Over the past year, NPR and ProPublica have been investigating why American mothers die in childbirth at a far higher rate than in all other developed countries.

A mother giving birth in the U.S. is about three times as likely to die as a mother in Britain and Canada.

In the course of our reporting, another disturbing statistic emerged: For every American woman who dies from childbirth, 70 nearly die. That adds up to more than 50,000 women who suffer “severe maternal morbidity” from childbirth each year, according to the Centers for Disease Control and Prevention. A patient safety group, the Alliance for Innovation on Maternal Health, came up with an even higher figure. After conducting an in-depth study of devastating complications in hospitals in four states, it put the nationwide number at around 80,000.

I’m not going into great detail about this, but I do want to make a few related salient points.

First, human, please understand that for mammals, dying during childbirth is rare. You might think not because you are, say, a farmer and have seen goats and cattle and such have trouble in childbirth. But those are domesticated animals, and it is unwise to generalized from them. Usually, the birth of offspring in a mammal is not that dangerous in and of itself (though the act may for some species attract carnivores keen on a quick snack).

Humans have trouble with childbirth because were are a) primates but b) bipedal, and evolution wasn’t planning on that situation developing and c) have enormous heads at birth. Think about it. We are accustom to seeing babies so it is hard to notice, but babies have e-freakin’-normous heads. If you can find a child under about 8 years old or so, you can demonstrate this by demanding that it try to use a finger to touch its contra-lateral shoulder by reaching over the head. Can’t be done below a certain age.

Second point: The main reason this is happening, that childbirth in the US is so much more dangerous, statistically, is that a larger number of women are having babies while being at risk. One risk is age, but the others are more directly health-related (obesity, diabetes, etc.)

I mention this because our health care system can benefit a great deal (and get much less expensive and more effective) if it deals with overall health and not just sick. If we supported health rather than merely responding to medical problems when they emerge, there would be fewer medical problems emerging.

Part of that, by the way, is we stop worshiping business and the free market. Pepsi, as a private business has every right to use any means to convince all Americans to become too sick to have a baby at age 35, in order to sell their product. Right? Well, no, that is not right.

Here is the CDC report on several maternal morbidity in the United States:

Severe Maternal Morbidity in the United States

Severe maternal morbidity (SMM) includes unexpected outcomes of labor and delivery that result in significant short- or long-term consequences to a woman’s health.1 Using the most recent list of indicators, SMM has been steadily increasing in recent years and affected more than 50,000 women in the United States in 2014. This web report updates our previous report by adding information about SMM for 2014, the most recent year for which data are available on a national level.

It is not entirely clear why SMM is increasing, but changes in the overall health of the population of women giving birth may be contributing to increases in complications. For example, increases in maternal age,2 pre-pregnancy obesity,3,4 preexisting chronic medical conditions,5,6 and cesarean delivery2,7 have been documented. The consequences of the increasing SMM prevalence, in addition to the health effects for the woman, are wide-ranging and include increased medical costs and longer hospitalization stays.8 Tracking and understanding patterns of SMM, along with developing and carrying out interventions to improve the quality of maternal care are essential to reducing SMM.

The rest of the report is HERE.

A huge, undiscovered animal lurking in the Amazon rain forest? When pigs fly, you might say.But recently, Dutch biologist Marc van Roosmalen spotted a new species of peccary–a type of large wild pig–in the Rio Aripuanã region of southeastern Brazil.The newly christened giant peccary shares few similarities with its two relatives, the white-lipped and collared peccaries, both found in the same area.[source]

width=”200″ height=”343″ />This is a very large animal, which is actually opposite expectations … we would expect the larger animal to be the one eating the lower quality food. But what really counts is total demand (body mass, roughly) of the social group, because that is the unit in which competition for food would occur.Naturally, there are fears that the peccary will be threatened by hunting, which may be on the increase in this area.About twenty years ago, roughly the time when two large mammal species were discovered in Viet Nam, it was actually possible to demonstrate that the rate of new mammal species being discovered per decade was steady, not declining, for about a hundred years or so. But now, my impression is that it is not declining. But clearly, it is not zero!

The truly amazing thing about those posters is that the people in them more often than not seem to have an ethnic identity that I, as a trained Biological Anthropologist (and thus keeper of this sort of knowledge) can easily see contraindicates milk consumption. Most of these individuals would likely be unable to break down the lactose in the milk because they have the “wild type” or “normal” allele that facilitates the shutdown of lactase production some time in early life.

Now let’s be clear about this. We humans are mammals, and as mammals, we drink mother’s milk while young. This is facilitated by the production of lactase, an enzyme that breaks down the main energy bearing molecule in milk, the sugar lactose. But your basic well adapted mammals should not bother producing the enzyme lactase after weaning normally occurs … maybe a few years after in a long-lived mammal like humans … because it is inefficient and potentially risky to produce enzymes you don’t need.

