So my understanding of evolution was that Natural Selection worked at the species level with epithets like “survival of the fittest”. These seemed to imply a competition amongst species rather than cooperation.
Of course, one may argue that the survival of the ecology in the long term means the survival of the individual species, but is this really the case ?
I draw a parallel to the scientific theories in economics where about 30 years back, it was assumed that humans were rational economic decision makers and philanthropic giving was unexplained to the current theories of behavioral economics.
So is there a revision or change in understanding of how evolution works at the species and ecology level ?
Natural selection happens at the level of the individual organism. Some go even further to say that it happens on the level of the individual gene.
Nope. The article is somewhat misleading. It isn’t trees transferring nutrients to other trees. It is fungi transferring nutrients to other trees. It is advantageous to the trees to share nutrients with the fungi, and advantageous to the fungi to keep the trees healthy. It is pure self-interest. Probably doesn’t even raise to the level of being called reciprocal altruism.
Not in general. We’re pretty good at killing other species for food or a variety of other reasons. There are some great examples of benevolence towards species we find especially cute/adorable, but that’s not something that applies well to all other species.
Not really - species is a human category imposed on nature, not really a unit that natural selection can work on - ring species are an example of how that doesn’t really work the way we’d like to think.
Natural selection works on the level of individual organisms - which organism survives/which dies? Which reproduces/which doesn’t?
But there are mechanisms of evolution that act on other levels of organization - environmental changes affect entire populations, kin selection operates on groups of common lineage, other mechanisms act on the population level, like the founder’s effect.
“The ecology” - do you mean the species’ survival is dependent on the survival of its environment? That’s a little too vague - think about the case of invasive species, which are taken out of their environment and thrive. Also think of mass extinctions, where drastic changes in the environment wipe out large numbers of species. In some cases changes in the environment can be beneficial to a species, and in other cases changes can be harmful.
I don’t think so - it’s not really incompatible with evolutionary theory.
Individuals do not evolve, interbreeding populations evolve. Evolution is the change in gene frequency within an interbreeding population, WITHIN a species. So the competition that’s relevant to natural selection is the competition between individuals (organisms or genes) WITHIN a species. To the extent that there is competition between species, species B is simply part of the environment of species A, affecting the kind of selection pressure that individuals within species A will experience as they compete with one another (and vice versa). For example, if many plant species are competing intensely for light, that may create an environment with strong selection pressure to grow tall. But natural selection occurs WITHIN one of those species because the environment they live in (including the other species) means that the taller of two individuals WITHIN that species is more likely to pass on its gene variants to the next generation of that species.
If I understand the question correctly, and I am not very sure that I do, I would think that evolution works on all the possible levels.
Evolution is not just when individuals who are better fit are more likely to pass on their genes.
In the level of small groups, those groups who contain individuals who cooperate better (even if say they get social anxiety to prevent them for fighting for leadership positions, thus making the individual less fit) are more likely to survive when fighting other groups who cooperate less. Thus cooperative genes are passed on, despite them not being an advantage for the individual.
Even in the planetary level, aliens are less likely to be super aggressive, because all the planets where they did not evolve to become less aggressive as they got access to better weapons would be self destroyed.
Actually, no, it doesn’t. Evolution by natural selection, the process by which complex highly adapted organisms arose, operates almost exclusively through competition among individuals. The arguments against group selection are rather technical and mathematical, but essentially individuals within a group “cheat”, undermining the group dynamic. It’s somewhat counterintuitive, I’m on my phone but ref the extensive Wiki article on group selection for the history of the debate. EO Wilson tried to revive group selection recently but was widely panned.
Above the species level, it’s obviously still true that the tautology “things that survive survive”, but that’s not particularly interesting when it’s just a question of whether something goes extinct or not, when there is no mechanism for the accumulated change in a genetic system that allows populations to evolve complex adaptations. Adaptation only occurs through competition between individuals within an interbreeding population, leading to the differential survival of gene variants within that population.
Not really - there are a few levels where we can identify specific mechanisms that create the large-scale changes in gene frequency that is evolution, but there are other levels where this doesn’t really apply well. Upthread I mentioned ring species, which are a good way of getting a handle on the idea that humans like to fix a label of ‘species’ on categories of organisms, but where we like to put a black-and-white line, nature actually works in shades of grey. Because of this fuzziness, it’s hard to credibly claim that selection mechanisms work on the level of species as a unit.
I think this is a little too abstract for a good discussion of group selection - it seems to rely on some hand-waving about evolutionary psychology that I don’t think is well-supported.
This is definitely too speculative to be taken seriously - we are in the General Questions forum, where we’d like answers to be a little more grounded in observable phenomena.
The tree competition model, you stated, is what I grew up learning too. But Ecologist Suzanne Simard from Yale says “They compete with each other, but our work shows that they also cooperate with each other by sending nutrients and carbon back and forth through their mycorrhizal networks.”. Link - Exploring How and Why Trees ‘Talk’ to Each Other - Yale E360
Evolution comes down to a simple maxim - whatever genetic trait helps you survive to reproduce, gets passed on. The more that survive because of that trait, the more have it in following generations.
There have been arguments for “good Samaritan” genes. Presumably, in a collective (tribe, group) as humans used to be until agriculture, being willing to sacrifice to help the collective when appropriate helped your genetic material survive in your immediate relatives that were part of the group. There have been assorted studies, IIRC, that showed the effect is more obvious when the beneficiaries are closer relatives, but in our extended societies, people will sometimes help complete strangers.
You can also argue a genetic predisposition to have some group members “alpha” and some more submissive helps the group dynamic work properly. If too many people contest the hierarchy, a group descends into chaos which is good for nobody.
But ultimately, it’s every organism for themselves.
I was reading about a species of frog that is almost exclusively cannibalistic. The tad poles generate enough nutrients from micro organisms and plankton to sustain a population that feeds off of one another. Hard to imagine any reason for something like this beyond the fact that it seems to work.
I’m not really sure what you think the issue is. Do you think the discovery of cooperation for mutual benefit among plants somehow means we need to rethink evolution? Why? Sophisticated cooperative strategies among animals that go far beyond nutrient exchange have evolved:
It sounds like Dr Simard is buying into some kind of Gaia hypothesis here:
Exactly - a certain level of altruism within a species, as long as a significant number of the species observe it, can be beneficial for the species and hence for any members. OTOH, it could evolve as just a reinforcement of a distress indicator. A troop of monkeys or whatever - does one need to raise the alarm to survive when it sees a threat? Probably not, but monkeys and many other species scream when they think they see a threat, and while under attack. Chemical warnings by trees in distress could simply be a similar process; the ones in distress provide enough chemical alert to allow nearby trees to prepare whatever defenses they have against the same threat - moving at the speed of plants.