The Genus <i>Homo</i>: All in the Family - Evolution News & Views

Evolution News and Views (ENV) provides original reporting and analysis about the debate over intelligent design and evolution, including breaking news about scientific research.

Evolution News and Views
Evolution NEWS
 

The Genus Homo: All in the Family


Human Origins and the Fossil Record: A Recap
Human Origins and the Fossil Record: What Does the Evidence Say?
The Fragmented Field of Paleoanthropology
The Fragmented Fossil Record of Early Hominins
Later Hominins: The Australopithecine Gap
A Big Bang Theory of Homo
This Article: The Genus Homo: All in the Family
How do Theistic Evolutionists Explain the Fossil Record and Human Origins?

Read the Book:
Science and Human Origins

Science and Human Origins.jpgIn contrast to the australopithecines, the major members of our genus Homo -- such as erectus and the Neanderthals (Homo neanderthalensis) -- are very similar to modern humans. They're so similar to us that some paleoanthropologists have classified erectus and neanderthalensis as members of our own species, Homo sapiens.116

Homo erectus appears in the fossil record a little over 2 mya. The name Homo erectus means "upright man," and unsurprisingly, below the neck they were extremely similar to us.117 Indeed, in contrast to the australopithecines and habilines, Homo erectus is the "earliest species to demonstrate the modern human semicircular canal morphology"118 previously noted as a feature indicative of the mode of locomotion. Another study found that total energy expenditure (TEE), a complex character related to body size, diet quality, and food-gathering activity, "increased substantially in Homo erectus relative to the earlier australopithecines," beginning to approach the very high TEE value of modern humans.119 As one paper in a 2007 Oxford University Press volume notes, "despite having smaller teeth and jaws, H. erectus was a much bigger animal than the australopithecines, being humanlike in its stature, body mass, and body proportions."120 While the average brain-size of Homo erectus is less than modern humans, erectus cranial capacities are well within the range of normal human variation.

Cranial Capacities of Extant and Extinct Hominids121

TaxonCranial CapacitiesTaxon Resembles
Gorilla (Gorilla gorilla)340-752 ccModern Apes
Chimpanzee (Pan troglodytes)275-500 cc
Australopithecus370-515 cc (Avg. 457 cc)
Homo habilisAvg. 552 cc
Homo erectus850-1250 cc (Avg. 1016 cc)Modern Humans
Neanderthals1100-1700 cc (Avg. 1450 cc)
Homo sapiens800-2200 cc (Avg. 1345 cc)


Donald Johanson suggests that were erectus alive today, it could mate successfully with modern humans to produce fertile offspring.122 In other words, were it not for our separation by time, we might be considered biologically as interbreeding members of the same species.123

Though Neanderthals have been stereotyped as bungling, primitive precursors to modern humans, in reality they were so similar to us that if a Neanderthal walked past you on the street, you probably wouldn't notice many differences. Wood and Collard make this same point in drier, more technical language: "The numerous associated skeletons of H. neanderthalensis indicate that their body shape was within the range of variation seen in modern humans."124

Washington University paleoanthropologist Erik Trinkaus likewise argues: "They may have had heavier brows or broader noses or stockier builds, but behaviorally, socially and reproductively they were all just people."125 In a 2007 Washington Post interview, Trinkaus dispelled the myth that Neanderthals were intellectually inferior:

Although Neanderthals live in the public imagination as hulking and slow-witted "Alley Oops," Trinkaus and others say there is no reason to believe they were any less intelligent than the newly arrived 'modern humans.' Neanderthals were stockier and had larger brows, sharper teeth and more jutting jaws, but their brain capacity appears to have been no different than that of the newcomers.126
But it isn't just the "public imagination" which has wrongly cast Neanderthals as unintelligent brutes. A 2003 article in Smithsonian magazine traces these myths back to prior European anthropologists, who, inspired by Darwin, wrongly promoted the "subhuman" view:
"In the minds of the European anthropologists who first studied them, Neanderthals were the embodiment of primitive humans, subhumans if you will," says Fred H. Smith, a physical anthropologist at Loyola University in Chicago who has been studying Neanderthal DNA. "They were believed to be scavengers who made primitive tools and were incapable of language or symbolic thought." Now, he says, researchers believe that Neanderthals "were highly intelligent, able to adapt to a wide variety of ecological zones, and capable of developing highly functional tools to help them do so. They were quite accomplished."127
University of Bordeaux archaeologist Francesco d'Errico affirms these comments, stating, "Neanderthals were using technology as advanced as that of contemporary anatomically modern humans and were using symbolism in much the same way."128

