Advances in primate evolution.

[shunyadragon]

Over time the research advances and discoveries in evolution reveal the evolution is by the diversity within populations, and the diversity within these population show incremental small changes in the overall evolution of primats that lead to humans.

Source: https://phys.org/news/2020-11-newly-fossil-small-scale-evolutionary-extinct.html

Newly discovered fossil shows small-scale evolutionary changes in an extinct human species


by Talia Ogliore, Washington University in St. Louis


The discovery of a remarkably well-preserved fossil from the extinct human species Paranthropus robustus suggests rapid evolution during a turbulent period of local climate change, resulting in anatomical changes that previously were attributed to sex. Credit: Jesse Martin and David Strait

Males of the extinct human species Paranthropus robustus were thought to be substantially larger than females—much like the size differences seen in modern-day primates such as gorillas, orangutans and baboons. But a new fossil discovery in South Africa instead suggests that P. robustus evolved rapidly during a turbulent period of local climate change about 2 million years ago, resulting in anatomical changes that previously were attributed to sex.

An international research team including anthropologists at Washington University in St. Louis reported their discovery from the fossil-rich Drimolen cave system northwest of Johannesburg in the journal Nature Ecology & Evolution on Nov. 9.

"This is the type of phenomenon that can be hard to document in the fossil record, especially with respect to early human evolution," said David Strait, professor of biological anthropology in Arts & Sciences at Washington University.

The remarkably well-preserved fossil described in the paper was discovered by a student, Samantha Good, who participated in the Drimolen Cave Field School co-led by Strait.

Researchers already knew that the appearance of P. robustus in South Africa roughly coincided with the disappearance of Australopithecus, a somewhat more primitive early human, and the emergence in the region of early representatives of Homo, the genus to which modern people belong. This transition took place very rapidly, perhaps within only a few tens of thousands of years.

"The working hypothesis has been that climate change created stress in populations of Australopithecus leading eventually to their demise, but that environmental conditions were more favorable for Homo and Paranthropus, who may have dispersed into the region from elsewhere," Strait said. "We now see that environmental conditions were probably stressful for Paranthropus as well, and that they needed to adapt to survive."

The new specimen discovered at Drimolen, identified as DNH 155, is clearly a male but differs in important ways from other P. robustus previously discovered at the nearby site of Swartkrans—where most of the fossils of this species have been found.

Evolution within a species can be difficult to see in the fossil record. Changes may be subtle, and the fossil record is notoriously incomplete.

Usually, the fossil record reveals larger-scale patterns, such as when species or groups of species either appear in the fossil record or go extinct. So this Drimolen discovery provides a rarely seen window into early human evolution.

© Copyright Original Source

[rogue06]

Over time the research advances and discoveries in evolution reveal the evolution is by the diversity within populations, and the diversity within these population show incremental small changes in the overall evolution of primats that lead to humans.

Source: https://phys.org/news/2020-11-newly-fossil-small-scale-evolutionary-extinct.html

Newly discovered fossil shows small-scale evolutionary changes in an extinct human species


by Talia Ogliore, Washington University in St. Louis


The discovery of a remarkably well-preserved fossil from the extinct human species Paranthropus robustus suggests rapid evolution during a turbulent period of local climate change, resulting in anatomical changes that previously were attributed to sex. Credit: Jesse Martin and David Strait

Males of the extinct human species Paranthropus robustus were thought to be substantially larger than females—much like the size differences seen in modern-day primates such as gorillas, orangutans and baboons. But a new fossil discovery in South Africa instead suggests that P. robustus evolved rapidly during a turbulent period of local climate change about 2 million years ago, resulting in anatomical changes that previously were attributed to sex.

An international research team including anthropologists at Washington University in St. Louis reported their discovery from the fossil-rich Drimolen cave system northwest of Johannesburg in the journal Nature Ecology & Evolution on Nov. 9.

"This is the type of phenomenon that can be hard to document in the fossil record, especially with respect to early human evolution," said David Strait, professor of biological anthropology in Arts & Sciences at Washington University.

The remarkably well-preserved fossil described in the paper was discovered by a student, Samantha Good, who participated in the Drimolen Cave Field School co-led by Strait.

Researchers already knew that the appearance of P. robustus in South Africa roughly coincided with the disappearance of Australopithecus, a somewhat more primitive early human, and the emergence in the region of early representatives of Homo, the genus to which modern people belong. This transition took place very rapidly, perhaps within only a few tens of thousands of years.

"The working hypothesis has been that climate change created stress in populations of Australopithecus leading eventually to their demise, but that environmental conditions were more favorable for Homo and Paranthropus, who may have dispersed into the region from elsewhere," Strait said. "We now see that environmental conditions were probably stressful for Paranthropus as well, and that they needed to adapt to survive."

The new specimen discovered at Drimolen, identified as DNH 155, is clearly a male but differs in important ways from other P. robustus previously discovered at the nearby site of Swartkrans—where most of the fossils of this species have been found.

Evolution within a species can be difficult to see in the fossil record. Changes may be subtle, and the fossil record is notoriously incomplete.

Usually, the fossil record reveals larger-scale patterns, such as when species or groups of species either appear in the fossil record or go extinct. So this Drimolen discovery provides a rarely seen window into early human evolution.

© Copyright Original Source

Here is the abstract from the paper Drimolen cranium DNH 155 documents microevolution in an early hominin species:

Abstract


Paranthropus robustus is a small-brained extinct hominin from South Africa characterized by derived, robust craniodental morphology. The most complete known skull of this species is DNH 7 from Drimolen Main Quarry, which differs from P. robustus specimens recovered elsewhere in ways attributed to sexual dimorphism. Here, we describe a new fossil specimen from Drimolen Main Quarry, dated from approximately 2.04–1.95 million years ago, that challenges this view. DNH 155 is a well-preserved adult male cranium that shares with DNH 7 a suite of primitive and derived features unlike those seen in adult P. robustus specimens from other chronologically younger deposits. This refutes existing hypotheses linking sexual dimorphism, ontogeny and social behaviour within this taxon, and clarifies hypotheses concerning hominin phylogeny. We document small-scale morphological changes in P. robustus associated with ecological change within a short time frame and restricted geography. This represents the most highly resolved evidence yet of microevolutionary change within an early hominin species.

[shunyadragon]

Here is the abstract from the paper Drimolen cranium DNH 155 documents microevolution in an early hominin species:

Abstract


Paranthropus robustus is a small-brained extinct hominin from South Africa characterized by derived, robust craniodental morphology. The most complete known skull of this species is DNH 7 from Drimolen Main Quarry, which differs from P. robustus specimens recovered elsewhere in ways attributed to sexual dimorphism. Here, we describe a new fossil specimen from Drimolen Main Quarry, dated from approximately 2.04–1.95 million years ago, that challenges this view. DNH 155 is a well-preserved adult male cranium that shares with DNH 7 a suite of primitive and derived features unlike those seen in adult P. robustus specimens from other chronologically younger deposits. This refutes existing hypotheses linking sexual dimorphism, ontogeny and social behaviour within this taxon, and clarifies hypotheses concerning hominin phylogeny. We document small-scale morphological changes in P. robustus associated with ecological change within a short time frame and restricted geography. This represents the most highly resolved evidence yet of microevolutionary change within an early hominin species.

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