8 ms·

Fossil footprints reveal humans in North America earlier than previously thought

99 points by mvgoogler 5y ago

Ajay-p 5y ago
What are the conditions under which these footprints were made, and how have they managed to survive undisturbed for so long?
- joelhoffman 5y ago
  USGS describes the site as a "large playa," and the Science abstract says they were "stratigraphically constrained and bracketed by seed layers" so I interpret that to mean they were made in wet sand and buried under layers of more sand.
- PaulDavisThe1st 5y ago
  From the NYT article about this: > The footprints were formed when people strode over damp, sandy ground on the margin of a lake. Later, sediments gently filled in the prints, and the ground hardened. But subsequent erosion resurfaced the prints. In some cases, the impressions are only visible when the ground is unusually wet or dry — otherwise they are invisible to the naked eye. But ground-penetrating radar can reveal their three-dimensional structure, including the heels and toes.
changoplatanero 5y ago
No picture of the footprints?
- missinfo 5y ago
  NYT has photos here: https://www.nytimes.com/2021/09/23/science/ancient-footprints-ice-age.html https://www.nytimes.com/2021/09/23/science/ancient-footprint...
  - pomian 5y ago
    Cool. You get to see the image and even save it, before the pay wall appears. And an image is truly worth a 1000 words.
    - 230149dsad232jj 5y ago
      I guess since you are unwilling to pay for NY Times journalism, the image is worth 1000 * 0. Which is fine, I just thought your choice of wording was amusing.
      - pvaldes 5y ago
        (I wonder how much had paid NY Times to the scientists that discovered the footprints. If you want support science shouldn't you see the photos and read it in the scientific journal instead?)
      - rad_gruchalski 5y ago
        Oh, I am willing to pay. What I’m not willing to do is to pay $10 here, $10 there, $10 over there and maybe another $10 somewhere else.
lkrubner 5y ago
My dad used to make this argument: of all the millions of footprints that humans made, after arriving in North America, what is the likelihood that we found the very first of those footprints? The point is, whatever evidence we find, it's unreasonable to think that evidence we've found is the first evidence that existed, so we have to assume the real arrival was a bit before that. When we had evidence of humans arriving 17,000 years ago, it was reasonable to assume humans really arrived 21,000 years ago. When we have evidence of people arriving 23,000 years ago, you have to assume people really arrived 25,000 years ago. There may come a point, centuries from now, when our evidence feels comprehensive, at which point the error estimate can shrink. But modern archeology is barely 100 years old and most subject areas are still under-studied, so error estimates need to remain large, for now, especially for the prehistoric era. (Obviously error estimates are much smaller for the historic era, where we have a relative abundance of evidence.)
- kwonkicker 5y ago
  Technically true but wrong. If your oldest Facebook post is from 2015, how likely is it that you've been using the internet before 2005?! Archeologists are very smart people in their own right, some are much smarter than we are. They do consider everything that we think they haven't. Let's give some benefit of the doubt to our fellow researchers.
  - neffy 5y ago
    Some background on this, there is a long standing back to the late 20th century - and to those of us outside the field darkly funny - controversy within this particular scientific community on when the first humans arrived, which can be broadly googled by searches for "Clovis man controversy". Sure archeologists are very smart people, and like all other very smart people, can still be caught on the wrong side of history as new evidence piles up against existing theories.
  - User23 5y ago
    > If your oldest Facebook post is from 2015, how likely is it that you've been using the internet before 2005?! Who knows. It could be that person has been using the Internet for a very long time and is thus a late adopter of Facebook due to preferring to do things the old way. It could also be a person who started using the Internet in 2015. GP's point that we really can't conclude anything beyond a lower bound isn't falsified by your example
Causality1 5y ago
Expect this to get messy. There are powerful interest groups whose self-identity relies on Clovis culture and its descendants being the first peoples of the Americas.
- AlotOfReading 5y ago
  Who are these interest groups? My understanding is that pre-Clovis is completely established beyond any semblance of reasonable doubt, so they're 30+ years behind the times.
  - jandrewrogers 5y ago
    From what my archaeologist friends in North America tell me, the interest group is modern native Americans. They are the direct descendants of the Clovis culture. Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land, which would be weakened or voided if substantial scientific evidence established that they simply replaced a prior human culture. Due to a perverse set of incentives, native American interest groups use these unique rights to actively interfere with archaeological research that might undermine their claims to being the first occupants of the land. While it has not stopped pre-Clovis research, it has greatly impeded it. While the scientific evidence strongly suggests a pre-Clovis people, the legal theories and legislation that presume this is not the case are still active. These are evaluated on a case by case basis currently.
    - PaulDavisThe1st 5y ago
      > Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land Please point to these rights and legal theories. Do you just mean NAGPRA? As far as I know, whatever legal rights any native American people have in the Americas at this point in time are based purely on them being here when Europeans arrived near the start of the 16th century. Whether they had been the occupants for 400 years or 40,000 years wouldn't make any difference to the treaties that were signed (and generally abrogated).
esalman 5y ago
White Sands National Park is absolutely gorgeous, I'd highly recommend visiting that place to anybody touring the southwestern USA.
antiquark 5y ago
Is it just me, or do those footprints look fake? As if, they were sculpted by an artist?
deleted 5y ago
[deleted]
8bitsrule 5y ago
Alaskan cave with a human-worked jaw bone of a Yukon horse, radiocarbon dated to 24,000 BP c. 1979; confirmed in 2017. [https://en.wikipedia.org/wiki/Bluefish_Caves https://en.wikipedia.org/wiki/Bluefish_Caves] [https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169486 https://journals.plos.org/plosone/article?id=10.1371/journal...] [https://www.smithsonianmag.com/science-nature/jacques-cinq-mars-bluefish-caves-scientific-progress-180962410/ https://www.smithsonianmag.com/science-nature/jacques-cinq-m...]
- shusaku 5y ago
  The linked article has a footprint in New Mexico 23,000 years ago, whereas your link is in the top of Alaska at 24,000 years ago. It sounds like filling in the middle will be quite exciting!

