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FIGURE 13. The data suggests that Neanderthals, like modern humans, were able to speak. Unlike all other great apes, humans do not have air sacs on their vocal tracts. In the great apes these sacs allow them to make loud bellows. However the air sacs also make it impossible to produce different vowel sounds. It is only because human ancestors lost these sacs that modern humans are able to talk. Analysis suggests that the air sacs were lost before humans diverged from their Neanderthal cousins, suggesting the Neanderthals could also speak (FIGURE 13).

Figure 13 The data suggests that Neanderthals, like modern humans, were able to speak. Unlike all other great apes, humans do not have air sacs on their vocal tracts. In the great apes these sacs allow them to make loud bellows. However the air sacs also make it impossible to produce different vowel sounds. It is only because human ancestors lost these sacs that modern humans are able to talk. Analysis suggests that the air sacs were lost before humans diverged from their Neanderthal cousins, suggesting the Neanderthals could also speak (FIGURE 13).

Related Figures (14)

The common ancestor of Humans, chimpanzees and gorillas is an unknown extinct ape. In this ancestor between fifteen and ten million years ago, a gene called RNF213 began evolving rapidly. This may have boosted the flow of blood to the brain by widening the carotid artery (FIGURE 2). In humans, RNF213 mutations cause Moyamoya disease, in which the artery is too narrow.
The common ancestor of Humans, chimpanzees and gorillas is an unknown extinct ape. In this ancestor between fifteen and ten million years ago, a gene called RNF213 began evolving rapidly. This may have boosted the flow of blood to the brain by widening the carotid artery (FIGURE 2). In humans, RNF213 mutations cause Moyamoya disease, in which the artery is too narrow.
FIGURE 1. A social group of Gelada Primates. Barrowclough, D. 2015. A Short Guide to the Evolution of Human Intelligence: A Timeline for the Evolution of Homo Sapien Over the Last Sixty Million Years. Cambridge: Red Dagger Press
FIGURE 1. A social group of Gelada Primates. Barrowclough, D. 2015. A Short Guide to the Evolution of Human Intelligence: A Timeline for the Evolution of Homo Sapien Over the Last Sixty Million Years. Cambridge: Red Dagger Press
Our ancestors split from their chimp-like relatives between thirteen and seven million years ago (FIGURE 3). At first, externally they would have looked similar, but within their cells, changes were taking place. Following the split, both the ASPM and ARHGAP11B genes, and a region called HAR1 began to change. It is not completely clear what impact the changes had, but the HAR1 region and ARHGAP11B are involved in the growth of the cerebral cortex. This suggests that the gene mutations were linked to cognitive changes. BRAIN POWER
Our ancestors split from their chimp-like relatives between thirteen and seven million years ago (FIGURE 3). At first, externally they would have looked similar, but within their cells, changes were taking place. Following the split, both the ASPM and ARHGAP11B genes, and a region called HAR1 began to change. It is not completely clear what impact the changes had, but the HAR1 region and ARHGAP11B are involved in the growth of the cerebral cortex. This suggests that the gene mutations were linked to cognitive changes. BRAIN POWER
After the human lineage split from that of chimpanzees, which occurred within the last seven million years, two genes mutated: SLC2A1 and SLC2A4. Both of these genes build proteins that transport glucose in and out of cells. The tweaks made by the genetic changes may have had the effect of diverting glucose away from muscles and into the early hominins' brains. In the brain the glucose would provided more energy boosting the brains, and allowing them to increase in size (FIGURE 4).
After the human lineage split from that of chimpanzees, which occurred within the last seven million years, two genes mutated: SLC2A1 and SLC2A4. Both of these genes build proteins that transport glucose in and out of cells. The tweaks made by the genetic changes may have had the effect of diverting glucose away from muscles and into the early hominins' brains. In the brain the glucose would provided more energy boosting the brains, and allowing them to increase in size (FIGURE 4).
Compared to other apes humans can't bite very hard, because they have weak jaw muscles (FIGURE 6). This is down to a mutation in the MYH16 gene, which controls the production of muscle, which happened between 5.3 and 2.4 million years ago. The smaller jaws could have freed up space for the brain to grow.
Compared to other apes humans can't bite very hard, because they have weak jaw muscles (FIGURE 6). This is down to a mutation in the MYH16 gene, which controls the production of muscle, which happened between 5.3 and 2.4 million years ago. The smaller jaws could have freed up space for the brain to grow.