Why is it inefficient? Well, there are thousands and thousands of enzymes and if we just produced all of them all the time in all our cells, that would be really costly of raw materials and energy, both of which are required to produce them. So, evolution has shaped, via the brilliant designer of Natural Selection, our multicellular bodies to produce enzymes only in the cells they are needed in (from which they may be exuded on occasion, as is the case with lactase, a digestive enzyme). This is much more efficient. By extension, the system should be (and usually is) selected to produce specific enzymes when they are needed instead of all the time from birth to death. By doing this we save a lot of raw materials and energy.

Why is there a risk of producing an enzyme when it is not needed (beyond the risk that comes with wastefulness)? This is because enzymes are the sharp objects … the scissors, the razor blades, the Jarts … of the cell. They are highly bioactive molecules that are supposed to do a certain thing but when they to fall into the wrong hands … who knows what would happen. You’ll poke your eye out running around with an enzyme.

Lactase has no special privilege. It shouldn’t be operating in adult mammals, and I’d bet it generally is not (though I don’t think very many mammals have been checked for this, frankly.)

So if lactase production in adult mammals is weird and unexpected, then why do adult humans produce it? Well, the simple answer to that is THEY DON’T. The vast majority of people by count (numbers of people), by ethnicity (numbers of ethnic groups) by cultures (i.e., numbers of languages, numbers of traditions, etc. etc.) simply don’t. Only a few groups do.

So why do we consider “lactose intolerance” a disease, rather than thinking of “adult lactase production” or “adult lactose fixation” or even “mature nursing on cow juice” to be strange instead of the other way around?

Well, we don’t do that either, I would guess. The inability to digest the lactose in milk is probably not considered at all strange by the average Chinese person, and there are more average Chinese persons than any other single group. It’s a Western thing, mainly. Just another example of Eurocentrism.

There are two main groups of people with this mutation … the adult lactase production mutation …. many (but not all) Europeans, and some (but not many) Africans.

These two groups are associated with a fairly long history of herding cattle and using dairy products from those cattle. Interestingly, some of the most famous cattle herders, such as the Maasai and similar groups in Africa, do not produce lactase in adulthood. They simply process the milk in a way that breaks down the lactose prior to ingestion.

One of the questions surrounding this observation has always been, which came first, the ability to digest milk, or the need to adapt to digesting milk, in adulthood?

I cannot imagine why such a stupid question has always been asked. Maybe because the people asking it are archaeologists instead of biologists (but that is not entirely true) or because they are anti-adaptationists (or, self styled as anti-panglossianists? Well, thank you Stephen Gould for mucking up our thinking on this one …). This is a dumb question because it is probably very rare indeed that an adaptation to NOTHING arises and then the thing to which this adaptation is adapted to comes along and fits the species. Right… survival of the fittest … ah .. niche. I don’t think so.

But nonetheless this has been a question and it now has a preliminary answer:

Joachim Burger of the University of Mainz, Germany, and colleagues worked with Mark Thomas of University College London, UK, to address this riddle by studying DNA from skeletons scattered throughout Europe. The team examined ten skeletons ranging in age from 3,800 to nearly 6,000 years old. The skeletons were discovered at archaeological sites in Germany, Hungary, Poland and Lithuania.

Cool. They conclude that the adaptation post dates the date they believe cattle were being raised by these people.

Burger and his colleagues say this supports the dominant theory on how milk drinking evolved — that milk-drinking mutations were uncommon before the practice of dairying began. Then, when humans learned to herd cattle, the milk-drinking mutations spread rapidly, because they conferred a huge advantage on those who had them — perhaps due to the extra protein and fats available in cow’s milk, the team speculates.

This is in the current issue (or forthcoming depending on when you read this) of PNAS, and is summarized nicely in Nature News.

The evolution of human diet followed a major zig (as in zig-zag) in a wholly unexpected direction, followed by the most significant biological innovation to ever occur among multi celled animals: The invention of cooking. I’m actually going to point you to two papers on this topic, and provide a brief summary of the ideas here.

Let’s start with the bold assumption that humans evolved from a chimpanzee-like animal. This is tantamount to saying that the last common ancestor of chimpanzees and humans was, essentially, pretty much like a chimpanzee. At another time, I’ll write a post on why this is a good assumption, but for now lets just go with it. Some large percentage of human evolution experts like this assumption, a bunch of others hate it (which is the usual pattern for most ideas in human evolution).

A mammal’s diet is reflected in physiological attributes that can be discerned from the fossil record. Body size, the nature of the teeth and associated muscles, possibly the shape of the mouth’s cavity, and even the overall size and shape of the gut may be closely connected with diet.

If we draw a direct line from a presumed chimpanzee-like ancestor to modern humans, we can make some inference about dietary changes by looking at these features. Chimp and human teeth are fairly different at first glance. Chimps have large canines, which could influence chewing, but let’s ignore that for now and assume that the loss of fighting canines is related to something else. The shape of the tooth row is different, with Chimps’ molars being roughly parallel, while human teeth form a more continuous arc. That probably has noting to do with diet and more to do with the canines and their use in a somewhat elongated snout (and some changes in human skulls). Chimp teeth are relatively thin on enamel and they are not especially high-cusped or large. This is not too different from human teeth. In other words, it is hard to look at the molars of chimps and humans and speculate about huge differences. The incisors of chimps are very large compared to humans, and that is likely to be a dietary difference. The large incisors are thought to be useful in processing fruit, both for biting into hard fruits and for keeping the wadges of tough fibrous fruit into the mouth during prolonged bouts of chewing.

