Life on Mars: Lesson plan | Onestopenglish
However the hot times were created and sustained, Earth’s life reveled in the conditions. Similar to reptiles' beating the heat and migrating into the oceans, some mammals did the same thing about 200 million years later, and . Scientists were surprised when molecular studies found that with , and the is the closest living relative to whales. Whales evolved in and near India, beginning about 50 mya, when the earliest “whale” and lived near water. By 49 mya, . A few million years later , and by 41 mya they , for a transition from land to sea that “only” took eight million years. Whales quickly became dominant marine predators. However, sharks did not go quietly and began an arms race with whales, which culminated 28 mya in , the most fearsome marine predator ever: a shark reaching nearly 20 meters in length and weighing 50 metric tons. , as seen below ( in gray, great white shark in green, and next to that is a man taking a break in mouth). (Source: Wikimedia Commons)
Extraterrestrial life - Wikipedia
There are dry and wet seasons in the tropical rainforests where and live, and they must seasonably change their diets to adapt to available foods. Beyond those rainforests, seasonal variation is more pronounced and, once the easy meat was gone, people survived by engaging in the hunter-gatherer lifestyle familiar to today’s humans. A sexual division of labor existed: men hunted and women gathered. Men had the strength and speed required to hunt wary animals, particularly large game, while women were less mobile, partly due to caring for children.
Europe was a crucible for violence probably ever since the human conquest of Neanderthals, and evidence for warfare and mass violence increases as the timeline progressed from then. But going back to those , violence is not instinctual as much as calculated, and is a response to economic scarcity above all else. However, those early religious rituals were not only a method to form group cohesion; they were also a way to condition men to throw their lives away while trying to take the lives of others. The rituals and rites of passage for men were often extremely painful ordeals that conditioned them for the short life of a warrior, and forming highly contrasting in-group/out-group beliefs that facilitated killing other people. The portion of the human brain where emotions appear to be seated, in the , is no larger than in our great ape cousins. It is well-known that fear shuts down the neocortex, as animals prepare for fight-or-flight responses, and it is no different with humans. However, the response is much more dramatic with humans, with their huge neocortexes and frontal lobes. So the human response to fear is losing much of what makes humans seemingly sentient. Those religious rituals seem designed to bypass the neocortex and form a bridge to the limbic system where emotions rule. Religion seems to have arisen as a to warfare, but that will be explored in the next chapter, which covers the civilizing of humanity, which is the .
Energy and the Human Journey: Where We Have Been; …
has been a prominent hypothesis that posited that behaviorally modern humans suddenly appeared. It was once considered an abrupt event that began about 50-40 kya, but as new archeological finds are amassed, as well as recent advances in genetic research and other areas, the story is familiar. Although on the geological timescale the event was abrupt, radical, and unprecedented in life’s history on Earth, the “ramping” period seems to have lasted longer than initially thought. A likelier story is that in East Africa, which conforms to a . inherited culture and tools from their ancestors and continued along the path of inventing more complex technologies and techniques, exploiting new biomes, and reaching new levels of cognition. There does not seem to be any or development that needs to invoke divine or extraterrestrial intervention to explain the appearance and rise of . Some migrated past their African homeland during the of 130 kya to 114 kya and brought along their technology. Although they may have disappeared and perhaps became Neanderthal prey, vestiges of their fate are probably yet to be discovered. They may have contributed to the biological and technological wealth of Eurasian humans and may have begun to drive vulnerable species to extinction with their new tools and techniques. However, Africa remained the crucible of primate biological and technological innovation, as it almost always had to that time. By 70-60 kya, isolated African humans reached a level of sophistication called behavioral modernity. Art was in evidence, needles made clothes and other sophisticated possessions, and they mastered language, which was probably a unique trait among land animals. They made tools of a sophistication far advanced over other humans, which probably included projectile weapons that radically changed the terms of engagement with prey animals, predators, and other humans.