The hands of Homo sapiens are unusually dextrous compared to other primates (FIGURE 5). This dexterity allowed them to develop early stone tool technologies and later writing. It appears from genetic studies that this adaptation is at least in part due to mutations in an area of DNA called HACNS1. During the last seven million years, since humans diverged from chimpanzees, this area of DNA has evolved rapidly. Our current state of knowledge leaves it unclear as to the precise function(s) of HACNS1, but it is active in the arms and hands as they develop, which suggests that it is linked to manual dexterity in Homo sapiens.
The hands of Homo sapiens are unusually dextrous compared to other primates (FIGURE 5). This dexterity allowed them to develop early stone tool technologies and later writing. It appears from genetic studies that this adaptation is at least in part due to mutations in an area of DNA called HACNS1. During the last seven million years, since humans diverged from chimpanzees, this area of DNA has evolved rapidly. Our current state of knowledge leaves it unclear as to the precise function(s) of HACNS1, but it is active in the arms and hands as they develop, which suggests that it is linked to manual dexterity in Homo sapiens.
Between three and four million years ago human ancestors lost almost all their body hair (FIGURE 8). It i: by no means clear why this occurred, but the development can be dated by the appearance of pubic lice The lice evolved three to four million years ago, and since they could only infest our ancestors once thei other body hair was gone we can be sure that almost all body hair had been shed by this time. Exposed tc the Sun, the skin darkened, and thus all our ancestors were black, until comparatively recently whet some modern humans left the tropics, and adapted to more northerly latitudes by losing skir pigmentation.
Between three and four million years ago human ancestors lost almost all their body hair (FIGURE 8). It i: by no means clear why this occurred, but the development can be dated by the appearance of pubic lice The lice evolved three to four million years ago, and since they could only infest our ancestors once thei other body hair was gone we can be sure that almost all body hair had been shed by this time. Exposed tc the Sun, the skin darkened, and thus all our ancestors were black, until comparatively recently whet some modern humans left the tropics, and adapted to more northerly latitudes by losing skir pigmentation.
Homo sapiens’ oldest ape-like ancestors mostly ate fruit, but the later species of Australopithecus diversified their diet, a process that lasted from 3.5 to 1.8 million years ago (FIGURE 7) As well as eating a wider range of plants, such as grasses, they also ate a lot more meat. Archaeological evidence shows that they even used stone tools to butcher meat. Meat is more calorific than fruit for the same weight, and requires less chewing to digest than vegetables and grasses. The additional calories provided by meat allowed human ancestors to increase the size of their brain, which consumes large amounts of energy, as well as reducing the size of their jaw muscles.
Homo sapiens’ oldest ape-like ancestors mostly ate fruit, but the later species of Australopithecus diversified their diet, a process that lasted from 3.5 to 1.8 million years ago (FIGURE 7) As well as eating a wider range of plants, such as grasses, they also ate a lot more meat. Archaeological evidence shows that they even used stone tools to butcher meat. Meat is more calorific than fruit for the same weight, and requires less chewing to digest than vegetables and grasses. The additional calories provided by meat allowed human ancestors to increase the size of their brain, which consumes large amounts of energy, as well as reducing the size of their jaw muscles.
FIGURE 9. Brain synapses firing. Of all the genetic changes that made humans what they are, it is those that are linked to intelligence that are of most significance. Research shows that a gene called SRGAP2 was duplicated no less than three times. As a consequence, the ancestors of Homo sapiens had several copies, some of which appear to have evolved freely. One of the mutated copies turned out to be better than the original as it caused brain cells to extrude more spines, allowing them to form more synaptic connections, and thus increase cognitive ability (FIGURE 9).
FIGURE 9. Brain synapses firing. Of all the genetic changes that made humans what they are, it is those that are linked to intelligence that are of most significance. Research shows that a gene called SRGAP2 was duplicated no less than three times. As a consequence, the ancestors of Homo sapiens had several copies, some of which appear to have evolved freely. One of the mutated copies turned out to be better than the original as it caused brain cells to extrude more spines, allowing them to form more synaptic connections, and thus increase cognitive ability (FIGURE 9).
FIGURE 10. Homo Habilis, reconstruction and fossil skull. Modern humans belong to the ‘genus’ (group) of animals known as Homo. The oldest known Homo fossil, found in Ethiopia, is 2.8 million years old (FIGURE 10). The first species was probably Homo habilis, although this has been disputed, and new fossil discoveries are continually made. Compared to their ancestors, these new hominins had much larger brains.
