the game of evolution to some extent.

I never really made any explicit judgement as to whether this is good or bad, although I guess my use of terms such as 'wreaking havoc' might have given a hint of negativity.

In my personal opinion decreasing biodiversity is a bad thing, because I find the diversity of life fascinating and for that reason I think it is something that should be preserved, however I was trying my best to keep my subjective opinions out of this topic, and attempting to stick to the question of how human activity is affecting diversity, rather than whether it is good or not.

I think it's a matter of degree, rather than a case of never before.

Early human colonization of the world undoubtedly brought flora and fauna with it - the colonization of Polynesia, or America over the Bering Strait and from Europe, for example.

Modern international trade and travel just increases the degree of this spread of flora and fauna to new ecosystems.

Kindest regards,

James

 

[Dean]

WarK

["¦] That isn't what I meant, I know that ecosystems will not be destroyed for good, my point is that we have a penchant for introducing alien species to areas can turn an ecosystem on its head.

You could look at it from different perspective. Those species use us to travel and conquer new ecosystems. ["¦]

["¦] A more interesting point is that we're the first species able to directly tweak genetic make-up of other species and how this could impact evolution.

• "Those species use us to travel and conquer new ecosystems."

A very subjective valuation in my opinion, and not a particularly useful one. As I've said before, Homo S Sapiens, in the long run does indeed act as a kind of 'pest' on the rest of the biosphere, not only devouring life in a sui-genocidal manner, but also introducing alien-species around the world in habitats they've never experienced before, and then those ecosystems that have been invaded, suffer the consequences, as they did in Australia. Of course, evolution has no agenda, but it's pretty hard to argue that these effects of humanity haven't altered the course of evolution, albeit they usually weren't intended to ...

Of course, you might well be tempted to phrase it in terms of evolutionary "parasitism" as it is sometimes called, e.g. a genuine example of this process would be the life cycle of Neoneurus vesculus, e.g. parasitoid wasps et al. A more prudent example might be plant-species that have evolved to become trapped on animal skins, and then those animals transport them , or their seeds, usually , to an alternative location, to grow. Perhaps you could say that this applies on a grander scale, for example, Homo S Sapiens. introduced rats to the islands of Mauritius and New Zealand, with drastic consequences for the bird-species there, e.g. the Giant Moa, and,in the case of Mauritius; the Dodo.

That would be a classic example of the kind of "turning of an ecosystem on its head" that Laurens referred to in his earlier post, but to classify this relationship as a form of parasitism on behalf of the non-human animals is wrong. It is a metaphor at best, and not necessarily the best one. If anything, it is we who are the parasites on the biosphere, particularly on the species we've domesticated, and the species that we are constantly wiping out, as whiney as that might sound. But the point is still valid.

• "A more interesting point is that we're the first species able to directly tweak genetic make-up of other species and how this could impact evolution."

What the hell do you mean by "directly" anyhow? Surely the molecule of DNA 'directly' modifies itself to within a few nucleotides every time an individual organism reproduces...? The "copying" of DNA is never perfect, albeit the changes are always rather minute in one generation, and sometimes , be it rarely , it can have both beneficial and detrimental consequences to the descendents of those organisms in the long run. And isn't natural selection "directly tweaking" the genetic-make-up of organisms? After all, it's produced humans, lions, and zebras, in the space of a few billion years, which despite its slow rate, is vastly more powerful than any organisms human beings have been able to fiddle with.

One grain of sand, in a whole beach of time, has been spent by human beings, "directly" modifying the phenotypes of the animals we have come to domesticate, such as cattle and dogs. In the time scale of Evolution, we've barely scratched the surface, and probably never will. We have artificially engineered, a.k.a. "selected" outlandish forms of cattle (among other things), to produce bizarre forms such as the Belgian Blue ... but most of these changes are often accidental, e.g in the case of our domestication of cats, there are cats that occurred in the past as genetic "freaks", like a single bald kitten born in the 1960s lead to the Sphinx breed. The changes that "we" claim to make are often accidental, sometimes more than they are deliberate.

You might well say, that transgenics and biotechnology qualify as 'directly' modifying organisms' genetic make-up. But the chances that the slight changes we have made will have a noticeable impact on evolution is wrong. Even if strains of, e.g. new crops escaped into the wild, and interbred with the "natural" crops that were in the vicinity, all trace of their existence could well disappear within 10-12 generations. If you're talking about more drastic changes ... organisms that are direct hybridizations of other organisms are almost universally sterile, thus they can't breed, and if they were released it would thus have zero effect; on the evolution of their ancestral phenotype organisms, e.g. say we were interbreeding lions with tigers (which has been done by the way).

Laurens

["¦] My main point is that this has never happened before in the history of life, and this has undoubtedly changed the game of evolution to some extent.

I never really made any explicit judgement as to whether this is good or bad, although I guess my use of terms such as 'wreaking havoc' might have given a hint of negativity. ["¦]

It has indeed wreaked havoc. And it still is, with increasing severity. But few people seem to give a damn about sentient life these days, neither in fact, nor fiction, as we can see in the climate-change "debate". And yes, it seems clearly that the introduction of alien species worldwide will alter the ecosystems in those areas per se. But there have been instances of such events occurring with rather disturbing consequences, e.g. as in the case of the Dodo.

I feel that you would perhaps enjoy this discussion:

• The Darwin Debate
  

This was aired towards midnight on New Years Eve 2010. It was a damn side more interesting than watching Alan Carr, I'll tell you. As the host of the debate intones "To what extent are we still under the shadow of Natural Selection?". An intriguing discussion, except it's more to do with how evolution is affecting us, rather than vice versa. But still fascinating.

I have posted it before. The discussion is between Jonathan Miller, Meredith Small, Steven Pinker, and Steve Jones. To varying degrees, I align with Small and Jones, heh.

It strikes me that this debate is more to do with the human cultural changes, e.g. sexuality and so on, but it is relevant, in that it discusses the issue of human-impact on evolution, how we might have changed it, and ultimately how it will adversely effect us. I wish it went on for longer than it did.