Hachi's posts
Posted in it's literally just biology
Posted 5 years ago
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Early Homo fossils
H. habilis - shorter jaw and larger brain than australopiths, used stone tools
H. ergaster - even larger brain, long legs w/ hip joints for long distance walking, short and straight fingers (nonclimbers)
Lived in drier environments, more complex stone tools
Smaller teeth (ate more meat, less plant), meal prep?
Decrease in extent of sexual dimorphism (size of males vs. females) → more pair-bonding than male-male competition, long-term parental care of young
H. erectus - first to migrate out of Africa
Early Homo fossils
H. habilis - shorter jaw and larger brain than australopiths, used stone tools
H. ergaster - even larger brain, long legs w/ hip joints for long distance walking, short and straight fingers (nonclimbers)
Lived in drier environments, more complex stone tools
Smaller teeth (ate more meat, less plant), meal prep?
Decrease in extent of sexual dimorphism (size of males vs. females) → more pair-bonding than male-male competition, long-term parental care of young
H. erectus - first to migrate out of Africa
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
★
Bipedalism - naturally selected for as climate dried and forests gave way to savannahs
However, early hominins that were somewhat bipedal lived in mixed habitats, not savannahs
Bipedalism did not evolve in a linear fashion - some hominins could both walk and climb trees, others spent more time doing one, etc.
Hominins living in dry environments were the first to walk long distances on 2 legs
Bipedalism - naturally selected for as climate dried and forests gave way to savannahs
However, early hominins that were somewhat bipedal lived in mixed habitats, not savannahs
Bipedalism did not evolve in a linear fashion - some hominins could both walk and climb trees, others spent more time doing one, etc.
Hominins living in dry environments were the first to walk long distances on 2 legs
Posted in it's literally just biology
Posted 5 years ago
★
Australopiths - later hominins
“Gracile” australopiths - light feeding equipment → soft foods
A. africanus - fully bipedal, human-like hands/teeth, small-ish brain
A. afarensis - short, softball-sized brain and long lower jaw, long-ish arms enable arboreal locomotion, bipedal
“Robust” australopiths - sturdy skulls, powerful jaws, large teeth → for hard, tough food
Australopiths - later hominins
“Gracile” australopiths - light feeding equipment → soft foods
A. africanus - fully bipedal, human-like hands/teeth, small-ish brain
A. afarensis - short, softball-sized brain and long lower jaw, long-ish arms enable arboreal locomotion, bipedal
“Robust” australopiths - sturdy skulls, powerful jaws, large teeth → for hard, tough food
Posted in it's literally just biology
Posted 5 years ago
★
Hominins - extinct species closely related to humans, share some derived characters of humans
Reduced canine teeth, flat faces, somewhat upright/bipedal (foramen magnum hole is located underneath the skull → holds head directly above body, bipedal pelvis/leg/feet structure)
Not all derived characters of humans evolved in tight unison (eg. bipedalism and brain size)
Early hominins are not chimpanzees or evolved from them - chimpanzees and humans shared a common ancestor prior to diverging and acquiring their own derived characters
Human evolution is not linear or gradually progressive - H. sapiens are the only surviving member of a highly branched evolutionary tree
Hominins - extinct species closely related to humans, share some derived characters of humans
Reduced canine teeth, flat faces, somewhat upright/bipedal (foramen magnum hole is located underneath the skull → holds head directly above body, bipedal pelvis/leg/feet structure)
Not all derived characters of humans evolved in tight unison (eg. bipedalism and brain size)
Early hominins are not chimpanzees or evolved from them - chimpanzees and humans shared a common ancestor prior to diverging and acquiring their own derived characters
Human evolution is not linear or gradually progressive - H. sapiens are the only surviving member of a highly branched evolutionary tree
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
★
Monkeys - diurnal (daytime), social bands, originated in Africa/Asia, New World monkeys colonized South America and radiated separately → 2 groups
New World - prehensile tail, nostrils open to the sides, strictly arboreal
Old World - no prehensile tail, nostrils open downward, arboreal or ground-dwelling
Apes (includes humans) - diverged from Old World monkeys
Nonhuman apes: larger than monkeys, long arms, short legs, no tail, large brain and flexible behavior
Monkeys - diurnal (daytime), social bands, originated in Africa/Asia, New World monkeys colonized South America and radiated separately → 2 groups
New World - prehensile tail, nostrils open to the sides, strictly arboreal
Old World - no prehensile tail, nostrils open downward, arboreal or ground-dwelling
Apes (includes humans) - diverged from Old World monkeys
Nonhuman apes: larger than monkeys, long arms, short legs, no tail, large brain and flexible behavior
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
★
Eutherians - complex placentas, longer pregnancy (complete development in uterus)
Primates - hands and feet for grasping, flat nails and "fingerprints", large brain, short jaws, extensive parental care and social behavior
Early primates were tree-dwellers - required hands/feet to grasp branches, opposable thumbs, 2 forward-facing eyes enhance depth perception
Lemurs/lorises/bush babies, tarsiers, anthropoids
Eutherians - complex placentas, longer pregnancy (complete development in uterus)
Primates - hands and feet for grasping, flat nails and "fingerprints", large brain, short jaws, extensive parental care and social behavior
Early primates were tree-dwellers - required hands/feet to grasp branches, opposable thumbs, 2 forward-facing eyes enhance depth perception
Lemurs/lorises/bush babies, tarsiers, anthropoids
Posted in it's literally just biology
Posted 5 years ago
Posted in it's literally just biology
Posted 5 years ago
Posted in Dee's Exchange Thread! [Volts/Ohms/Art/Trade] Updated: 10th Aug'
Posted 5 years ago