Faithful Ancestors

A weird kind of creature strode across the eastern African landscape from around 4 million to 3 million years ago. Known today by the scientific label Australopithecus afarensis, these ancient ancestors of people may have taken the battle of the sexes in a strange direction, for primates at any rate. True, no one can re-create with certainty the court and spark that led to sexual unions between early hominids. Nothing short of a time machine full of scientifically trained paparazzi could manage that trick.

All is not lost, though. Scientists are looking to fossil remains of A. afarensis to provide, as a prehistoric tabloid would, a revealing exposé of the hominid's intimate tendencies. A statistical analysis 2 years ago indicated that A. afarensis males exhibited only a moderate size advantage over females, rather than the larger difference seen in gorillas. According to Owen Lovejoy and Philip L. Reno, both of Kent (Ohio) State University, who directed that study, the size similarity implies that A. afarensis adults of both sexes favored long-term relationships, which arose as a matter of survival, not morality. Sleeping around just didn't cut it during hominids' start-up era.

That view has generated controversy, which comes as no surprise to the Kent State scientists. They themselves had unabashedly dismissed other researchers' earlier work that depicted A. afarensis males as the considerably larger sex, with the fiercest male fighters monopolizing the mating game.

However, some recent work provides evidence for A. afarensis sex differences that were considerably greater than those in modern people and that approach those in gorillas, according to J. Michael Plavcan of the University of Arkansas in Fayetteville and his colleagues. They report their analysis in the March Journal of Human Evolution. Large sex differences would indicate a mating style similar to that of modern gorillas.

Lovejoy and Reno, however, stand by their earlier conclusions. "It's entirely possible that much of our sexual physiology and anatomy had already evolved in australopithecines," Lovejoy says. "That set the stage for massive brain growth in our later fossil ancestors."

Anthropologists discovered evidence of A. afarensis, including the partial skeleton dubbed Lucy, in eastern Africa more than 30 years ago. The bones seemed to fall into two size categories. At that time, researchers butted heads over whether these bones represented two species of human ancestors that lived at the same time or one species that included males with big, bulky bodies relative to those of females.

After noting similar shapes of the larger and smaller remains, proponents of the one-species view won out. Using measurements of people's bones in relation to body weight as a reference, investigators then estimated that A. afarensis males weighed an average of 98 pounds, while their female counterparts tipped the scales at only 65 pounds. That's a much greater sex disparity in weight than is found in people today but approaches that measured among gorillas and orangutans.

Many researchers concluded that in Lucy's species, as among gorillas, the toughest males dominated the mating scene. Gorilla males tend to fight among themselves, baring daggerlike canine teeth. Winners do the lion's share of mating with available females, whom the dominant males guard from skulking suitors.

Demonstrating another lifestyle, chimps exhibit virtually no size differences between sexes, but males retain large, fanglike canines, Lovejoy notes. A female typically mates numerous times with several partners during periods of sexual receptivity, which she advertises via temporarily swollen breasts and hindquarters.

According to Lovejoy, though, behaviors of gorillas or chimps can't serve as a model for Lucy and her comrades. In 1981, he proposed that they were descendants of a new kind of primate built for what he calls social monogamy. A. afarensis males blended an upright stance and unusually small, nonthreatening canine teeth. And the female anatomy masked signs of ovulation through features such as permanently enlarged breasts, he says.

Given this species' million-year run of success, Lovejoy theorizes, its males probably obtained food consistently by forming working alliances, mainly among close relatives. Each successful provider thus upped his chances of being accepted as a female's sole mate, the best way to ensure that he would become a dad. From the female perspective, a steady mate would be a good bet not only to bring home food but also to assist in child care.

However, modest size differences between the sexes typically characterize mammals with a penchant for soul mates, rather than the gorillalike pattern that had been proposed.

Ten years after Lovejoy set forth the idea of social monogamy among australopithecines, evidence continued to pile up supporting a substantial size difference between males and females. In 1991, Henry M. McHenry of the University of California, Davis published estimates of large weight disparities.

Lovejoy countered that those calculations used as a reference point the sex differences observed in modern people, which he says probably don't correspond to those of 3-million-year-old hominids. He also pointed out that McHenry's analyses rested on a small number of fossils that covered a time span of at least 500,000 years and were unearthed at sites separated by nearly 500 miles. The specimens could have come from populations showing a variety of unique male-female anatomical contrasts.

Finally, cursed with a scarcity of pelvic remains that could clearly distinguish wider-hipped females from slimmer-hipped males, McHenry simply assumed that big bones came from males and small bones came from females, Lovejoy says.

