Biopsychology: Nature vs Nurture?

[Moogled]

Hey guys, here's a quick blog that I wrote when I started thinking about genetics vs experiences (or a combination of both). Dieting behaviours are a big issue nowadays and discussion about how some physical changes are predispositioned and others are chaped have come up.

Serious comments (hopefully with good written skills) are extremely welcomed and appreciated:


In this 21st century, our wealth of information has grown beyond knowing what a body does. We have substances to work with biological processes knowing that irregularities can be controlled; much like how insulin is used to treat diabetes. Even normative processes such as "fast/slow" metabolism are further debunked. Bodybuilders make use of protein synthesis knowledge and ephedrine cycles in order to facilitate their gains.

It would be too bold to say that armed with knowledge and experience about biology, that you're set for life. Using findings from anthropology, it's been found that many earlier Homo sapiens have extremely lean and fit bodies due to their diet and lifestyle. Much like how many of you have stated, proper eating habits and lifestyle, supplemented by knowledge of bodily processes, can certainly counteract many (not all) biological predispositions.

But you know what else I think? For all the talk about understanding biology and how genetic predispositions have an effect, I've never seen any mention of an obese Homo erectus and/or early Homo sapien. We're talking about a people that needed to chase prey for 5 days before trying to kill it with sticks and stones. I think that civilization has procured indulgement in our lives to the extent that we were given the opportunity to drive while eating donuts, and offering an officer one when we get pulled over. That said, the advent of modern man has also allowed us to pass genes down throughout generations. With much of medical care and technology undermining "natural selection", it's no wonder that pretty much ANY genetic/hereditary inheritance is possible.

Let me put this into perspective:

There are more than 60 million obese adults in the US - how many of them do you think abstain from sex?

[Pan]

EDIT REASON: Changed my mind on something, will post later...have to think about something

[Todd]

I would say that this is a flawed argument based on one major fact: It is not the acquired traits (physiological ones, such as a lean body or large pectoral muscles, or an obese body) that is passed on, but rather then inherited genetics (ability to have a lean body, large pectoral muscles or an obese body). Thus Natural Selection, should not be oversimplified and viewed at the individual level as the 'survival of the fittest' , but rather a long process that favors subsections of a species with superior inherited traits (or mutated genes for that matter); allowing over time, differentiation of this sub sect.

When this is considered your argument becomes invalid. You agree to this in your premise:

it's been found that many earlier Homo sapiens have extremely lean and fit bodies due to their diet and lifestyle. Much like how many of you have stated, proper eating habits and lifestyle, supplemented by knowledge of bodily processes, can certainly counteract many (not all) biological predispositions.

You are agreeing that diet and lifestyle affect physiology, and that genetics (biological predispositions), play little role in determining body composition.

[justinl]

In this 21st century, our wealth of information has grown beyond knowing what a body does.

well first of all, Id just like to say that we have no freakin idea how the majority of our body functions work.

Using findings from anthropology, it's been found that many earlier Homo sapiens have extremely lean and fit bodies due to their diet and lifestyle.

diet and lifestyle does not affect skeletal structure (which is virtually all you find really, and almost never a complete set), so I don't know where you got the proof behind no obese early hominids. That and, you have to realize that given all the living creatures on the planet, and all their possible fates, being fossilised is a ridiculously remote event. There is no way any fossil record could ever give an overview of any given population (human or otherwise) to support that claim.

although, fwiw, i dont think there were as many obese people then as there are now, I just disagree with the unsupported assumption that there were none.

But past that, I do see your main point (even if the main argument is a bit muddled). Our society thrives on a litany of excess that includes much more than just food. It's ridiculous to the point of madness and Im convinced that eventually we'll choke ourselves to death on it one way or another.

With much of medical care and technology undermining "natural selection", it's no wonder that pretty much ANY genetic/hereditary inheritance is possible.

Well, actually the event passing of genetic information and natural selection are pretty distinct. Whether natural selection is present or not, genes will be passed on (given the organisms aren't extinct of course). I think the term you're looking for is artificial selection; human induced selection. It's the same as what we did to breed species of dogs to be domestic pets that never existed in the wild.

[Moogled]

Hey guys, thanks for the excellent replies. You both make valid points, but there's something that I'd like to clarify:

I'm not making an argument/claim for either side. Rather, it's more about exploring whether or not there's a wholesome argument in that dieting behaviour can be attributed to 21st century advancements or if there are factors only affected by nature.

Furthermore, the bulk of my speculation lies in the interaction between the advent of civilization as modern man and our physiology. It's not that we inherit skeletal structures as much as it is a propensity towards a certain body type.

That said, my reference to natural selection means refers to the possiblity that medical technology and a modern healthcare system reduce mortality rates, giving any traits/genes an opportunity to be passed down to generations (e.g., genetic predispositions).

The reason my example of early hominid lifestyle/diet overlaps with modern Homo sapien genetics is due to the transition from bumbling neanderthals over the generations; that is, any of the aforementioned technological advancements. Natural selection was more relevant in the past but as sophisticated modern man, we now have the means to keep vegetative persons functioning and 2 pound babies alive through machines.

What are the implications about our ancestors and our current understanding according to nature/nurture?