Thursday, January 26, 2012
This makes me so happy. Its a cladogram of a collection at the American Museum of Natural History showing the evolution of vertebrates. The transition from aquatic environments to terrestrial is one of my very favorite things to think about, this highlights the story as well as demonstrates how DINOSAURS EVOLVED. Woah, yeah, dinosaurs. Whats even better, is that I'm learning the nitty gritty story behind all this in my classes this quarter.
The good stuff in evolutionary history starts once we have some solid evidence for life, I like solid evidence. 3.7 billion years ago (give or take a few million) there were plankton alive and doing what plankton do in Precambrian oceans. They were photosynthesizing happily, and then they reached the end of their little lives, died, and sank to the bottom of the ocean. Then they got fossilized, and discovered in modern Isua, Greenland. They aren't the first cells on Earth, but those lucky cells got fossilized and are the oldest fossilized evidence of life today.
From that point cellular life developed for THREE BILLION YEARS, gradually increasing in complexity to the point of mulitcellularity and sex. Cyanobacteria filled our atmosphere with free oxygen, and diversity radiated on our planet. Bacteria, Archea, and Eukaryotes have since been in competition for resources on Earth, acquiring truly astonishing diversity in every form. Below is amphibian predator Koskinonodon, formerly known as Buettneria perfecta, an animal who lived primarily in aquatic habitats but was capable of walking on land. Not a reptile, evolution is cool.
I'll post new knowledge and discoveries just as soon as I encounter them. Check back soon!