In 2003, Lovejoy and his coworkers employed a novel statistical method to simulate skeletal-size differences between ancient sexes without trying to gauge their weights. The enterprise hinged on using measurements of Lucy's partial skeleton to estimate sizes of crucial but missing bones for a set of A. afarensis individuals known as the First Family. These fossils, which represent as many as 22 or as few as 5 individuals, were unearthed near the spot where Lucy was found and, like her, date to 3.2 million years ago.

The researchers first measured the width of Lucy's well-preserved femur head, the ball of the upper-leg bone that fits into the hip joint. They then determined the size of various other parts of Lucy's arm and leg bones relative to femur-head width. Lovejoy focused on femur-head size because it's considered a reliable indicator of overall body size.

Next, the scientists measured the First Family arm and leg fossils that corresponded to those for Lucy. Armed with Lucy's skeletal dimensions, the team calculated femur-head sizes. They tagged individuals with big femur heads as male and those with small femur heads as female. In further studies the researchers found that femur-head sizes accurately predict sex and overall body size in people, chimps, and gorillas.

Whether the First Family included two dozen or only a half-dozen members, males exhibited a moderate size advantage over females, close to that observed in people, Lovejoy's team found.

Moderate, humanlike size differences between A. afarensis males and females accompanied both an evolutionary shriveling of males' canine teeth and a shift of sexual physiology away from chimplike ancestors and toward humans, Lovejoy asserts. For instance, he suspects that that's when ovulation became concealed and males evolved physical accommodations to mate regularly rather than for short, intense periods during ovulation. The new-style males produce modest amounts of sperm continuously rather than larger amounts timed to ovulation, as do gorillas.

Australopithecines, as highly mobile creatures locked into a socially complex mating game, lit a fuse of brain expansion that exploded in ensuing Homo species, Lovejoy proposes. Ironically, large brains unleashed cultural evolution, resulting in a plethora of human sexual and mating practices that go far beyond anything Lucy could have imagined, he says.

The Kent State scientists' portrayal of A. afarensis sexes has received some positive reviews. Robert G. Tague, an anthropologist at Louisiana State University in Baton Rouge calls Lovejoy's method of estimating skeletal-size differences "a promising one" and suspects that Lucy's kind indeed preferred social monogamy.

Lovejoy's findings indicate that early hominids "may have been more humanlike [than apelike] in their basic social behavior," comments Clark S. Larsen, an anthropologist at Ohio State University in Columbus.

But other researchers contend that the accumulated evidence supports striking size differences between A. afarensis sexes. These scientists reject Lovejoy's unconventional approach. To begin with, says Plavcan, the First Family consists mainly of large-bodied males and thus fosters an underestimate of size differences.

Plavcan and his colleagues determined the relationship between various skeletal measures and body mass for 658 people from eight populations in different parts of the world. With those correlations, the team made new calculations of femur-head size and body mass for seven A. afarensis specimens not in the First Family and assigned sex on the basis of size.

This work reveals sex differences considerably greater than those in people and approaching those in gorillas, according to Plavcan's team.

Particularly fierce males in Lucy's species probably monopolized mating, although how they did so without sharp canines remains unclear, Plavcan says.

Mating-minded A. afarensis males, McHenry theorizes, literally took up arms. An upright posture freed their hands for punching, throwing rocks, and other mayhem. The best fighters thus defended their exclusive sexual access to adult females.

It's risky to judge a hominid's body weight by the size of its bones because nutrition and other factors influence the amount of muscle and fat, says Christopher Ruff of Johns Hopkins University School of Medicine in Baltimore. He discounts Lovejoy's conclusions, arguing that an individual's skeletal size often bears little relationship to body weight.

UC-Davis' McHenry is sticking with his earlier calculation that A. afarensis males were about 50 percent heavier than females. Humanlike size proportions for the sexes evolved much later, around 1.7 million years ago in Homo erectus, McHenry argues. Men today are about 15 percent heavier than women.

Other scientists express a mix of chagrin and disdain at the amount of energy that researchers have expended on trying to separate fossil boys from girls. Investigators need to drop their obsession with the sex of fossils and examine how individual differences in skeletal anatomy arise, contends Maciej Henneberg of the University of Adelaide in Australia. For body weight and many skull measurements, including braincase size and facial width, individuals within each sex usually differ far more from each other than average members of opposite sexes do, he argues.

Erik Trinkaus of Washington University in St. Louis also derides efforts to identify the sex of ancient bones. Sex assessments always begin with the unjustified assumption that bigger bones must belong to males and smaller ones to females, he says. And the numbers of individual specimens of A. afarensis and other ancient hominid species are too few to generate reliable estimates of male and female size ranges, in his opinion.

