Where do the most genetically diverse people on Earth live?
🌍 The most genetically diverse people on Earth live in Africa.
Geneticists have discovered more than 3 mln previously undescribed genetic variants among Africans.
That diversity has fit well with the fossil evidence that the human species originated in Africa. It is known that when a new species, be it plant or animal, arises and spreads, genetic differences accumulate more in geographic regions where the species has been present longer. The more distant populations represent only a small subset of the genetic variation that arose nearer the center of origin.
The claim has even been made that East Africans are more genetically different from West Africans than Europeans are from Asians.
According to researchers:
✔️🇳🇦🇿🇦the southwestern coast of Africa-between today’s Namibia and South Africa-may be modern humanity’s homeland
✔️the oldest group in Africa, evolutionarily speaking, may be the San, or Bushmen.
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🌍 The most genetically diverse people on Earth live in Africa.
Geneticists have discovered more than 3 mln previously undescribed genetic variants among Africans.
That diversity has fit well with the fossil evidence that the human species originated in Africa. It is known that when a new species, be it plant or animal, arises and spreads, genetic differences accumulate more in geographic regions where the species has been present longer. The more distant populations represent only a small subset of the genetic variation that arose nearer the center of origin.
The claim has even been made that East Africans are more genetically different from West Africans than Europeans are from Asians.
According to researchers:
✔️🇳🇦🇿🇦the southwestern coast of Africa-between today’s Namibia and South Africa-may be modern humanity’s homeland
✔️the oldest group in Africa, evolutionarily speaking, may be the San, or Bushmen.
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How does the brain store memories?
🧠 In the brain, the hippocampus region, crucial for learning and memory, records each event in three different forms or “copies”.
These ‘”copies” are disseminated among different groups of neurons that arise at various stages during embryonic development.
1️⃣ The early-born neurons ensure the longevity of a memory creating a copy that, although initially weak, strengthens over time. This memory becomes more accessible to the brain long after its formation, allowing the preservation of memories in the long term.
2️⃣ The late-born neurons produce a memory copy that is very strong initially but fades quickly. This memory is easier to modify shortly after formation, allowing new information to be integrated or errors corrected.
3️⃣ The last group of neurons present an interesting compromise – a memory copy that remains stable over time.
These 3️⃣ memory copies function together, enhance the brain’s memory dynamics and reinforce its plasticity.
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🧠 In the brain, the hippocampus region, crucial for learning and memory, records each event in three different forms or “copies”.
These ‘”copies” are disseminated among different groups of neurons that arise at various stages during embryonic development.
1️⃣ The early-born neurons ensure the longevity of a memory creating a copy that, although initially weak, strengthens over time. This memory becomes more accessible to the brain long after its formation, allowing the preservation of memories in the long term.
2️⃣ The late-born neurons produce a memory copy that is very strong initially but fades quickly. This memory is easier to modify shortly after formation, allowing new information to be integrated or errors corrected.
3️⃣ The last group of neurons present an interesting compromise – a memory copy that remains stable over time.
These 3️⃣ memory copies function together, enhance the brain’s memory dynamics and reinforce its plasticity.
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Who left Paleozoic “dumbbells”?
All over the world, scientists find dumbbell-shaped fossils in rock outcrops that are called Bifungites and are not fossilized animals but burrows left in an extinct creature’s wake. ⬆️ Most are found in rocks from the Paleozoic era more than 300 million years ago.
🪱 Not long ago, Brazilian paleontologists, exploring the bed of the Sambito River in northeastern Brazil, found imprints of small worms inside Bifungites, indicating that these organisms produced them.⬆️
Researchers suggest that:
📌 the marine worms that made Bifungites belonged to a group called Annulitubus
📌 species in the group lived in the shallow part of the ocean near the shores of prehistoric supercontinents and dug burrows into the seabed.
📌 the Annulitubus worms made these burrows to protect themselves against savage storms or probing predators
📌 the worms potentially wedged themselves into the peculiar bulging or arrow-like ends of the chamber.
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All over the world, scientists find dumbbell-shaped fossils in rock outcrops that are called Bifungites and are not fossilized animals but burrows left in an extinct creature’s wake. ⬆️ Most are found in rocks from the Paleozoic era more than 300 million years ago.
🪱 Not long ago, Brazilian paleontologists, exploring the bed of the Sambito River in northeastern Brazil, found imprints of small worms inside Bifungites, indicating that these organisms produced them.⬆️
Researchers suggest that:
📌 the marine worms that made Bifungites belonged to a group called Annulitubus
📌 species in the group lived in the shallow part of the ocean near the shores of prehistoric supercontinents and dug burrows into the seabed.
📌 the Annulitubus worms made these burrows to protect themselves against savage storms or probing predators
📌 the worms potentially wedged themselves into the peculiar bulging or arrow-like ends of the chamber.
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When and why was the Sahara green?
✅ Records from ocean sediment show that the Green Sahara happens repeatedly in Earth's history.
