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Evolutionary instinct is to create your own offspring, not your sister's/brother's. Why would there be an evolutionary reason to help your brother reproduce but

by hueving 10y ago

Evolutionary instinct is to create your own offspring, not your sister's/brother's. Why would there be an evolutionary reason to help your brother reproduce but not your friend.?

flomble 10y ago
Because your brother shares around 50% of your genes. Helping your brother reproduce therefore helps to propagate some of your genes. The principle behind this is that evolution operates at the level of genes, rather than individuals. I recommend Richard Dawkins' The Selfish Gene for a fuller explanation.
grzm 10y ago
J.B.S. Haldane, when asked if he would give his life to save a drowning brother, replied "No, but I would to save two brothers or eight cousins." As you share on average half your alleles with a brother and one-eighth with a cousin, Haldane was giving the number of relatives one would have to save to "break even". As quoted in Mathematical Models of Social Evolution : A Guide for the Perplexed (2007) by Richard McElreath and Robert Boyd, p. 82; https://en.wikiquote.org/wiki/J._B._S._Haldane https://en.wikiquote.org/wiki/J._B._S._Haldane This is in relation to the idea of kin selection: https://en.wikipedia.org/wiki/Kin_selection https://en.wikipedia.org/wiki/Kin_selection
int_19h 10y ago
There is no such thing as "evolutionary instinct". There are instincts that become ingrained as part of evolutionary process, and they are those instincts that correlate with genes that propagate more. Thus, the genes that you inherited from your parents may activate an instinct that will make you sacrifice yourself (or at least reduce your chances to reproduce in the future), so long as that results in a larger portion of those inherited genes in the gene pool down the line - e.g. because some of your siblings, or even more distant relatives, survived to carry them on. It's one other reason why "survival of the fittest" is really a very misleading way to put it - it's about "survival" of a particular package of genetic traits, not about survival of the species, much less individual specimen. Evolution is a game of information propagation, in which actual living beings are heavily parallelized delivery channels, information transmitted is the configuration of channels, and there's non-random noise (environment) affecting signal propagation through those channels. The "winning" configuration is likely to involve some channels that do not transmit data directly, but are dedicated to performing error correction etc for other channels, that do transmit information about the entire configuration. In fact, over time, you may even end up with a configuration that can dynamically allocate channels for error correction, if and when the noise becomes noticeable enough (i.e. environment gets more hostile), so as to not waste valuable bandwidth when it's not necessary. And then we call such things "altruism", "heroic sacrifice" etc.
kitd 10y ago
Think of an ant colony. All of them brothers or half-brothers, who will sacrifice themselves when under attack to save the gene pool.
- rarec 10y ago
  That's not entirely fair as an example, as most ants will not breed and only a select few do. If you had a queen ant risking herself or the drones to save the colony, that's a different story.
  - int_19h 10y ago
    It's actually similar, it's just that the moment of choice here - whether to sacrifice yourself for the good of the genetic line - happens before birth for those ants that will not reproduce, and is made for them by other ants. Same thing for bee workers etc. But the genes that enable this type of behavior should arise in a similar manner as part of the evolutionary process.
bitwize 10y ago
It's a hedge. In the ancestral environment, times may get tough and you might not get laid. A wildebeest could gore you when you are out on the hunt, or a disease or famine break out and greatly reduce the pool of reproductive-age women. By helping a sibling make it to the reproductive stage of their lives, you ensure that at least some of your genes get passed on.

by hueving 10y ago

Evolutionary instinct is to create your own offspring, not your sister's/brother's. Why would there be an evolutionary reason to help your brother reproduce but not your friend.?

flomble 10y ago

Because your brother shares around 50% of your genes. Helping your brother reproduce therefore helps to propagate some of your genes. The principle behind this is that evolution operates at the level of genes, rather than individuals. I recommend Richard Dawkins' The Selfish Gene for a fuller explanation.

grzm 10y ago

J.B.S. Haldane, when asked if he would give his life to save a drowning brother, replied "No, but I would to save two brothers or eight cousins." As you share on average half your alleles with a brother and one-eighth with a cousin, Haldane was giving the number of relatives one would have to save to "break even". As quoted in Mathematical Models of Social Evolution : A Guide for the Perplexed (2007) by Richard McElreath and Robert Boyd, p. 82; https://en.wikiquote.org/wiki/J._B._S._Haldane https://en.wikiquote.org/wiki/J._B._S._Haldane This is in relation to the idea of kin selection: https://en.wikipedia.org/wiki/Kin_selection https://en.wikipedia.org/wiki/Kin_selection

int_19h 10y ago

There is no such thing as "evolutionary instinct". There are instincts that become ingrained as part of evolutionary process, and they are those instincts that correlate with genes that propagate more. Thus, the genes that you inherited from your parents may activate an instinct that will make you sacrifice yourself (or at least reduce your chances to reproduce in the future), so long as that results in a larger portion of those inherited genes in the gene pool down the line - e.g. because some of your siblings, or even more distant relatives, survived to carry them on. It's one other reason why "survival of the fittest" is really a very misleading way to put it - it's about "survival" of a particular package of genetic traits, not about survival of the species, much less individual specimen. Evolution is a game of information propagation, in which actual living beings are heavily parallelized delivery channels, information transmitted is the configuration of channels, and there's non-random noise (environment) affecting signal propagation through those channels. The "winning" configuration is likely to involve some channels that do not transmit data directly, but are dedicated to performing error correction etc for other channels, that do transmit information about the entire configuration. In fact, over time, you may even end up with a configuration that can dynamically allocate channels for error correction, if and when the noise becomes noticeable enough (i.e. environment gets more hostile), so as to not waste valuable bandwidth when it's not necessary. And then we call such things "altruism", "heroic sacrifice" etc.

kitd 10y ago

Think of an ant colony. All of them brothers or half-brothers, who will sacrifice themselves when under attack to save the gene pool.

rarec 10y ago
That's not entirely fair as an example, as most ants will not breed and only a select few do. If you had a queen ant risking herself or the drones to save the colony, that's a different story.
- int_19h 10y ago
  It's actually similar, it's just that the moment of choice here - whether to sacrifice yourself for the good of the genetic line - happens before birth for those ants that will not reproduce, and is made for them by other ants. Same thing for bee workers etc. But the genes that enable this type of behavior should arise in a similar manner as part of the evolutionary process.

bitwize 10y ago

It's a hedge. In the ancestral environment, times may get tough and you might not get laid. A wildebeest could gore you when you are out on the hunt, or a disease or famine break out and greatly reduce the pool of reproductive-age women. By helping a sibling make it to the reproductive stage of their lives, you ensure that at least some of your genes get passed on.