Perhaps This Explains Theism?

[Minimalist]

http://www.sciencedaily.com/releases/201...141537.htm

"This research indicates that what drove the evolutionary expansion of the human brain may well be a specific unit within a protein -- called a protein domain -- that is far more numerous in humans than other species."

The protein domain at issue is DUF1220. Humans have more than 270 copies of DUF1220 encoded in the genome, far more than other species. The closer a species is to humans, the more copies of DUF1220 show up. Chimpanzees have the next highest number, 125. Gorillas have 99, marmosets 30 and mice just one. "The one over-riding theme that we saw repeatedly was that the more copies of DUF1220 in the genome, the bigger the brain. And this held true whether we looked at different species or within the human population."

[Mister Agenda]

Verrry interesting. Though I think it's more than just big brains that account for theism, no doubt it's a prerequisite.

[Humesapprentice]

I don't see how this finding would "account" for theism. Just because humans are (a) the only species who believe in God as far as we know and (b) the only species that has X amount of Protein Y does not mean that (b) caused (a) or vice versa. There might be a connection, but sure can't tell that that's the case from the findings so far.

[Angrboda]

I don't have time to read the detail tonight, but a couple of questions do come to mind prior to reading it. One is, in what way is this any different than the general principle of "genetic clocks" in which the farther you go away from a species, in terms of last common ancestor, the less genetic material they have in comon; how is this specific marker unique against the general background pattern of diverging genomes. Second, and I'm not asking you, but one thing has bothered me this past year about claims regarding the rapid increase in brain size in the hominids leading up to and including homo sapiens sapiens. The general theory of "intelligence" from what I recall, correlates ratio of the logarithm of the brain volume to the body mass, or some such. I've probably got the formula wrong, but the thrust is that intelligence is a function of a ratio of brain size to body size, not of absolute brain size. Now, it's true that hominid brain size was increasing, but hominid body size was also increasing at the same time, and since relative intelligence is a function of the ratio, you have to adjust for the increase in body size for a realistic appraisal of when our "animal intelligence" was increasing, and by how much. I haven't looked real hard, but I've never encountered any attempt to chart hominid intelligence per this maxim of general animal intelligence. (Which may itself be invalidated by more recent studies in animal intelligence than I've read — I'm not very current on the literature — but I think, at minimum, it would provide a more realistic appraisal of the upcurve of intelligence in the evolution of the hominids.)

[pgrimes15]

This study suggests that the DUF1220 may be the cause of evolution of brain size.
I think that a question equally if not more fascinating is why this mutation (increased brain size) gave enough survival advantage that it propagated through the generations.
Some have suggested that, in the hunter-gatherer world of our distant ancestors a larger brain size gave an individual an advantage in a highly social animal, perhaps using rudimentary language. In other words, smarter hominids were better at "chatting up" cave-women and so spread their genes. This would make the large brain a sort of "peacocks tail" with, at that time, no other purpose (yes I know evolution has no "purpose" but you know what I mean).
Agriculture, animal husbandry, writing, technology, etc. could all be just unforseeable side effects of this "peacocks tail".

We may never know what the truth of these matters are unless someone invents a time machine, but I like the idea of chatting up cave women. That's my regular Saturday night.

Regards

Grimesy

[Cinjin]

Min, they should study the reduction and decline of DUF1220 upon subliminal acceptance of earthbound deities, their associates and all things derived from old dirty pieces of bronze age paper.


some evidence that these studies may already be underway:

[Angrboda]

This study suggests that the DUF1220 may be the cause of evolution of brain size.
I think that a question equally if not more fascinating is why this mutation (increased brain size) gave enough survival advantage that it propagated through the generations.
Some have suggested that, in the hunter-gatherer world of our distant ancestors a larger brain size gave an individual an advantage in a highly social animal, perhaps using rudimentary language. In other words, smarter hominids were better at "chatting up" cave-women and so spread their genes. This would make the large brain a sort of "peacocks tail" with, at that time, no other purpose (yes I know evolution has no "purpose" but you know what I mean).
Agriculture, animal husbandry, writing, technology, etc. could all be just unforseeable side effects of this "peacocks tail".

