Bigger Brains in Human Ancestors

Researchers discover a 1.2 million-year-old female pelvis that holds the key to brain evolution

By Jaya Jiwatram Posted 11.17.2008 at 1:13 pm 4 Comments

H. Erectus pelvis, reconstructed It's wider than those previously known and suggests to researchers that human ancestors had larger brains than commonly believed. Scott W. Simpson, Western Reserve University

Researchers reveal that a 1.2 million-year-old female pelvis they found in Ethiopia in 2001 suggests our predecessors were larger-brained than previously thought

The story of evolution got bigger last week when researchers revealed in the journal Science that they had discovered a wide-hipped pelvis, suggesting our ancestors were larger-brained than formerly thought. The first of its kind, the 1.2 million-year-old, near-complete female pelvis is from the now-extinct Homo erectus species, believed to be our first human-like relative to leave Africa.

Previously, researchers postulated H. erectus females had narrower hips, consequently making it harder for them to give birth to larger-brained babies. Scientists believed this explained how humans evolved to have long childhoods since smaller-brain children would be more dependent on their mother. But this assumption was mainly based on the small pelvis dimensions of "Turkana Boy," a 1.5 million-year-old, tall young male of the same species found in Kenya in 1984. Believed to be more than 6 feet tall, Turkana Boy led scientists to theorize that early humans were taller and narrower-hipped to help them maintain a constant body temperature while running long distances in hot climates.

The latest discovery, however, of a female pelvis found near Gona in northern Ethiopia challenges earlier notions of our ancestors. The researchers found that the birth canal of the pelvis, which belonged to a 4 feet 5 inches tall H. erectus woman in her 20s, was more than 30 percent larger than earlier estimates. The woman's hips were even proportionally wider than those of modern humans, suggesting that the larger brain size of a H. erectus child made him less dependent on his mother than a modern day baby. This adaptation would have been useful for survival in the African savannah where the H. erectus lived. While the discovery has raised a lot questions, it could help give scientists greater insight into when humans developed larger birth canals in our evolutionary history.

[Via Discover]

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4 Comments

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Gringo13

11/17/08 at 3:20 pm

Why is it so important that we know when we evolved and how? I think its just about competition who will fill more blanks i our history.

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ford2go

11/18/08 at 1:48 am

So another discovery gets forced into the evolutionary model. Damn the anomolies, full speed ahead.

I'm not suggesting Intelligent Design ( don't want to be branded a heretic!), but there may still be a case for different theories.

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demcnn

11/20/08 at 8:33 pm

"So another discovery gets forced into the evolutionary model. Damn the anomolies, full speed ahead.

I'm not suggesting Intelligent Design ( don't want to be branded a heretic!), but there may still be a case for different theories."

ford2go, I am disheartened by a few of the statements you have made. I think first off I am bothered by your apparent lack of understanding for how the 'evolutionary model' works. While this is a common problem in the USA today, the lack of understanding for the position of which one criticizes (especially evolutionary biology), it is no excuse to assume a new discovery causes a problem for the current model. In fact, the anomaly caused by finding this fossil, a 1.2 million year old fossil (it should be recognized just how old this fossil is after all), is actually beneficial to the evolutionary model.
As it states in the article itself, "Previously, researchers postulated H. erectus females had narrower hips, consequently making it harder for them to give birth to larger-brained babies." There was originally a hypothesis from which scientists postulated possibilities to help explain another unknown period in human evolution; "Scientists believed this explained how humans evolved to have long childhoods since smaller-brain children would be more dependent on their mother." As you read on in the article you will see that the scientists based this hypothesis and subsequent possibility on another fossil, "Turkana Boy led scientists to theorize that early humans were taller and narrower-hipped to help them maintain a constant body temperature while running long distances in hot climates."
This theory came about due to this particular individual fossil. Assuming for moment that our ancestors were remotely similar to us in their general populations ability to differ at least minimally in size and build, one could argue that the particular fossil they found may have in fact not represented the population as a whole, but rather just some of the general features of the species. Also you may notice the difference in today's male and female bone structures. The scientists were basing their hypothesis off of a [MALE] fossil, not off of the newly discovered [FEMALE] fossil. Using the new fossil they can now postulate, as the article states, "The woman's hips were even proportionally wider than those of modern humans, suggesting that the larger brain size of a H. erectus child made him less dependent on his mother than a modern day baby." And as the article goes on to state, "This adaptation would have been useful for survival in the African savannah where the H. erectus lived."
Though the discovery may have raised more questions (why is that a bad thing in the first place?) it has helped scientists come up with a more accurate model for human ancestry, and when particular physical and genetic traits began or dropped off. We now have a fossil where we once did not have one, and this fossil helps to explain why and when the modern day humans difference in birth canal size came about.

