A grab-bag of biological questions.

[Janitor]

No one of these questions by itself is worth starting a thread over. But maybe collectively they amount to a modest-sized hill of beans...

1. I knew someone who claimed that the expression "fell and broke her hip" is putting it backward. He said an elderly person who is walking suffers a sudden fracture at the hip joint, and the resulting inability to support the body properly on just the one remaining good leg topples the person onto the floor. Is he onto something?

2. Some vegetarians give the impression that vegetables are a guilt-free source of food. But I know a person who says that is certainly not the case, and he points to nuts and avocadoes as examples of foods that are high in fats and that can make you obese. True?

3. Sometimes when I am lying in bed, almost asleep, one of my legs will suddenly bend at the knee and jerk upward. Somewhere I read that this is a leftover reflex from when our ancestors were tree dwellers, and they needed to be able to react almost instantly when slipping off of a tree branch at night as they slept. Is this plausible?

4. Years ago I read a book or an article (don't remember which) that put forward the idea that humans are "aquatic apes." By this, the author meant that more than other primates, our ancestors spent a lot of time in the water. Supposed evidence for this was women's abillty to grow really long hair so that the infant could grasp its mother's hair with its fingers and thereby keep its head above water, and that our body's hair shafts are slanted in such a way that as we swim, the tail end of the hairs are already pointed in the downstream direction, the resulting streamlining allowing us lower muscular effort when we swim. No doubt other evidence was presented as well, but those are the two things I can recall. Has anybody heard of this?

 

[iansmith]

2. Some vegetarians give the impression that vegetables are a guilt-free source of food. But I know a person who says that is certainly not the case, and he points to nuts and avocadoes as examples of foods that are high in fats and that can make you obese. True?

Nuts and avocadoes have high level of unsaturated fats. Fat alone does not make your overweight, it is your calories intakes that will influence your body weight. I have never seen an overweight vegetarian, except those that were already fat before becoming vegetarians. These people did not lose a lot of weight on that type of diet but they did not gain any pound. The good point with fruit, vegetable and nuts is the high fiber content which fills you up and hence you intake a more reasonable amount of calories.

4. Years ago I read a book or an article (don't remember which) that put forward the idea that humans are "aquatic apes." By this, the author meant that more than other primates, our ancestors spent a lot of time in the water. Supposed evidence for this was women's abillty to grow really long hair so that the infant could grasp its mother's hair with its fingers and thereby keep its head above water, and that our body's hair shafts are slanted in such a way that as we swim, the tail end of the hairs are already pointed in the downstream direction, the resulting streamlining allowing us lower muscular effort when we swim. No doubt other evidence was presented as well, but those are the two things I can recall. Has anybody heard of this?

I heard about this theory on TV. There is also the fact that infant can intuitively swim and control their breathing under water until the age of about 4 to 6 month.

This page discuss most of physiological adaptation that may have evolve from living in acquatic environment.
http://www.primitivism.com/aquatic-ape.htm
There is some good and interrresting point but some points (Ventro-ventral copulation and Skin-bonded fat deposits) could be argue easily and possibly be dismiss has they are not as solid as it seens.

 

[Chemicalsuperfreak]

1. Even with advanced osteoperosis, it still takes some degree of force to break a hip. My bet is that 99 times out of a hundred the hip breaks from the force of the impact with the floor. Although I'm no MD.

2. There are many fats in vegetarian foods. And there are plenty of obese vegetarians. That said, I'd bet vegetarians are less likely to be obese than others.

3. Plausible, but there's no evidence for it.

4. There's a lot of speculation that humans evolved by the sea. Although there's better reasons for the idea than the ones you've given, men and women can both grow long hair just fine. But like above, it's a perfectly decent hypothesis, there's just no evidence to support it.

 

[Janitor]

Thanks to the both of you for the responses. I was not able to remember the supposed timing of the aquatic phase, but the link given above says: "The Aquatic phase took place more than 5 million years ago. Since then, Homo has had five million years to re-adapt to terrestrial life. It is not surprising that the traces of aquatic adaptation have become partially obliterated and have gone unrecognized for so long."

 

[aychamo]

Regarding the broken hips, your question has the correct answer. My father is an orthopedic surgeon and verified this. When walking, you place a lot of stress on the femurs. If they step wrong, or whatever, an osteoporotic person's hip will break, and then they fall down. The people tend to think that they break their hip when they fall, but it is actually broken first, and that is what causes them to fall.

(This is not to say that all broken hips happen before falling down, just the vast majority are in respect to osteoporotic people)

Imagine that pain :) You are just walking and your damn hip breaks!

Regarding #2 and #4, check out the newsgroup talk.origins , they have some knowledgeable people over there regarding such things!

 

[Janitor]

Aychamo, your source on hip breaking certainly has the credentials. Ain't no surgeons living in my neighborhood!

 

[zoobyshoe]

Aychamo, your source on hip breaking certainly has the credentials. Ain't no surgeons living in my neighborhood!

This is exactly how my grandmother broke her hip. She stood up from sitting, her hip broke, and she fell down.

The leg jerk is what's called a myoclonus. Fancy medical term for a spasm in a muscle or group of muscles. It's generated in the brain. It's pointless and not a leftover trait. Caused by a little chemical unbalance, maybe from something you ate that day or whatever.

I saw a show on TV in the past year or so about the discovery of a species of gorilla in the inner, hidden reaches of the Congo that spends most of the day submerged up to their necks in the rivers. They don't know enough about them to be sure why they do it. To keep cool? To keep bugs off? Other species of gorilla seem to be afraid of the water, they said. They had a lot of footage of them. There's also a species of babboon or macaque type thingy on the island of Hokaido north of Japan that spends lots of time in these hot springs they have there. They call them snow monkeys. National Geographic had a cover article about them years ago.

 

[Janitor]

Zoobyshoe, I remember that National Geographic cover. And I hope the Congo does not have crocodiles!

Caused by a little chemical unbalance, maybe from something you ate that day or whatever.- zoobyshoe

Man, I got to cool it with the orange juice & chocolate combination.