5 ms·

It is essential when we look at deep time, or any sufficiently high-dimensional and detailed time series, to remember that we are only looking at a tiny slice.

It is essential when we look at deep time, or any sufficiently high-dimensional and detailed time series, to remember that we are only looking at a tiny slice. We always like to talk of "the tree of life", which might mislead folks into thinking that we get a clean cross-section of every branch of some high-dimensional tree. But, in truth, what we get is more like a tiny wedge cut out from a beanstalk with many central vines; we have only small leaves and cuttings from a mighty thick overgrowth of life.

d4mi3n 6y ago
Very true! I was also fascinated to find that it wasn't uncommon in the fossil record to have evolutionary lineages of species branch and later recombine. See: https://theconversation.com/dna-dating-how-molecular-clocks-are-refining-human-evolutions-timeline-65606 https://theconversation.com/dna-dating-how-molecular-clocks-... > DNA holds the story of our ancestry – how we’re related to the familiar faces at family reunions as well as more ancient affairs: how we’re related to our closest nonhuman relatives, chimpanzees; how Homo sapiens mated with Neanderthals; and how people migrated out of Africa, adapting to new environments and lifestyles along the way. And our DNA also holds clues about the timing of these key events in human evolution.
edmundsauto 6y ago
Also, some of the numbers don't seem that big in context. But this situation is 7 million years - plenty of time for evolution to make lots of changes! It just doesn't seem like that big of a gap when we talk about hundreds of millions of years. The scale is astonishing.
- lisper 6y ago
  Yep. 7 million years is a little under 0.2% of the age of the earth.
  - andi999 6y ago
    Although the first 20% were useless in terms of life.
- 082349872349872 6y ago
  In a much more recent, much smaller gap, horses originated in North America but died out there, only to be later reintroduced from the Old World. https://en.wikipedia.org/wiki/Evolution_of_the_horse https://en.wikipedia.org/wiki/Evolution_of_the_horse > "The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, ... Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago."

d4mi3n 6y ago

Very true! I was also fascinated to find that it wasn't uncommon in the fossil record to have evolutionary lineages of species branch and later recombine. See: https://theconversation.com/dna-dating-how-molecular-clocks-are-refining-human-evolutions-timeline-65606 https://theconversation.com/dna-dating-how-molecular-clocks-... > DNA holds the story of our ancestry – how we’re related to the familiar faces at family reunions as well as more ancient affairs: how we’re related to our closest nonhuman relatives, chimpanzees; how Homo sapiens mated with Neanderthals; and how people migrated out of Africa, adapting to new environments and lifestyles along the way. And our DNA also holds clues about the timing of these key events in human evolution.

edmundsauto 6y ago

Also, some of the numbers don't seem that big in context. But this situation is 7 million years - plenty of time for evolution to make lots of changes! It just doesn't seem like that big of a gap when we talk about hundreds of millions of years. The scale is astonishing.

lisper 6y ago
Yep. 7 million years is a little under 0.2% of the age of the earth.
- andi999 6y ago
  Although the first 20% were useless in terms of life.
082349872349872 6y ago
In a much more recent, much smaller gap, horses originated in North America but died out there, only to be later reintroduced from the Old World. https://en.wikipedia.org/wiki/Evolution_of_the_horse https://en.wikipedia.org/wiki/Evolution_of_the_horse > "The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, ... Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago."