Joana Rodriguez

Anthropology 120G

Final Essay Fall ‘03

December 4^th 2003

Final Essay

Tracing our evolutionary roots is a tricky thing. There are at least two popular theories as to how and when we came about. Deciding which theory you believe, however, is possibly the easiest step.

There are two main theories as to how the evolutionary ladder occurred; the first theory is the Multiregional Hypothesis. In this theory followers believe that evolution is a slow and gradual thing (much like Darwin did) and that each sequence in time occurs in small steps, not leaps and bounds.

Multiregional Hypothesis Points

v Anagensis is the mode of speculation.

v Regional populations continued to interbreed at their borders leading to gene flow between them.

v No more than one intelligent bipedal could coexist.

v Homo has been one continuous lineage since H. habilis.

Now the multiregionalists tend to believe that modern Homo sapiens carry a mixture of H. sapiens and Neanderthal genes within them, not to mention they also tend to have fairly radical ideas such as the belief that a Neanderthal looks so much like a modern H. sapiens that one could dress him up in our modern clothes and stick him on a subway and no one would notice him or think twice about him. Now, just to point out some glaring flaws in this idea, notice they say “stick him on a crowded subway” and not “place him in a quiet library” or some other such place. Were they hopping that on a busy subway everyone would be in too much of a rush getting to their destinations to notice the man with no forehead, gargantuan build, humungous nose, and ape-like face? Methinks they underestimate the intelligence of people today.

An outline of the Multiregional Hypothesis:

H. habilis

↓

H. erectus

↓

H. sapiens ↔ Neanderthals

↓

H. sapiens ↔ sapiens

Regionalists really like to keep things simple and wish to have little to no sub species (as you can see) and have all of the findings line up in chronological order. Life is hardly ever that simple however. Another theory, which is the one I tend to agree with, is known as the Out of Africa theory.

The Out of Africa theory suggests that we had a figurative Adam and Eve group living in Africa that all Homo can be traced back to, a father figure or if you prefer a common ancestor. This theory suggests that we are the product of reproductive isolation (return of the bottle neck).

Out of Africa Theory Points:

v Cladogenesis is the mode of speciation.

v Speciation most likely occurred in small isolated populations following natural disastors (genetic bottle necks).

v Nothing prevents new and old species from living at the same time (being contemporaries)

v There were many different species of Homo, only some lead to us.

Much more believable, not to mention logical; under the Regionalist hypothesis no two kinds of Homo could coexist let alone two intelligent bipedals. As such would that have implied that Neanderthals were inferior in intelligence since they died out? Such a comment would be untrue when one considered their hunting methods, tool making, and burial practice (something that prior to Neanderthals was only hinted at as a possibility in the Homo lineage). These are not the actions of the incompetent and inept.

Out of Africa Assumptions:

H. habilis

↓

H. ergaster

↓ ↓

H. antecessor H. erectus

↓ ↓

H. rhodensis H. heidelbergensis

↓ ↓

H. sapiens H. neanderthalensis

What really set the Out of Africa theory into motion was a notion by Chris Stringer during the 1990s that the skulls that had been found in China (Yunxian & Jinniushan) that had previously baffled the scientific community as to their origins, as they really didn’t into the ranks of any of the known species and had instead been all clumped together as H. erectus, were really a new species now called H. heidelbergensis and stated the possibility that they had all originated in Africa approximately 600-800 thousand years ago in a single population that than dispersed into Europe; as such H. erectus never did make it to Europe. Stringer proposed that at least three waves out of Africa.

Homo ergaster → Homo erectus (Asia)

Homo heidelbergensis → Homo heidelbergensis (Europe & Asia)

Homo sapiens → Homo sapiens (worldwide)

New discoveries in Spain at the Gran Dolina site in Atapuerca and one other site known as Sima de los Huesos have forced some modifications to be made to the Out of Africa model that also make the Regionalist model all that more unbelievable. First we’ll discuss the findings at Sima de los Huesos.

