DR__Rise of the Animals David Attenborough Flashcards
Notochord: Gristly muscle which evolved into the first backbone.
mya=Million years ago
MYLLOKUNMINGIA: Earliest creature we know of that we can truly call a vertebrate. It used it’s entirely new Notochord [like a hard rod] to move in a new way, to swim like a fish (500mya).
Because Myllokunmingia could propel in the water, he could escape invertebrate predators. Since he survived against these attacks, his family tree poliferated into all the vertebrates of the animal kingdom we have today.
450 mya They moved out of the water. First plants, then worms and then the ancestors of insects.
As they moved to land, they needed a method to lift their bodies around on the land.
Scientists have found the missing link on the growth of “limbs” on “Ellesmere Island”, just west of Greenland.
The arrival of freshwater plants stimulated a surge in life around freshwater swamps.
Reptiles: Skin is covered with scales to seal in water, just like our skin called “Keratin”. Keratin is what makes up our finger and toe nails. The lizard skin is made from the same substance.
Amphibian skin is smooth and moist. They must lay eggs in water. Lizards lay eggs in a shell bringing the ocean to the egg.
The first Amphibans then evolved into reptiles.
Over 9,500 species of animals are now found on our planet.
Over 1,000 species of Dinosaurs found worldwide.
The link between Dinos and birds. Dinos evolved into birds.
Part 2:
500 mya fish evolved, then Amphibians, then Reptiles.
5,700 Mammals alive today. Mammals use fur to keep their body warm.
Reptiles can scarcely move at nightime because they are not getting energy from the sun.
MN: Think of Reptiles as running on a solar battery and needing a recharge to turn on the power. Mammals run on power from the Sun also, but get it through eating plants and other animals just like us humans do.
Reptiles can go days without food, while a mammal must eat daily.
The HADROCODIUM fossil mammal already had this 3 bone setup for the middle ear, like we humans do. The middle ear bones evolved from jawbones.
Eggs:
For a reptile, the egg has a large yolk to feed the embryo. By the time the egg is hatched, the baby reptile is almost fully developed and can hunt for food on its own.
Early egg laying mammals had a small yolk therefore the mammal had to squirt milk at the baby for nourishment/development for months.
Later mammals, like us, instead of laying the egg, would retain the egg inside its body and started the development there, so that the young was born alive.
MN: Then the mother would breast feed milk to the baby so it could finsh developing.
160 mya, Juramaia [a small Dinosaur] is the first mammal to carry her newborn/embryo in a womb. The Placenta [afterbirth] feeds the baby in the womb [lke us humans].
This umbilical cord feeds baby and Placenta removes waste products from the emybro.
These tiny mammals scampered around dinosaurs for millions of years until the Extinction of the large Dinos. Meteorite caused large Dinos to die. The fossil record of all Dions ends 65 mya.
Birds evolved from Dinos.
47 mya large fruits developed. Trees were so dense that the wind could not spread their seeds, so the plants covered seed in edible fruits. Birds eat fruit and poop out the seeds, thus the trees got repopulated.
Mammals then and now mostly see in B&W. B&W was helpful to see in the dark But reptiles and birds retained excellent color vision. At this same time the plants developed high colored fruit to attract birds to the fruit. fruit turned bright colors to signal birds and reptiles dinner time.
Mammals with B&W could not see the ripe fruit.
MN: To gain excellent night vision, animals must give up color and devote that part of their brain to night vision. Animals that see in color have poor night vision, like us. It is just a trade off on brain usage, as there is not room to have both.
Some mammals reacquired their old color vision and that is the family line humans came from, resulting in us seeing in color.
MN: Just think, if we came from another line like a dog or a deer, there would be no such thing as color to us humans.
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