Four billion years of evolution in six minutes - Prosanta Chakrabarty
- 216,241 Views
- 375 Questions Answered
- Best of Web
So how did fish evolve into walking land animals? A new genetic study from scientists at New York University reveals something surprising: Fish called “little skates” possess the genetic blueprint that allows for the right-left alternation pattern of locomotion that four-legged land animals use. Those genes were passed down from a common ancestor that lived 420 million years ago, long before the first vertebrates ever crawled from sea to shore. In other words, some animals may have had the neural pathways necessary for walking even before they lived on land.
What other misconceptions do we have about evolution? A popular misconception is that natural selection and evolution are the same thing- but natural selection is just one mechanism of the evolution process. Others include: organisms are always getting bigger and that evolution is about the origin of life.
Watch these recommended TED-Ed Lessons:
Myths and misconceptions about evolution
How does evolution really work? Actually, not how some of our common evolutionary metaphors would have us believe. For instance, it's species, not individual organisms, that adapt to produce evolution, and genes don't "want" to be passed on -- a gene can't want anything at all! Alex Gendler sets the record straight on the finer points of evolution.
What is the biggest single-celled organism?
The elephant is a creature of epic proportions — and yet, it owes its enormity to more than 1,000 trillion microscopic cells. And on the epically small end of things, there are likely millions of unicellular species, yet there are very few we can see with the naked eye. Why is that? Why don’t we get unicellular elephants? Or blue whales? Or brown bears? Murry Gans explains.
The amazing ways plants defend themselves
Plants are constantly under attack. They face threats ranging from microscopic fungi to small herbivores like caterpillars, up to large herbivores like elephants. But plants are ready, with a whole series of internal and external defenses that make them a less appealing meal — or even a deadly one. Valentin Hammoudi explains some of the fascinating ways that plants defend themselves.