Louisiana State's Tague doesn't go that far, but he notes that even the pelvis, the body part regarded as the gold standard for telling apart primate sexes, is surprisingly tough to read. His work shows no consistent pattern of the pelvis being larger in females than in males.

The shape of Lucy's partially preserved pelvis leaves her sexual identity unclear, Tague notes. Her diminutive size led Tague and Lovejoy in a 1998 paper to peg Lucy as female.

Reports on new fossil finds of A. afarensis and even older hominid species are expected soon. Lovejoy plans to factor skeletal data from these discoveries into a larger examination of ancient sex differences.

From Lucy's era to our time, the battle of the sexes appears destined to rage on.

"As I Thessalonians 5:11 states:" "Prove all things; hold fast that which is good." "The Bible itself demands and commends a logical test of its claims.(Acts 17:11)

Creationists have a much more recent history than the Ancient Israelies. In the 1800's when Creationism was the leading theory/explaination of the day scientists actually tried impressively to fit new physical findings to the books of Moses. As the Ark got bigger and bigger to hold all the new species it sunk. But those scientists unlike the 'got-ya' Creationists of today actually had a scientific theory of origins to defend.

Creationism is so anti-conservative. It involves a blind faith that is threatened by science/rational thought. It attacks what it sees as the alternative(science) yet claims that any discussion of itself is invalid because it is anti-God(CK post 92). The progressive/socialists/communists dream of Man induced Heaven on Earth/social justice/world peace is also untouchable. Like Creationism it has had its day, a complete and utter failure. The believers are out to destroy the alternative (liberal-democratic-capitalism) and any discussion of the failed Dream of Heaven on Earth(like Creationism) results in an attack as a racist, sexist, homophobe, tool of the corporations (or called atheist by Creationists.) Both are ‘any means justifies the end’/ 'can't be debated' beliefs and are scary.

"The rain lasted 40 days. The longer period of time was for the lowering of the water level" (ref your post 92)

My reply :
Genesis 7:4,+12, +17 : "The flood was on the earth 40 days and 40 nights "
but Genesis 8:5 says :"and the waters continued receding until the 10th month , on the first of the 10th month the 'tops of the mountains' appeared."

This is literal reading. The Flood lasted both 40 days +40 nights 'and' 10 months(perhaps Noah took two Cruises, not one). Which do we teach in science? J or P? And why are you intentionally misinterpreting your source of 'all' knowledge ??

And was Moses on these cruises? He supposedly wrote all these versions of the same story.

More importantly, if your using the Scientific method, one is open to discussing that inaccuracy and willing to entertain other, more accurate, models.

Do you know how much theological and popular (let alone scientific) credibility the flat earth model has enjoyed throughout history? Without question if science is open to discussion it will not altogether discount intelligent design as an agent in creating and sustaining the universe as we know it. The model actually fits well inasmuch as aggregations of matter with function and purpose have sprung up down to the molecule, DNA being a case in point.

I will be the first to admit certain proponents of theology are capable of erring both in their understanding of biblical texts and ther lack of appreciation for the physical sciences. I would only think it reasonable for science to speak with certainty concerning matter it knows, and with some qualification in matters of reasonable conjecture.

"Genesis 7:17 is speaking of the 40 days that the flood was on the earth AND the waters increased."

My Reply :
It does not say that. You are adding that as to make it seem like one story. Gen 7:24 : "And the waters grew strong on the earth 150 days". More :

Gen 8:7 He sends out a Raven to find land, But Gen 8:8+10 he sends out a dove.

In J he brings a pair of each type of animals but in P he is concerned with clean and unclean animals because the writers of P were the priests ,gate keepers of sacrifice of animals at the temple. Check for yourself::
J:Gen 6:19 And of every living thing, of all flesh, you shall bring two of every kind into the ark, to keep them alive with you; they shall be male and female
P: Gen 7:2 :Take with you seven pairs of all clean animals, the male and its mate; and a pair of the animals that are not clean, the male and its mate;
Gen7:3 and seven pairs of the birds of the air also, male and female, to keep their kind alive on the face of all the earth.

Lets see creation where in P man is created last, but in J he is created first.

P first: Gen 1:11 In the beginning when God created the heavens and the earth,
Gen 1:24 And God said, "Let the earth bring forth living creatures of every kind: cattle and creeping things and wild animals of the earth of every kind." And it was so.
Gen 1:25 God made the wild animals of the earth of every kind, and the cattle of every kind, and everything that creeps upon the ground of every kind. And God saw that it was good.
Gen 1:26 Then God said, "Let us make humankind in our image, according to our likeness; and let them have dominion over the fish of the sea, and over the birds of the air, and over the cattle, and over all the wild animals of the earth, and over every creeping thing that creeps upon the earth."
Gen 1:27 So God created humankind in his image, in the image of God he created them; male and female he created them.