✅ Sometime between 11,000 and 5,000 years ago, after the last ice age ended, about 9 mln square kilometers (3.5 mln square miles) of the modern Sahara Desert was a green place with lakes, where animals like elephants, hippos and antelopes feasted on thriving grasses and shrubs.
✅ The Green Sahara, also known as the African Humid Period, was caused by the Earth's constantly changing orbital rotation around its axis, a pattern that repeats itself every 23,000 years, researchers believe.
✅ Right now, the Northern Hemisphere is closest to the sun during the winter months, and during the Green Sahara, the Northern Hemisphere was closest to the sun during the summer. This led to an increase in solar radiation, in other words, heat, heat in summer, and created a low pressure system that ushered moisture from the Atlantic Ocean into the desert.
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✅ Records from ocean sediment show that the Green Sahara happens repeatedly in Earth's history.
✅ Sometime between 11,000 and 5,000 years ago, after the last ice age ended, about 9 mln square kilometers (3.5 mln square miles) of the modern Sahara Desert was a green place with lakes, where animals like elephants, hippos and antelopes feasted on thriving grasses and shrubs.
✅ The Green Sahara, also known as the African Humid Period, was caused by the Earth's constantly changing orbital rotation around its axis, a pattern that repeats itself every 23,000 years, researchers believe.
✅ Right now, the Northern Hemisphere is closest to the sun during the winter months, and during the Green Sahara, the Northern Hemisphere was closest to the sun during the summer. This led to an increase in solar radiation, in other words, heat, heat in summer, and created a low pressure system that ushered moisture from the Atlantic Ocean into the desert.
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Could the Sahara be green again and will Africa finally need its “Great Green Wall”?
🟢 Africa’s “Great Green Wall” initiative was launched to hold back the Sahara from expanding southward.
🟢 This year, after an unusual influx of rain, scientists have compared satellite imagery on September 12, 2024 (⬆️upper image), versus the same day in 2023 (⬆️lower image), and have seen that the southern Sahara’s vegetation reached much farther north in 2024.
ℹ️ Where the trade winds from each hemisphere meet near the Equator is a low-pressure zone, the intertropical convergence zone (ICZ).
🟢 According to researchers, most climate models suggest that the ICZ is the reason for Africa’s greening and farther northward “green” shifts in this zone could happen more frequently in the next decades.
🟢 So, in the distant future, it is very possible that the Sahara could turn green again and Africa, at least for a certain period of time, won’t need its “Great Green Wall”.
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🟢 Africa’s “Great Green Wall” initiative was launched to hold back the Sahara from expanding southward.
🟢 This year, after an unusual influx of rain, scientists have compared satellite imagery on September 12, 2024 (⬆️upper image), versus the same day in 2023 (⬆️lower image), and have seen that the southern Sahara’s vegetation reached much farther north in 2024.
ℹ️ Where the trade winds from each hemisphere meet near the Equator is a low-pressure zone, the intertropical convergence zone (ICZ).
🟢 According to researchers, most climate models suggest that the ICZ is the reason for Africa’s greening and farther northward “green” shifts in this zone could happen more frequently in the next decades.
🟢 So, in the distant future, it is very possible that the Sahara could turn green again and Africa, at least for a certain period of time, won’t need its “Great Green Wall”.
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What is a role of Saharan dust on hurricanes?
🌪🌧 Hurricanes, including tropical cyclone rainfall (TCR), are among the most destructive weather phenomena on Earth.
🌡💧Traditionally, sea surface temperature or humidity in the atmosphere were considered as the main factor controlling hurricane precipitation.
🏜❗️Now, scientists believe that Sahara dust plays a leading role on hurricane formation over the ocean, which affects weather in America.
ℹ️ Previous studies have found that Saharan dust transport may decline in the future and TCR could increase due to a climate change.
➡️⬅️According to a recent research, dust can however have competing effects on TCR.
✔️A dust particle can make ice clouds form more efficiently in the core of the hurricane, which can produce more precipitation.
✔️Dust can also block solar radiation and cool sea surface temperatures around a storm’s core, which weakens the TCR.
At high concentrations, dust shifts from boosting to suppressing rainfall.
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🌪🌧 Hurricanes, including tropical cyclone rainfall (TCR), are among the most destructive weather phenomena on Earth.
🌡💧Traditionally, sea surface temperature or humidity in the atmosphere were considered as the main factor controlling hurricane precipitation.
🏜❗️Now, scientists believe that Sahara dust plays a leading role on hurricane formation over the ocean, which affects weather in America.
ℹ️ Previous studies have found that Saharan dust transport may decline in the future and TCR could increase due to a climate change.
➡️⬅️According to a recent research, dust can however have competing effects on TCR.
✔️A dust particle can make ice clouds form more efficiently in the core of the hurricane, which can produce more precipitation.
✔️Dust can also block solar radiation and cool sea surface temperatures around a storm’s core, which weakens the TCR.
At high concentrations, dust shifts from boosting to suppressing rainfall.
Subscribe- t.me/askmenow
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