On the Origin of Feces

[Elder Iptuous]

Kai,  do you know of any other species that have a mutual relation with another where they impede or promote selective breeding in some way?  even in some rudimentary way?

Vex,  regarding your friends rambling response....
i thought I overused ellipses!
Does the bolded statement causing confusion?  does he understand what speciation is?  would he expect all life, assuming that it arose from a common source, to change in unison for all time?

[tyrannosaurus vex]

I dunno. I just told him to shut up if he can't at least speak in complete sentences.

[Kai]

Kai,  do you know of any other species that have a mutual relation with another where they impede or promote selective breeding in some way?  even in some rudimentary way?

Yeah, lots of them. Obviously not conscious, but theres a whole field of biology devoted to studying coevolution, where two or more species engage in a selective arms race with each other. Insects and plants are the most prominent examples, where the plants are constantly being selected for by insect herbivory to produce better and better defensive chemicals and the insects are being heavily selected for by the plants to develop novel ways of avoiding those chemical defenses.

Or, think of parasites and hosts. While the parasite may not be causing selection pressures on the host, thus not being coevolution, the host is causing strong selection pressures on the parasite. Think crab lice. They have those giant claws to grasp the thick hairs in the pubic region. This adaptation is a selection force by the host.

Or, social parasites, in ant colonies. Or, really, any case where selection is being caused by living things rather than abiotic factors. Humans just go about it consciously (and unconsciously, for that matter). It's not even so much a matter of forcing the best animals to breed, but rather selecting out animals with undesirable traits. Works no different than any other type of selection, in that sense.

This is why I say humans have been doing genetic engineering for at least 12000 years.

[Elder Iptuous]

hm....
the arms race type situation seems to be pressures that cause selection set in opposition.
is there any situation, for instance, where an animal that eats a certain plant will kill off specimens that do not produce suitable fruit?  or an animal that predates on another will kill off malformed young of their prey, or something?
something that could be rudimentary shaping of the other species to make it more amenable as a food source, rather than acting passively as a selective pressure for the other to build defenses against?

[Kai]

hm....
the arms race type situation seems to be pressures that cause selection set in opposition.
is there any situation, for instance, where an animal that eats a certain plant will kill off specimens that do not produce suitable fruit?  or an animal that predates on another will kill off malformed young of their prey, or something?
something that could be rudimentary shaping of the other species to make it more amenable as a food source, rather than acting passively as a selective pressure for the other to build defenses against?

No. But if the plant depends on suitable fruit to bribe animals into spreading it's seeds then a plant without suitable fruit will be by default eliminated from the lineage.

Humans are the only species with the foresight to consciously direct selection, AFAIK.

[Elder Iptuous]

hm....
we'll have to change that with the megachickens.
teach them to corral humans and kill off the ones that aren't plump enough.
maybe just have them cue in on the ones holding comfort wipes as 'keepers'...

[tyrannosaurus vex]

Not counting the sharks with lasers on their heads.