A new study estimates that the era of these hominids’ last common ancestor
CROWNING ROOTS An analysis of hominid tooth evolution, including specimens from Spanish Neandertals (top row)and pushes back the age of a frequent Neandertal-human ancestor to over 800,000 years back. The bottom row shows Homo sapiens teeth.
A. Gómez-Robles, Ana Muela and Jose Maria Bermudez de Castro
People and Neandertals separated by a common ancestor more than 800,000 years ago — much sooner than many researchers had thought.
This decision, published online May 15 in Science Advances, stems from an investigation of ancient fossilized Neandertal teeth found in a Spanish site called Sima de los Huesos. In shape and size, tooth implants changed Throughout development at a stable pace, states a paleoanthropologist at University College London, Aida Gómez-Robles. The Neandertal teeth, which date to approximately 430,000 years back, might have evolved their own distinctive shapes at a speed average of different hominids just if Neandertals originated between 800,000 and 1.2 million years ago, she finds.
Gómez-Robles’ study suggests that, if a frequent ancestor of present-day humans and Neandertals existed after around 1 million decades back,”there wasn’t enough time for Neandertal teeth to shift in the speed [teeth] do at different parts of the human family tree” in order to wind up looking like the Spanish finds, states palaeoanthropologist Bernard Wood of George Washington University in Washington, D.C.
Some investigators have thought that a species known as Homo heidelbergensis, believed to have occupied Africa and Europe, originated around 700,000 years back and gave rise to a ancestor of both Neandertals and Homo sapiens by approximately (************************************************************), respectively 00 years ago. Genetic evidence that Sima de los Huesos fossils originated from Neandertals raised suspicions that a common ancestor with H. sapiens existed well before that (SN Online: 3/14/16). Recent Neandertal DNA research set that common ancestor at between 550,000 and 765,000 years old. However, those results rest on estimates of \frequently genetic changes accumulated over time and just how fast.
With this molecular disagreement in mind, Gómez-Robles calculated that the speed at which eight early hominid species evolved modifications in tooth form. That allowed her to gauge the length of time it must have taken for Sima de los Huesos teeth to grow after Neandertals diverged from a common ancestor with H. sapiens.
Gómez-Robles used two possible evolutionary trees to the eight hominid species to estimate dental evolution prices. Aside from the Spanish Neandertals and Stone Age H. sapiens, teeth in her study came from African hominids dating to as early as 3.2 million decades back.
Transferring back the date of an evolutionary split between Neandertals and H. sapiens seems reasonable based on the newest data, says paleoanthropologist Aurélien Mounier of all Musée de l’Homme in Paris. The split’s timing could change, however, if further research modifies the Spanish fossils’ age, he states.
Additional Spanish hominid teeth relationship to almost 800,000 years back exhibit some Neandertal characteristics, encouraging the new study’s decisions, says New York University paleoanthropologist Shara Bailey. But it’s uncertain if Gómez-Robles’ emptiness that hominid teeth developed at a speed will maintain true, Bailey says.