The second thing that bothers me about your statement is that you would not want to take up a position for fear of being accused of something you are not. If you have evidence for your position, then you should take up the position even if you are going to be "branded a heretic!" I am not sure who is going to be branding you as a heretic from the scientific community, but if you have strong enough evidence for your position you should not be afraid to stand with it. However, if your position does not hold true or at least hold up with the other theories of the time, then you should possibly accept that it is either outdated or just flat out incorrect. There may still be a case for different theories, there always is in science, that is the most beautiful characteristic of science (if you want an example read about static universe theories and big bang theory). But to think that evolution is on its way out is just naive at best, moronic at worst. It is a fairly young model, especially when you get into genetics, that is going to continually change for as long as we are studying biology. To assume that in just over 100 years we can know everything that has happened throughout life over the course of a few billion years is just asinine. There is much more to the rigors of science than just saying, "I do not know what happened here, so I will just say [blank] happened. The end!"

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DVineDZine

01/07/09 at 3:08 pm

I enjoy reading the articles of scientists but:

I personally find the idea of evolution to be comical and ludicrous. The fact that human beings and all life forms, for that matter, procreate simply by an exchange of fluids is the most remarkable miracle of all.

The fact that humans create baby humans, dogs create puppies and the list goes on and on and on and on! The life cycle is so perfect. It is by divine design and nothing else even remotely explains our existance on this planet along with so many hundreds of millions of other life forms that reproduce so perfectly. That's just the human beings not including the reptiles, fowls, insects, micro organisms which number in the hundreds of millions. In other words, you can't count the life forms that have been, are or will be on this planet.

It takes greater faith to believe in evolution then it will ever take to believe in a designer. The very idea that evolution is responsible for the beauty of life. Evolution suggests time, chance and chaos are responsible for our existance but if that were true, nothing that is here today would be the same tomorrow because it would have evolved and the only thing I see is life begats life.

We live a while and we die with most of us choosing to leave an extension of our existance behind in our children. It amazes me how people can believe in evolution and not God. I know people that can't read or write, can't talk, can't walk, can't see yet they can have a sexual experience with a member of the opposite sex and ultimately create a body with a brain (Most complex organ in the body), lungs that breathe, two eyes that can see, ears that can hear, mouths that speak, two arms two legs but yet they are considered less intelligent than our surgeons and doctors that attempt to repair these organs and limbs. Kudos to our doctors and surgeons but they are still just men & women! We are all different yet we're all typically the same and this doesn't happen by chance.

It's not where we came from that matters, it's where we're going that should be our focus. If a person enters a cemetary or burial ground and digs into a grave it is a crime and the person can go to jail or prison but because modern grave yards contain known human remains that do not fill evolutionary gaps for evolutionists, these sites are protected by law. If an evolutionist, in an attempt to disprove divine design, wants to dig an ancient grave it's called science. Grave robbers are grave robbers regardless of when the person was born or when they died.

True science will put facts together. Assuming something to be true is ignorance. To teach unproven assumptions as truth is a lie and it's ignorance gone to seed..

Considering the complexity and beauty of life and procreation, If you're going to assume something, assume that we're created in the image and likeness of God and rightfully the children of God. Not the children of apes or monkey's.

The wonder and glory of nature alone testifies of God and a designer. Problem is, if you reject God, it's an unwillingness to be accountable to a higher power and man in his fallen pride wants to be accountable to noone other than themselves.

Also, true science should always be open to the views and beliefs of others because simply put, If you don't know where we came from then you're not qualified to teach where we didn't come from. The spirit in a human yearns and calls out to know God! Every human has an unction in the spirit that knows there is a designer (God). It's the soul (mind) of man that argues God's existance.

From the heart, Search your heart! We're not mindless monkey's and your own heart will speak to you.