FIGURE 10. Homo Habilis, reconstruction and fossil skull. Modern humans belong to the ‘genus’ (group) of animals known as Homo. The oldest known Homo fossil, found in Ethiopia, is 2.8 million years old (FIGURE 10). The first species was probably Homo habilis, although this has been disputed, and new fossil discoveries are continually made. Compared to their ancestors, these new hominins had much larger brains.
Figure 11. Anatomy of pregnant female Homo sapien. The large head of the baby has to pass through the narrow birth canal, causing potential danger to both mother and infant. For Homo sapiens, childbirth is difficult and dangerous. Unlike other primates, human mothers almost always need help when giving birth. This is because adaptations to walking on two legs have included a narrowing of the pelvic canal, leaving less space for the baby to pass through during birth (FIGURE 11). Furthermore, the increase in brain size, discussed above, has lead to an increase in the size of the head in modern humans. In order to partially compensate for the increased difficulty of birth, human babies are born whilst still small and helpless, and so need more and longer nursing care compared to other primates.
Figure 11. Anatomy of pregnant female Homo sapien. The large head of the baby has to pass through the narrow birth canal, causing potential danger to both mother and infant. For Homo sapiens, childbirth is difficult and dangerous. Unlike other primates, human mothers almost always need help when giving birth. This is because adaptations to walking on two legs have included a narrowing of the pelvic canal, leaving less space for the baby to pass through during birth (FIGURE 11). Furthermore, the increase in brain size, discussed above, has lead to an increase in the size of the head in modern humans. In order to partially compensate for the increased difficulty of birth, human babies are born whilst still small and helpless, and so need more and longer nursing care compared to other primates.
Something else that separates Homo from other primates and from its closest cousins is the ability to control fire (FIGURE 12). It is not known exactly when human ancestors first learned to control fire. The oldest direct evidence comes from Wonderwerk Cave in South Africa, which contains ashes and burned bones from one million years ago, tut there is evidence hominins were processing, and possibly cooking, food even earlier.
Something else that separates Homo from other primates and from its closest cousins is the ability to control fire (FIGURE 12). It is not known exactly when human ancestors first learned to control fire. The oldest direct evidence comes from Wonderwerk Cave in South Africa, which contains ashes and burned bones from one million years ago, tut there is evidence hominins were processing, and possibly cooking, food even earlier.
A few people have mutations in a gene called FOXP2. As a result they struggle to grasp grammar anc pronounce words. That suggests FOXP2 is crucial for learning and using language. The modern FOXP2 evolved in the common ancestor of humans and Neanderthals, about half a million years ago, as Neanderthal FOXP2 looks just like ours (FIGURE 14).
A few people have mutations in a gene called FOXP2. As a result they struggle to grasp grammar anc pronounce words. That suggests FOXP2 is crucial for learning and using language. The modern FOXP2 evolved in the common ancestor of humans and Neanderthals, about half a million years ago, as Neanderthal FOXP2 looks just like ours (FIGURE 14).
FIGURE 15. One of the most plentiful supplies of starch in the modern diet is wheat. Saliva contains the enzyme amylase, which digests starch (FIGURE 15). This enzyme is made by the AMY1 gene. Studies have shown that modern humans, whose ancestors were farmers, have more copies of the AMY1 gene than people whose ancestors continued with a hunter-gatherer-fisher way of life. The ability to digest starch is essential to an urban way of life, and the increase in frequency of AMY1 may have helped start farming, settled villages and modern societies, all of which have occurred since the end of the last ice age only ten thousand years ago.
FIGURE 15. One of the most plentiful supplies of starch in the modern diet is wheat. Saliva contains the enzyme amylase, which digests starch (FIGURE 15). This enzyme is made by the AMY1 gene. Studies have shown that modern humans, whose ancestors were farmers, have more copies of the AMY1 gene than people whose ancestors continued with a hunter-gatherer-fisher way of life. The ability to digest starch is essential to an urban way of life, and the increase in frequency of AMY1 may have helped start farming, settled villages and modern societies, all of which have occurred since the end of the last ice age only ten thousand years ago.
Related topics:
GeneticsArchaeologyPrehistoric ArchaeologyAnthropologyBiological AnthropologyHuman EvolutionHuman GeneticsEvolutionary Dynamics in Human & Animal CulturesBehaviour (Human Evolution)Origins of Agriculture
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