99 points by mvgoogler 5y ago

What are the conditions under which these footprints were made, and how have they managed to survive undisturbed for so long?

joelhoffman 5y ago
USGS describes the site as a "large playa," and the Science abstract says they were "stratigraphically constrained and bracketed by seed layers" so I interpret that to mean they were made in wet sand and buried under layers of more sand.
PaulDavisThe1st 5y ago
From the NYT article about this: > The footprints were formed when people strode over damp, sandy ground on the margin of a lake. Later, sediments gently filled in the prints, and the ground hardened. But subsequent erosion resurfaced the prints. In some cases, the impressions are only visible when the ground is unusually wet or dry — otherwise they are invisible to the naked eye. But ground-penetrating radar can reveal their three-dimensional structure, including the heels and toes.

changoplatanero 5y ago

No picture of the footprints?

missinfo 5y ago
NYT has photos here: https://www.nytimes.com/2021/09/23/science/ancient-footprints-ice-age.html https://www.nytimes.com/2021/09/23/science/ancient-footprint...
- pomian 5y ago
  Cool. You get to see the image and even save it, before the pay wall appears. And an image is truly worth a 1000 words.
  - 230149dsad232jj 5y ago
    I guess since you are unwilling to pay for NY Times journalism, the image is worth 1000 * 0. Which is fine, I just thought your choice of wording was amusing.
    - pvaldes 5y ago
      (I wonder how much had paid NY Times to the scientists that discovered the footprints. If you want support science shouldn't you see the photos and read it in the scientific journal instead?)
    - rad_gruchalski 5y ago
      Oh, I am willing to pay. What I’m not willing to do is to pay $10 here, $10 there, $10 over there and maybe another $10 somewhere else.

