Register to reply

Suicide and Evolution

by Tungamirai
Tags: evolution, species, suicide
Share this thread:
ViewsofMars
#19
Aug8-11, 07:35 PM
P: 463
Quote Quote by arildno View Post
My view is:
Evolutionary theory can legitimately be challenged to provide answers to those traits that are HIGHLY frequent/universal, but there are no reason whatsoever why weird&infrequent behaviour in any way ought to be explained by it.
Just my two cents..
Thanks for joining the conversation Arildno. What do you consider to be weird and infrequent behavior?

Here is an abstract from a larger document pertaining to behavior:
“Referential models based on extant African apes have dominated reconstructions of early human evolution since Darwin’s time. These models visualize fundamental human behaviors as intensifications of behaviors observed in living chimpanzees and/or gorillas (for instance, upright feeding, male dominance displays, tool use, culture, hunting, and warfare). Ardipithecus essentially falsifies such models, because extant apes are highly derived relative to our last common ancestors. Moreover, uniquely derived hominid characters, especially those of locomotion and canine reduction, appear to have emerged shortly after the hominid/chimpanzee divergence. Hence, Ardipithecus provides a new window through which to view our clade’s earliest evolution and its ecological context. Early hominids and extant apes are remarkably divergent in many cardinal characters. We can no longer rely on homologies with African apes for accounts of our origins and must turn instead to general evolutionary theory. A proposed adaptive suite for the emergence of Ardipithecus from the last common ancestor that we shared with chimpanzees accounts for these principal ape/human differences, as well as the marked demographic success and cognitive efflorescence of later Plio-Pleistocene hominids”: http://www.sciencemag.org/content/326/5949/74.abstract

As far as suicide is concerned, the Depression and Bipolar Support Alliance states, “The most important thing to remember about suicidal thoughts is that they are symptoms of a treatable illness associated with fluctuations in the body’s and brain’s chemistry. They are not character flaws or signs of personal weakness, nor are they conditions that will just "go away" on their own.” (1) Also, the Mayo Clinic states, “There may also be a genetic link to suicide. People who complete suicide or who have suicidal thoughts or behavior are more likely to have a family history of suicide. While more research is needed to fully understand a possible genetic component, it's thought that there may be a genetic link to impulsive behavior that could lead to suicide.” (2)

1. http://www.dbsalliance.org/site/Page...uicide_suicide

2. http://www.mayoclinic.com/health/sui...SECTION=causes

3. Just located this on suicide prevention: http://www.medicine.manchester.ac.uk..._July_2011.pdf
Constantinos
#20
Aug9-11, 02:47 AM
P: 78
I thought bees were suicidal. When trying to defend their hive from animals, they sting the animals and detach the stinger, which leads to their death. Isn't this true?
Ken Natton
#21
Aug9-11, 03:05 AM
P: 272
Quote Quote by Constantinos View Post
I thought bees were suicidal. When trying to defend their hive from animals, they sting the animals and detach the stinger, which leads to their death. Isn't this true?
No, not really. All hymenoptera have this behaviour which is what biologists mean when they use the term ‘altruism’. The bees sacrifice themselves for the greater good of the hive, and it is a behaviour that does make sense in purely Darwinian evolutionary terms, on the basis of the long term benefits of the individual bee’s genes. There are much deeper subtleties to this, the preceding is really a hopeless over simplification of the point, but for the current discussion, the point is that this is not, by any stretch of the imagination, suicide. The bees are simply engaging in a genetically programmed behaviour. They are not contemplating their own mortality and making a conscious decision to end their own life.
Constantinos
#22
Aug9-11, 03:19 AM
P: 78
Quote Quote by Ken Natton View Post
No, not really. All hymenoptera have this behaviour which is what biologists mean when they use the term ‘altruism’. The bees sacrifice themselves for the greater good of the hive, and it is a behaviour that does make sense in purely Darwinian evolutionary terms, on the basis of the long term benefits of the individual bee’s genes. There are much deeper subtleties to this, the preceding is really a hopeless over simplification of the point, but for the current discussion, the point is that this is not, by any stretch of the imagination, suicide. The bees are simply engaging in a genetically programmed behaviour. They are not contemplating their own mortality and making a conscious decision to end their own life.
Yes sorry, I missed a previous post of yours that defined suicide as such. Well then I guess no animal is capable of such a behavior. It does depend on the definition of "suicide", but I think I can agree with this particular one.
Ken Natton
#23
Aug9-11, 03:50 AM
P: 272
Yes, I hadn’t thought about it, but I suppose this is another matter of how you interpret the terminology. When I was, some time ago, involved in a discussion on another forum about altruism, the discussion degenerated into a wholly pointless argument about the definition of the term ‘altruism’. There were a whole group of contributors who wanted to argue that there is no such thing as altruism because, ultimately, all behaviour is governed by self interest. That then led to an equally irrelevant argument about human motivation and human dignity. All of which hopelessly missed the point, of course. The behaviour in hymenoptera is real and observable. It is something that, on the surface seemed to be contrary to Darwinian evolution, but after a great deal of work by some more careful thinkers, proved to be entirely compatible with Darwinian evolution. And, where it becomes interesting is when you realise that something similar does exist in other species, including humans, although there are some significant differences in how it works. One little insight into that is to realise that, while human siblings of either sex share essentially 50% of the same genes, bee sisters share 75% of the same genes with their other sisters, but only 25% of the same genes as their brothers.

In any case, the point I was driving at was that we may have a similar difference of perception of the word ‘suicide’. If suicide is simply any action which results in the loss of one’s own life, then I suppose bee behaviour is suicide. But I would suggest that generally, when we use that term in the case of humans, we are referring to a complex cognitive chain followed by the individual that led to an action whose primary purpose was the ending of their own life. That is something of which only humans are capable.


Register to reply

Related Discussions
Ecosystematic Evolution (symbiosis in the importance of evolution) Biology 5