Hard evidence backs up these claims. Anthropologist Stephen Molnar explains that "the estimated mean size of [Neanderthal] cranial capacity (1,450 cc) is actually higher than the mean for modern humans (1,345 cc)."129 One paper in Nature suggested, "the morphological basis for human speech capability appears to have been fully developed" in Neanderthals.130 Indeed, Neanderthal remains have been found associated with signs of culture including art, burial of their dead, and technology including the usage of complex tools. 131 At least one artifact shows Neanderthals made musical instruments like the flute.132 While this example might be dated and uncertain, there is even a report in Nature from 1908 that reports the discovery of a Neanderthal type skeleton wearing chain mail armor.133 Whether that report is right or wrong, it is clear Neanderthals were not intellectually dissimilar from their "human" contemporaries. As experimental archaeologist Metin Eren said, when it came to making tools, "in many ways, Neanderthals were just as smart or just as good as us."134 Likewise, Trinkaus says that when comparing ancient Europeans and Neanderthals: "Both groups would seem to us dirty and smelly but, cleaned up, we would understand both to be human. There's good reason to think that they did as well."135

One of these good reasons is the presence of "morphological mosaics -- skeletons showing a mix of modern human and Neanderthal traits which indicate "that Neanderthals and modern humans are members of the same species who interbred freely."136 In 2010 scientists reported finding Neanderthal DNA markers in living humans: "A genetic analysis of nearly 2,000 people from around the world indicates that such extinct species interbred with the ancestors of modern humans twice, leaving their genes within the DNA of people today."137 In the words of Jeffrey Long, a genetic anthropologist at the University of New Mexico, "Neanderthals didn't completely disappear" because "[t]here is a little bit of Neanderthal leftover in almost all humans."138 Unsurprisingly, these observations have led to proposals that Neanderthals were a sub-race of our own species.139

We saw earlier that Leslie Aiello said "Australopithecines are like apes, and the Homo group are like humans." 140 This is consistent with what we see in the major groups of Homo like H. erectus and Neanderthals. According to Siegrid Hartwig-Scherer, the differences between these humanlike members of the genus Homo can be explained as microevolutionary effects of "size variation, climatic stress, genetic drift and differential expression of [common] genes."141 These small differences do not supply evidence of the evolution of humans from earlier ape-like creatures.

Conclusion

While virtually the entire hominin fossil record is marked by incomplete and fragmented fossils, about 3-4 mya we see ape-like australopithecines appearing suddenly. When the genus Homo appears around 2 mya, it also does so in an abrupt fashion, without clear evidence of a transition from previous ape-like hominins. Subsequent members of the genus Homo appear very similar to modern humans, and their differences amount to small-scale microevolutionary changes.

At the beginning of this series I quoted SMU anthropologist Ronald Wetherington telling the Texas State Board of Education that the fossil record shows an unbroken sequence documenting our gradual Darwinian evolution from ape-like species. Were we to revise Wetherington's testimony in light of the actual evidence discussed in the technical literature, we might say that the hominin fossil record is anything but unbroken. There are many gaps and virtually no plausible transitional fossils.

Thus, public claims of evolutionists to the contrary, the appearance of humans in the fossil record appears to have been anything but a gradual Darwinian evolutionary process. The Darwinian belief that humans evolved from apelike species requires inferences that go beyond the evidence and is not supported by the fossil record.

[Editor's Note: This is an excerpt from Chapter 3, "Human Origins and the Fossil Record," of the new book Science and Human Origins, co-authored by Ann Gauger, Douglas Axe, and Casey Luskin. For details, see Discovery Institute Press.]

References Cited:

[116.] See for example Eric Delson, "One skull does not a species make," Nature, 389 (October 2, 1997): 445-46; Hawks et al., "Population Bottlenecks and Pleistocene Human Evolution," 2-22; Emilio Aguirre, "Homo erectus and Homo sapiens: One or More Species?," in 100 Years of Pithecanthropus: The Homo erectus Problem 171 Courier Forschungsinstitut Seckenberg, ed. Jens Lorenz (Frankfurt: Courier Forschungsinstitut Senckenberg, 1994), 333-339; Milford H. Wolpoff, Alan G. Thorne, Jan Jelínek, and Zhang Yinyun, "The Case for Sinking Homo erectus: 100 Years of Pithecanthropus is Enough!," in 100 Years of Pithecanthropus: The Homo erectus Problem 171 Courier Forschungsinstitut Seckenberg, ed. Jens Lorenz (Frankfurt: Courier Forschungsinstitut Senckenberg, 1994), 341-361.

[117.] See Hartwig-Scherer and Martin, "Was 'Lucy' more human than her 'child'? Observations on early hominid postcranial skeletons," 439-49.

[118.] Spoor, Wood, and Zonneveld, "Implications of early hominid labyrinthine morphology for evolution of human bipedal locomotion," 645-48.

[119.] William R. Leonard and Marcia L. Robertson, "Comparative Primate Energetics and Hominid Evolution," American Journal of Physical Anthropology, 102 (February, 1997): 265-81.

[120.] William R. Leonard, Marcia L. Robertson, and J. Josh Snodgrass, "Energetic Models of Human Nutritional Evolution," in Evolution of the Human Diet: The Known, the Unknown, and the Unknowable, ed. Peter S. Ungar (Oxford University Press, 2007), 344-59.