lkrubner 5y ago

My dad used to make this argument: of all the millions of footprints that humans made, after arriving in North America, what is the likelihood that we found the very first of those footprints? The point is, whatever evidence we find, it's unreasonable to think that evidence we've found is the first evidence that existed, so we have to assume the real arrival was a bit before that. When we had evidence of humans arriving 17,000 years ago, it was reasonable to assume humans really arrived 21,000 years ago. When we have evidence of people arriving 23,000 years ago, you have to assume people really arrived 25,000 years ago. There may come a point, centuries from now, when our evidence feels comprehensive, at which point the error estimate can shrink. But modern archeology is barely 100 years old and most subject areas are still under-studied, so error estimates need to remain large, for now, especially for the prehistoric era. (Obviously error estimates are much smaller for the historic era, where we have a relative abundance of evidence.)

kwonkicker 5y ago
Technically true but wrong. If your oldest Facebook post is from 2015, how likely is it that you've been using the internet before 2005?! Archeologists are very smart people in their own right, some are much smarter than we are. They do consider everything that we think they haven't. Let's give some benefit of the doubt to our fellow researchers.
- neffy 5y ago
  Some background on this, there is a long standing back to the late 20th century - and to those of us outside the field darkly funny - controversy within this particular scientific community on when the first humans arrived, which can be broadly googled by searches for "Clovis man controversy". Sure archeologists are very smart people, and like all other very smart people, can still be caught on the wrong side of history as new evidence piles up against existing theories.
- User23 5y ago
  > If your oldest Facebook post is from 2015, how likely is it that you've been using the internet before 2005?! Who knows. It could be that person has been using the Internet for a very long time and is thus a late adopter of Facebook due to preferring to do things the old way. It could also be a person who started using the Internet in 2015. GP's point that we really can't conclude anything beyond a lower bound isn't falsified by your example

Causality1 5y ago

Expect this to get messy. There are powerful interest groups whose self-identity relies on Clovis culture and its descendants being the first peoples of the Americas.

AlotOfReading 5y ago
Who are these interest groups? My understanding is that pre-Clovis is completely established beyond any semblance of reasonable doubt, so they're 30+ years behind the times.
- jandrewrogers 5y ago
  From what my archaeologist friends in North America tell me, the interest group is modern native Americans. They are the direct descendants of the Clovis culture. Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land, which would be weakened or voided if substantial scientific evidence established that they simply replaced a prior human culture. Due to a perverse set of incentives, native American interest groups use these unique rights to actively interfere with archaeological research that might undermine their claims to being the first occupants of the land. While it has not stopped pre-Clovis research, it has greatly impeded it. While the scientific evidence strongly suggests a pre-Clovis people, the legal theories and legislation that presume this is not the case are still active. These are evaluated on a case by case basis currently.
  - PaulDavisThe1st 5y ago
    > Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land Please point to these rights and legal theories. Do you just mean NAGPRA? As far as I know, whatever legal rights any native American people have in the Americas at this point in time are based purely on them being here when Europeans arrived near the start of the 16th century. Whether they had been the occupants for 400 years or 40,000 years wouldn't make any difference to the treaties that were signed (and generally abrogated).

esalman 5y ago

White Sands National Park is absolutely gorgeous, I'd highly recommend visiting that place to anybody touring the southwestern USA.

antiquark 5y ago

Is it just me, or do those footprints look fake? As if, they were sculpted by an artist?

deleted 5y ago

[deleted]

8bitsrule 5y ago

Alaskan cave with a human-worked jaw bone of a Yukon horse, radiocarbon dated to 24,000 BP c. 1979; confirmed in 2017. [https://en.wikipedia.org/wiki/Bluefish_Caves https://en.wikipedia.org/wiki/Bluefish_Caves] [https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169486 https://journals.plos.org/plosone/article?id=10.1371/journal...] [https://www.smithsonianmag.com/science-nature/jacques-cinq-mars-bluefish-caves-scientific-progress-180962410/ https://www.smithsonianmag.com/science-nature/jacques-cinq-m...]

shusaku 5y ago
The linked article has a footprint in New Mexico 23,000 years ago, whereas your link is in the top of Alaska at 24,000 years ago. It sounds like filling in the middle will be quite exciting!