But in the J version the order is reversed. J: Gen 2:4 These are the generations of the heavens and the earth when they were created. In the day that the Lord God made the earth and the heavens,
Gen 2:5 when no plant of the field was yet in the earth and no herb of the field had yet sprung up—for the Lord God had not caused it to rain upon the earth, and there was no one to till the ground;
Gen 2:6 but a stream would rise from the earth, and water the whole face of the ground—
7 then the Lord God formed man from the dust of the ground, and breathed into his nostrils the breath of life; and the man became a living being.
8 And the Lord God planted a garden in Eden, in the east; and there he put the man whom he had formed. 18 Then the Lord God said, "It is not good that the man should be alone; I will make him a helper as his partner."
19 So out of the ground the Lord God formed every animal of the field and every bird of the air, and brought them to the man to see what he would call them; and whatever the man called every living creature, that was its name.
20 The man gave names to all cattle, and to the birds of the air, and to every animal of the field; but for the man there was not found a helper as his partner.

"Biblical faith is not blind. That's why I've quoted Hebrews 11:1 which cites evidence as a component of faith. Why is creationism anti-rational?"

Because it goes against so many tested and verified scientific developments and the literal reading of the story presents objects and events that are unlikely or impossible.

"Everything had a begining. Nobody was around for that begining. Why is it itrrational to think that God created all things? What explanation is more logical?"

That the beginning can be determined through investigation and the compilation and examination of information, without resorting to the supernatural.

There is a rule in hermeneutics that says when you are dealing with an otherwise trustworthy work, the burden of proof is on the person alleging a contradiction to show that reconcilliation is impossible.

The later reference to seven clean beasts can be seen as merely as a further elaboration and addition to the basic instructions of one pair of every kind. This is the way it has always been understood and reconciled. I don't see why is it impossible to be reconciled now except it doesn't fit in with somebody's recent theory.

I think that the different numbers in the flood account are easily reconciled to be referring to different periods. 7:17 is the days of rain, the reference to 150 days is the increasing of the waters, the remainder of the time is the time it took for the waters to recede. That is the way it has been understood for thousands of years with no problem. But now we are to believe than mankind has suddenly increased in intelligence to see contradictions heretofore undetected. Again I say that the compilers of the E and J would be pretty dense not to smooth out such a clear contradiction as you allege. So do you think the reconciliation of these numbers that have been accepted as one story throughout history is impossible?

While I can see how someone whose heart is set on the documentary theory manufacturing a contradiction with the numbers, I don't see how anyone can have trouble with the section about the birds. Genesis 8:8 says that he ALSO sent forth a dove. There's nothing that says that if he sent forth a raven he couldn't send a dove later. Next time you look for contradictions, I wouldn't bother with that one. That bird won't fly.

As far Genesis 2:19 is concerned, I think you need to take note of a word missing in 2:19 that is present elsewhere. The word "THEN" is not in 2:19. If "then" was present we would have a contradiction, but the absence of this word eliminates the need to tie this verse to strict sequential order. We can now understand this to be referring to something that God had done previously and be in perfect harmony with Genesis 1.

That the beginning can be determined through investigation and the compilation and examination of information, without resorting to the supernatural.

The beginning is going to have to be supernatural. We don't see the creation of the universe every day. It seems only the most illogically hardcore of atheists would maintain that matter is eternal. If the creation of matter is supernatural work of God, the creation of life is a small thing. Could not the creator of all matter create life in seven days, especially if He revealed that mankind? He certainly could have used the Darwinist method had He chosen, but the natural law we read about is that life begets its own kind. Jesus Christ endorsed the Genesis account as fact in Matthew 19:4. A lot of people who profess belief in Christ try to keep a foot in both camps by belief in a "theistic evolution". But this is the same as rejecting Jesus as an ignorant charlatan.

"Genesis never said that the life that went into the ark was adults in age. And to be precise, Genesis never said that the ark carried each species, but each kind. The classification by species is but a few hundered years old."
So, the incredible variation in species we have now, including those that went recently extinct, is a result of 4500 years of evolution? WOW.

So no evolution ever, unless they need Noah's boatload of animals to evolve into all species we now see of bird and beast. But I guess that isn't "Macro" evolution because a deer still gave rise to all the different species of deer. WOW indeed! Other words escape me.

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