Four Billion Years, Three Billion Years, Million Years discussed on TEDTalks Science and Medicine


We evolved from monkeys why are there still monkeys well because we're not monkeys where fish now knowing you're a fish and not a monkey is actually really important to understanding where we came from i teach one of the largest ever legionary biology classes in the us and when my students finally understand why call him fish all the time then i know i'm getting my job done by always have to start my classes by dispelling some hardwired myths because without really knowing it many of us were taught evolution wrong for instance we're taught to say the theory of evolution there are actually many theories and just like the process itself the ones that best fit the data are the ones that survived to this day the one we know best is darwinian natural selection that's the process by which those organisms that best fit environment survive and get to reproduce while those that are less fit slowly die off and that's it evolution is a simple as that and it's a fact evolution is a fact as much as the theory of gravity you could prove it just as easily just need to look at your belly button that you share with other placental mammals or your backbone they share with other vertebrates where your dna they share with all other life on earth those traits didn't pop up in humans they were passed down from different ancestors to all their descendants not just us that's not really how we learn biology early on is it relearn plants and bacteria primitive things and fish give rise tam fabian nhs followed by reptiles mammals and then you get you this perfectly evolved creature at the end of the line the life doesn't evolve in a line and it doesn't end with us but we're always shown evelyn portrayed something like this a monkey and a chimpanzee some extinct humans all on a forward and steady march to becoming us but they don't become us any more than we would become them we're also not the goal of evolution why does it matter why do we need to understand lucien the right way well misunderstanding evolution has led to many problems but you can't ask that question that age old question where are we from without understanding evolution the right way misunderstanding it has led to many convoluted and corrupted views of how we should treat other life on earth and how we should treat each other in terms of race and gender so let's go back four billion years this is the single celled organism we all came from at i gave rise to other single cell life but these are still evolving to this day and some would say the archaic and bacteria that make up most of this group is the most successful on the planet they're certainly going to be here well after us about three billion years ago multicellular already volved this include your fungi and your plants and your animals the first animals to develop a backbone where fishes so technically overt brits are fishes so technically you an i are fish so don't say i didn't warn you one fish lineage came onto land and gave rise to among other things the mammals and reptiles some reptiles become birds some mammals become primates some primates become monkeys with tales and others become the great apes including a variety of human species so you see we didn't evolve from monkeys but we do share a common ancestor with them all the wildlife around us kept evolving more 'bacterial more fungi lots of fish fish fish if you couldn't tell yes they're my favorite group as life volve it also goes extinct most species just lasts for a few million years so you see most life on earth that we see around us today are about the same age as our species so it's hubris itself centered the think oh plants and bacteria primitive and we've been here for an evolutionary minute so we're somehow special think of life as being this book an unfinished book for sure we're just seeing the last few pages of each chapter if you look out on the eight million species that we share this planet with think of them all being four billion years of evolution there all the product of that think of us all as young leaves on this ancient and gigantic tree of life all of us connected by invisible branches not just to each other but two are extinct relatives our ancestors as a biologist i'm still trying to learn with others how how everyone's related to each other.

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