[121.] References for cranial capacities cited in Figure 3-11 are as follows: Gorilla: Stephen Molnar, Human Variation: Races, Types, and Ethnic Groups, 4th ed. (Upper Saddle River: Prentice Hall, 1998), 203. Chimpanzee: Molnar, Human Variation: Races, Types, and Ethnic Groups, 4th ed., 203. Australopithecus: Glenn C. Conroy, Gerhard W. Weber, Horst Seidler, Phillip V. Tobias, Alex Kane, Barry Brunsden, "Endocranial Capacity in an Early Hominid Cranium from Sterkfontein, South Africa," Science, 280 (June 12, 1998): 1730-31; Wood and Collard, "The Human Genus," 65-71. Homo habilis: Wood and Collard, "The Human Genus," 65-71. Homo erectus: Molnar, Human Variation: Races, Types, and Ethnic Groups, 4th ed., 203; Wood and Collard, "The Human Genus," 65-71. Neanderthals: Molnar, Human Variation: Races, Types, and Ethnic Groups, 4th ed., 203; Molnar, Human Variation: Races, Types, and Ethnic Groups, 5th ed., 189. Homo sapiens (modern man): Molnar, Human Variation: Races, Types, and Ethnic Groups, 4th ed., 203; E. I. Odokuma, P. S. Igbigbi, F. C. Akpuaka and U. B. Esigbenu, "Craniometric patterns of three Nigerian ethnic groups," International Journal of Medicine and Medical Sciences, 2 (February, 2010): 34-37; Molnar, Human Variation: Races, Types, and Ethnic Groups, 5th ed., 189.

[122.] Donald C. Johanson and Maitland Edey, Lucy: The Beginnings of Humankind (New York: Simon & Schuster, 1981), 144.

[123.] Ibid.

[124.] See Wood and Collard, "The Human Genus," 65-71.

[125.] Michael D. Lemonick, "A Bit of Neanderthal in Us All?," Time (April 25, 1999), accessed March 5, 2012, http://www.time.com/time/magazine/article/0,9171,23543,00.html.

[126.] Marc Kaufman, "Modern Man, Neanderthals Seen as Kindred Spirits," Washington Post (April 30, 2007), accessed March 5, 2012, http://www.washingtonpost.com/wp-dyn/content/article/2007/04/29/AR2007042901101_pf.html.

[127.] Joe Alper, "Rethinking Neanderthals," Smithsonian magazine (June, 2003), accessed March 5, 2012, http://www.smithsonianmag.com/science-nature/neanderthals.html.

[128.] Francesco d'Errico quoted in Alper, "Rethinking Neanderthals."

[129.] Molnar, Human Variation: Races, Types, and Ethnic Groups, 5th ed., 189.

[130.] B. Arensburg, A. M. Tillier, B. Vandermeersch, H. Duday, L. A. Schepartz, and. Y. Rak, "A Middle Palaeolithic human hyoid bone," Nature, 338 (April 27, 1989): 758-60.

[131.] Alper, "Rethinking Neanderthals"; Kate Wong, "Who were the Neandertals?," Scientific American (August, 2003): 28-37; Erik Trinkaus and Pat Shipman, "Neandertals: Images of Ourselves," Evolutionary Anthropology, 1 (1993): 194-201; Philip G. Chase and April Nowell, "Taphonomy of a Suggested Middle Paleolithic Bone Flute from Slovenia," Current Anthropology, 39 (August/October 1998): 549-53; Tim Folger and Shanti Menon, "... Or Much Like Us?," Discover Magazine, January, 1997, accessed March 5, 2012, http://discovermagazine.com/1997/jan/ormuchlikeus1026; C. B. Stringer, "Evolution of early humans," in The Cambridge Encyclopedia of Human Evolution, eds. Steve Jones, Robert Martin, and David Pilbeam (Cambridge: Cambridge University Press, 1992), 248.

[132.] Philip G. Chase and April Nowell, "Taphonomy of a Suggested Middle Paleolithic Bone Flute from Slovenia," Current Anthropology, 39 (August/October 1998): 549-553; Folger and Menon, "... Or Much Like Us?"

[133.] Notes in Nature, 77 (April 23, 1908): 587.

[134.] Metub Eren quoted in Jessica Ruvinsky, "Cavemen: They're Just Like Us," Discover Magazine (January, 2009), accessed March 5, 2012, http://discovermagazine.com/2009/jan/008.

[135.] Erik Trinkaus, quoted in Kaufman, "Modern Man, Neanderthals Seen as Kindred Spirits."

[136.] Erik Trinkaus and Cidália Duarte, "The Hybrid Child from Portugal," Scientific American (August, 2003): 32.

[137.] Rex Dalton, "Neanderthals may have interbred with humans," Nature news (April 20, 2010), accessed March 5, 2012, http://www.nature.com/news/2010/100420/full/news.2010.194.html.

[138.] Ibid.

[139.] Delson, "One skull does not a species make," 445-46.

[140.] Leslie Aiello quoted in Leakey and Lewin, Origins Reconsidered: In Search of What Makes Us Human, 196. See also Wood and Collard, "The Human Genus," 65-71.

[141.] Hartwig-Scherer, "Apes or Ancestors," 220.