Humans range in size from about chimp-size to much larger. This mean that humans have a higher demand for energy for both growth and maintenance of the larger size, which in turn would place more demands on the human diet (in terms of total energy). Chimp guts seem to be larger relative to body size suggesting that chimps eat a lower-quality food that requires more processing in the gut.

But why compare chimp and human indicators of diet when we can actually observe chimp and human diets? No good reason, actually, other than to prepare the groundwork for comparisons that cannot be made by direct observation (the diets of extinct hominids).

Living chimps like to eat fruit, and they eat what is known in the biz as “Terrestrial Herbaceous Vegetation” (hereafter: THV) as a fall back food when fruit is not available. Forest salad is better than starving. Chimps also eat some meat. But what does the typical human diet consist of?

This is a problem, because as we look at different human populations, we see a huge amount of variation. One way to make sense of the diversity of human diets is to start by only considering the diets of hunter-gatherers. But among hunter-gatherers, there is still a huge range of diets. Some human forager groups eat almost all meat, others eat very little meat, for example. OK, so we can simplify this even more by focusing on human hunter-gatherers who live in tropical and subtropical regions, since people have moved into temperate and colder regions only several thousand (or tens of thousand) of years ago. But we still encounter a large amount of variation. With respect to meat eating, we’ve only eliminated the most extreme cases such as the Inuit.

One thing that obviously sets human diets apart from all other mammals is that a very large percentage of the food that humans eat is cooked. This is important. Consider these two probable facts:

1)An important percentage of the food that all human groups consume is cooked and can only be eaten if cooked; and
2)Many environments in which human foragers live or have lived provide food that is insufficient for human sustenance unless it is cooked.

In other words, not only do we eat a lot of cooked food, but without that cooked food there are probably many regions of the world where our species would simply not survive.

Putting it yet another way: The ability to cook food transforms most environments on this planet into one habitable by humans. THIS is a link to a paper that suggests that the origin of cooking (which involved the controlled use of fire) is indicated in the fossil record by a strong biological signal. This signal consists of a huge increase in body size accompanied by an impressive reduction in tooth size. These two changes are at odds with each other: How do you manage a huge increase in energy requirements for growth and maintenance at the same time as a decrease in the basic apparatus for obtaining energy? There are other physical changes as well, and broad implications including changes in mating system, suggested in our paper. Enjoy!

Above, I talked about drawing a straight line from a chimp like ancestor to modern humans, but many of you knew that I was just leading you on. You know this because one of the major findings of the last 35 years of human origins research is that our lineage has undergone change not in a single direction (leading to “us”) but rather in various different directions at different times. The key characteristic of the rise and diversification of the australopiths and their close relatives was probably NOT becoming bipedal. Oh sure, that was important and everybody goes gaga over that interesting fact. But the most important adaptive innovation was probably megadonty and related adaptations. This involved the surfaces of the teeth becoming larger, the enamel thicker, and teeth that are normally not used in chewing being recruited to varying degrees to doing the job of the molars (along with the giant molars themselves, of course).

Concurrent with this was NO change in body size (at least none that follows any sensible pattern); a probable increase in sexual dimorphism indicating a mating system shift from something like a living chimp (multi-male multi-female) to something more like a gorilla (single reproductive male and a harem of females), as well as some other details like a larger mouth interior signaled by a high arching palate.

Again, I’m going to send you to a paper, which you can download HERE. In this paper, we argue that the primary novel adaptation of these australopiths was the use of plant underground storage organs (roots and such) as the principle fall back food. In other words, a chimpanzee like ancestor, forcing on fruit as it’s primary food and THV as it’s fall back food probably continues eating fruit (and some meat, we suppose) but changes it’s fall back food from leaves to roots.

There are many important implications of this, some speculation some not. For instance, there are more roots in drier environments. As you measure root availability from the rain forest, wooded savanna, open savanna, and arid areas, you get more and more as you move along a transect from wetter to drier habitats. A chimpanzee like animal would be confined to the rain forest not only because its primary food (fruit) is more abundant there, but perhaps more so because it’s all-important fall back food … the food it eats to avoid starving in a bad season or year … is confined to the rain forest. Chimps would not be able to eat most of the non-rain forest plant leaves. But if you swap roots for THV, it is now actually preferable to leave the rain forest to seek this fall back food.

The eating of USOs as a fall back food essentially served as a kind of conveyor belt moving these hominids from the rain forest into other, more open biomes. We suspect it shaped social structure and behavioral ecology of the australopiths as well. In some way, it could be said that these early hominids were more different from either chimps and humans than humans and chimps are to each other (… hey, I said SOME ways…. ).