Within this cave excavators discover 1600 bones that represent at least 36 individuals of ages, considering the fact that only a partial skeleton (if even that) is usually what is found of past predecessors you can imagine the joy of finding 36 specimens to study. Imagine the variation! All of the individuals found at Sima de los Huesos are attributed to the species Homo heidelbergensis. Now wait I know what you’re thinking; we’ve already discovered H. heidelbergensis so what could possibly be so wonderful about this discovery? That my friend is simple, the keyword here is variation. With all the different yet same specimens to examine anthropologists discovered something rather startling, homo heidelbergensis shares so many traits with Neanderthals that it is nearly impossible for heidelbergensis to be one of our ancestors. For example it has a humongous nasal opening (Neanderthal trademark), projective middle face, prominent double-arched browridge above the eyes, a higher more rounded skull, and lack of occipital bun.

So if heidelbergensis gave rise to neanderthalis who gave rise to us? This is where the discoveries at Gran Dolina come into play. A new species was found and named by Jose Bermudez de Castro; its name is Homo antecessor. H. antecessor was found to share many primitive traits with the modern Homo signifying that these traits originated from this species, in its juvenile form at least, while older more mature versions share features with Neanderthals. What exactly does this mean? Well here are some possibilities:

§ That Homo antecessor gave rise to both Homo heidelbergensis and to Homo sapiens. Its our common ancestor.

§ That Homo heidelbergensis gave rise to Homo neaderthalensis in Europe but never to Homo sapiens.

§ That Homo heidelbergensis is restricted to Europe and something in Africa possibly Homo rhodesiensis would have evolved from and as of yet undiscovered population an H. antecessor in Europe and have given rise to Homo sapiens.

These discoveries give way to a new interpretation of the migration, observe:

1^st Wave

H. habilis → H. erectus with African and Asian populations diverging

2^nd Wave

H. erectus in Africa → H. antecessor → H. heidelbergensis

3^rd Wave

H. heidelbergensis populations and Africa and Europe diverge European H. heidelbergensis → H. Neanderthals Africa H. heidelbergensis → H. sapiens

Now if we are indeed from a completely different branch of Homo than Neanderthals is it at all conceivable that at some point Homo sapiens and Neanderthals began interbreeding and that much of the Regionalist hypothesis is at least correct, we do have Neanderthal genes within us today? The answer is very simply, no. Rather recent studies of Neanderthal DNA taken from bone samplings indicate that the differences between the two species were too varied to allow for successful reproduction.

Mitochondrial DNA sequencing of two different Neanderthals concluded that we had been separate from Neanderthals for 600,000 – 800,000 years. Y-chromosome studies showed that a figurative “Adam” would have lived about 59,000 years ago and would have originated in Africa, dispersal of males to Asia would have occurred at about 44,000 years ago along the south coast of Asia then on across the sea to Australia. All modern homos, no mater what their race, can trace their ancestry back to a single population out of Africa, meaning race has very little to do with evolution.

Dispersal of modern Homo sapiens to the Americas and Australia had to have occurred around 12,000 years ago and most likely by boat. It is likely that they traveled by boat because Homo sapiens were the first hominid to begin to utilize fishing and traveling along waterways. Its believed that at some point they began to engineer rafts to aid them in their fishing and later utilized this technology to disperse throughout the world. There has also been evidence that they had begun to make rope as well as their new tool technology known as upper Paleolithic.

Now before this paper comes to a close let us briefly sum up what little known facts there are of the species about their lifestyles and tool technologies.

Asian Homo erectus:

Ø No sign of mortuary practice.

Ø Odowan-like tool kit

Ø Does not seem to have developed the use of fire

Homo ergaster:

Ø Used Oldowan type chopper flake tools

Ø Later developed the use of Acheulean tools

Homo antecessor:

Ø Post mortem scalping a sign of a possible mortuary practice.

Ø Odowan-type tool kit

European Homo heidelbergensis:

Ø Signs of mortuary practice.

Ø Acheulean tool kit

Ø Possible cannibalism; definite scalping

Homo Neandertahlensis:

Ø Definate mortuary practice.

Ø Mousterian tool kit (same as Upper Paleolithic)

Ø Use of domestic fire

Homo sapiens of Upper Paleolithic :

Ø Definite mortuary practice, burial with burial goods. (orcra)

Ø Development of Paleolithic tool kit. Blades and points made with obsidian.

Ø Use of domestic fire

Ø Bone carved to make art, animal figures, harpoons, fishhooks

Ø Development of fishing

Ø Possible religion

Ø Personal adornment – jewelry

Ø Cave art