Another aspect that I've heard, but don't have exact details on, happened somewhere in the 2-6 Mya time frame. During that time, Africa was undergoing significant climate instability, and the constant abrupt changes in climate served as a sieve for selecting out the most intelligent of the species.

[Anomalocaris]

In order for a theory to convincingly explain why large brains evolved in hominid ancestors, it needs to offer an non-trivial explanation for why similar brain enlargement did not confer enough advantage to evolve in other animals.

Currently most theories aim largely at appearing to arrive at where it wants to go, that human evolved large brains, but give only casual, sometimes flippant, glance at the equally important validation - why large brain did not evolve more frequently elsewhere.

---

As it happens, I think evidence point to indirect realation between brain size and behavioral complexity. Large brain is costly to maintain. If small brain can do the trick of conferring the needed cognative power and behavior sophistication, large brain is an evolutionary burden, not advantage.

Is small brain enough? Apparently yes. Homo flourensis exhibit evidence of equal sophistication in stone tools as homo erectus. Yet it's brain size would embarrass a chimpanzee. So a brain even aller than those of a chimp can support behavior and cognition of a high order. So why the profligacy of a big brain.

[pgrimes15]

Another aspect that I've heard, but don't have exact details on, happened somewhere in the 2-6 Mya time frame. During that time, Africa was undergoing significant climate instability, and the constant abrupt changes in climate served as a sieve for selecting out the most intelligent of the species.

It is not apparent to me how intelligence manifests itself in a primitive population of hominids. The kind of intelligence we mean in the modern world - cleverness at school, thrusting ambition at work - surely needs the framework of developed societies to become visible. The climate change in ancient Africa would seem to me more a sieve for selecting the physically hardiest members of a species.
We may never know but it is fascinating to speculate.

Regards

Grimesy

[Angrboda]

In order for a theory to convincingly explain why large brains evolved in hominid ancestors, it needs to offer an non-trivial explanation for why similar brain enlargement did not confer enough advantage to evolve in other animals.

Currently most theories aim largely at appearing to arrive at where it wants to go, that human evolved large brains, but give only casual, sometimes flippant, glance at the equally important validation - why large brain did not evolve more frequently elsewhere.

---

As it happens, I think evidence point to indirect realation between brain size and behavioral complexity. Large brain is costly to maintain. If small brain can do the trick of conferring the needed cognative power and behavior sophistication, large brain is an evolutionary burden, not advantage.

Is small brain enough? Apparently yes. Homo flourensis exhibit evidence of equal sophistication in stone tools as homo erectus. Yet it's brain size would embarrass a chimpanzee. So a brain even aller than those of a chimp can support behavior and cognition of a high order. So why the profligacy of a big brain.

Just off the top of my head, one could argue that big brains, and specifically the skills that came with them, allowed hominids to exploit an ecological niche which was unavailable to other species for whatever reason (bipedalism, opposable thumbs [homo habilis?], lack of other skills versus competitors). This is all very post hoc, but I don't think it would be a stretch to imagine a just-so story that explains it, and there appears to be circumstantial evidence for it in the extinction of hominid species in Eurasia following the migration of homo sapiens into the area (presuming the late migration theory). Quite simply, large brains aren't as big a selection advantage for most animals, particularly highly capable predators, and herbivores.

Oh, and re: flourensis, the habitat of flourensis was considerably different from Africa and Eurasia, so even adjusted for size, it's unclear that they were competitively intelligent with a hominid that evolved in a less evolutionarily isolated environment like that on an Indonesian island, such as habilis or sapiens. Moreover, if they evolved down, as it were, there's a totally different selection process occurring.