Millions of these

The picture was captioned, "Darwin's Folly"

Flickr

I saw the picture above on Facebook and thought that this would be the appropriate forum to write something. The chart points to a quadrupedal ape on the left and a Homo sapien on the right and alleges that there are "millions of these". Then it asks, "so where are the millions of these?"

This Facebook meme seems to be an edited picture of the one on the right. The farthest to the left is not named,  but it is probably not a chimpanzee (Pan troglodytes[1] and paniscus[2]).  Second on the chart is the Spanish "hominidos" which in English is the Family "Hominidae".  Within the Hominidae family are the genera: Pan (Chimps), Pongo (Orangutan), Gorilla, and Homo.[3]  Also included are extinct genera: Orrorin, Ardipithecus,  Australopithecus and Paranthropus.[4]  The second does not represent a genus or species, but an entire family.

Nature

With the discussion of the second, let us return to the first.   The skull marking the second is very similar to a chimpanzee, however the image has the second as a clear biped.  Still, the canines are also more prominent in Ardipithecus.  The feet also have a prominent thumb like toe that is also similar to the genus Ardipithecus.  So this is probably meant to emulate the Ardipiths.

What about the first one?  There are a couple of reasons that it is probably not meant to be a chimp.  One, human beings are not supposed to have evolved from chimps.  Chimps and Humans are hypothesized to share a common ancestor about 8 to 5 million years ago.  Fossil chimps were not even discovered until 2005.  They were dated at around half a million years old and were impossible "to say whether they belonged to the same species as modern chimps" "or to some unnamed, now extinct ancestor".[5]    Still, it is very unlikely that the image is trying to demonstrate that Ardipithecus,  Australopithecus, Paranthropus, and Homo all evolved from Pan or that Pan is older than Australopithecus.  Further, Dawkins noted in An Ancestor's Tale, "We must not assume, as many laymen do, that our ancestors were chimpanzees."[6]

The third from the left is the genus Australopithecus.   Despite Lucy (afarensis) being the most well known, there are at least six species of Australopith: anamensis, afarensis, bahrelghazali, africanus, garhi,[7] and sediba.  The previously mentioned Ardipithecus genus contains two species: kadabba and ramidus.[8]  Why is this important?  Do you remember the question?  "So where are the millions of these?"  There are only two known species of the genus Pan, yet there are about 300,000 troglodytes [9] and 20,000 paniscus [10].  Despite the fact that there are not "millions" of Pan left alive, the Facebook meme seems to suggest that six species of Australopiths alone could not produce a population of millions or be representative of a genus comparable in population to Pan.

The next skull on the chart is for the genus Paranthropus which contains three species: boisei, aethiopicus, and robustus [11].  The Paranthropus genus, however, is not represented by a figure.  Moving on, the next three are a select three species from the genus Homo.  The first is Homo habilis [12].  Habilis and Homo rudolfensis are thought to be among the earliest representatives of the genus.  Next is Homo erectus. [13]  More than 50 individuals were found at just one site and they have been found throughout Africa and Asia.[14] The final figure is Homo sapien.

Summing up, the animal to the left is probably not a chimpanzee.  Even if it is, I hope the point is clear, even with only showing three species from Homo, there are abundant fossils for that genus.  Also the other two genera cited also have abundant fossils.  Any of these genera dwarf the chimpanzee fossil record by a mile.  Also the Australopithecus, Paranthropus, and Homo genera are represented by more species than the genus Pan.

PS - The meme on Facebook (with over 300 shares) is captioned "Darwin's Folly".  When Darwin wrote Origin of the Species (1859) and Descent of Man (1871), only Homo sapiens were known to science.  Darwin hypothesized the existence of the other species.  This seems more like a successful prediction of Darwin's theory rather than a folly.