Exam review, Archaic Hominins Flashcards
what are some of the archaic hominins
H. erectus, H. antecessor, H. heidelbergensis and H. neanderthalensis
what was a result of H. erectus / ergaster Brain Development
Encephalization is the increase in brain size, relative to body size
The trouble with a focus on brain size and cranial capacity is that it measures only the dimensions of the brain, not neural activity or structural complexity.
The relatively thin cerebral cortex is where the majority of brain activity takes place. Humans have highly textured brains, allowing for more overall cortical surface
While bipedalism was the first major distinction between hominins and apes, long-term encephalization was the most dramatic and lasting.
It is important to note that due to the complex physical structure of the human – and, by extension, the hominin – brain, size is not the only factor in intelligence. For example, we can’t say for certain that H. erectus / ergaster was 50% more intelligent than Au. africanus just because the latter’s cranial capacity was 50% lower
what might have been the first to use language
H. erectus
Bivalve shells with geometric engravings were recovered where
in the 1890s from the H. erectus erectus site of Trinil on Java,
Volcanic sediment within the shell indicates it is how old
500,000 years old
who made the Bivalve shells with geometric engravings
H. erectus
There is evidence of a hominin (possibly H. erectus) presence in Europe between 1.2 mya and 800 kya at sites such as
Atapuerca, Spain and Boxgrove, England; however, non-sporadic occupation of Europe didn’t begin until around 500 kya.
what species are collectively known as archaic H. sapiens (archaic hominins)
Middle Pleistocene European and African hominins share many morphological similarities with anatomically modern humans
what is the term (archaic hominins) a blanket term referring to
those species likely bridging the gap between H. erectus and anatomically modern humans. Many of the physical traits of H. erectus/ergaster appear in the archaic hominins.
An ancestor of the archaic hominins in Europe (and a candidate for a European variant of H. erectus) was a species known as what
Homo antecessor
when did H. antecessor live
1.2 mya to 780 kya
where was H. antecessor found
Fossils believed to belong to H. antecessor are limited to Atapuerca, Spain. It’s a relatively small sample on which to base observations of an entire potential species
Ancillary (non-fossil) evidence has been found in England and France
H. antecessor had an average cranial capacity of around what
1000 cc
Know that the first solid evidence for hunting (as opposed to scavenging) is found among what species and where
H. heidelbergensis fossils and artifacts in Germany
who made the Happisburgh Footprints
H. antecessor
where is H. heidelbergensis found
in the German city of Heidelberg; hence, the species name.
The vast majority of fossils have been found in Europe (Germany, Greece, Italy, Britain)
what is Bergmann’s rule
states that that among polytypic species, body size is larger in colder climates to conserve body temperature
Think of it like this: body surface area decreases relative to body volume in colder climates (less body surface allows for less heat dissipation)
H. heidelbergensis Evidence for Hunting
In 1994, a total of 8 separate, six-foot-long, well- crafted wooden spears were found at Shöeningen, Germany. Also found within these contexts were lithic flakes and more than 10,000 large-‐mammal bone fragments (including horse!). All material dates to around 400 kya.
Widely-associated with H. heidelbergensis, the Shöeningen material is the earliest-known evidence of technology designed explicitly for hunting large game
when did H. floresiensis live
100 - 50 kya
where was H. floresiensis found
cave site on the island of Flores, Indonesia
what is unique about H. floresiensis
they were small
what made H. floresiensis ssall
Over time, a phenomenon known as insular (or “island”) dwarfism likely reduced their size dramatically.
Related to two selective pressures:
1. Islands (with fewer resources) favour smaller individuals who need less food to survive
2. Fewer predators on islands means there is no disadvantage to having smaller, less defendable body size
what are the H. floresiensis Skeletal Morphology
LB1 Cranial Morphology Only one relatively complete cranium (LB1) was recovered. Very low cranial capacity (380 cc). High vault elevation above orbits. Gracile supraortibal tori. Low degree of postorbital constriction. Low degree of facial prognathism. Generalized dentition, reminiscent of that of modern humans
what was the debate over phylogeny
There was considerable initial debate over whether the type cranium (LB1) represented a microcephalic adult modern human, or one without a functioning thyroid (cretinism).
This was shown not to be the case; however, this is precisely the kind of question that should be asked of new fossil finds!
Natural selection alone—in the form of insular dwarfism—is widely considered to be the best explanation for the small stature of H. floresiensis
when did H. naledi live
335 – 236 kya
where was H. naledi found
Rising Star Cave
H. naledi Skeletal Morphology
Outline shape and profile resembles Homo erectus / ergaster
Crucially, cranial capacity is between 465 (females) and 560 (males
Generalized dentition and comparatively small teeth
The foot is fairly modern in shape, with a pronounced arch
was there a H. naledi Burial Culture
“There is no evidence of material culture, like tools, or any evidence any kind of symbolic ritual that we almost always associated with burial. … These bodies seem to have simply been dropped down a hole and disposed of.”
what is the controversy over the chronology over H. naledi
Many researchers claimed that based on statistical analyses of morphology alone, H. naledi must have lived sometime around 2 mya (+- 500 kya)
Intial classifications grouped H. naledi closest to H. habilis and H. erectus based on anatomical similarities and assumed chronology
WRONG: Uranium-Thorium (radiometric technique used to date cave deposits) and Electron Spin Resonance (ESR) of teeth enamel yielded dates between 335 – 236 kya
what are the Problems / Questions raised by H. naledi
Cladistic classification (homologous traits) can be misleading! H. naledi may serve an example of a species with more ‘primitive’ traits that survived longer than other hominins Did H. naledi evolve in isolation? Unlikely, since we know S. Africa is FULL of other hominins, notably Anatomically Modern Humans (AMHs) at the same time. What was its relationship to them? Along with H. floresiensis, natural selection can no longer be assumed to be universally driving the evolution of larger brains in hominins during the last million years. What does this mean for our understanding of modern human complex thought?
