Register | Sign In


Understanding through Discussion


EvC Forum active members: 48 (9179 total)
2 online now:
Newest Member: Jorge Parker
Post Volume: Total: 918,249 Year: 5,506/9,624 Month: 531/323 Week: 28/143 Day: 1/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Does Chen's work pose a problem for ToE?
NosyNed
Member
Posts: 9007
From: Canada
Joined: 04-04-2003


Message 44 of 84 (290207)
02-24-2006 7:25 PM
Reply to: Message 43 by jar
02-24-2006 7:16 PM


Worms and bugs
Something, Jar, that seems to get forgotten is, other than a couple of creatures, what Cambrian life would look like, to the untrained eye, is a bunch of very small "worms" and "bugs"
There is a big deal made of the fact that all the phyla were already represented. All that is needed for this is enough time for life to have diverged just enough to have the very basic characteristics that we use to classify phyla today. If one worm has a stiffen of cartilege like material down it's length and another does not they are, by today's definitions different phyla.
This is, to me, no "big deal" indeed given a very few million years to diverge. Of course, it appears we still have some 10's of Myrs to diverge. Perhaps the mystery is, like the preceding 3 Gyrs with mostly unicellular life, NOT how rapidly life "exploded" but rather why it took many 10's of millions of year too do so.
Pick a period of similar duration at a later date (and with lots of open niches to expand into) and you get the proliferation of mammals after the KT extinction as an example. I'd say that the later example looks more like an "explosion" and the pre-Cambrian example more like a slow smoulder.

This message is a reply to:
 Message 43 by jar, posted 02-24-2006 7:16 PM jar has replied

Replies to this message:
 Message 46 by jar, posted 02-24-2006 7:32 PM NosyNed has not replied

  
NosyNed
Member
Posts: 9007
From: Canada
Joined: 04-04-2003


Message 62 of 84 (290396)
02-25-2006 2:49 PM
Reply to: Message 61 by Modulous
02-25-2006 2:39 PM


some confusion about "advanced"
I don't see that. I see the problem being the time scale.
I think you are missing the confusion, Mod. rand seems to think that the bilaterians found much earlier than the Cambrian are actually more advanced than those found later in the Cambrian.

This message is a reply to:
 Message 61 by Modulous, posted 02-25-2006 2:39 PM Modulous has not replied

  
NosyNed
Member
Posts: 9007
From: Canada
Joined: 04-04-2003


Message 78 of 84 (290594)
02-26-2006 11:38 AM
Reply to: Message 77 by Chiroptera
02-26-2006 10:57 AM


Abundance
I doubt that they are found in "abundance".
Abundance is a kind of fuzzy term. Remember, Chiroptera, these dozen or so places where remarkable preservation has happened preserve even very, very small (microscopic and near) remains. In a small area there maybe many 1,000s of such creatures. That can be taken as "abundance". Of course, using that in this context isn't meaningful but it is typical.
Stepping back a bit it seems we have about a dozen sites spread over nearly a billion years. It would seem to me that something occuring on 100 million year intervals qualifies as "rare". If these samples (at 100 Myr intervals) capture 100,000 animals ("abundant"?) then we are getting (on average -- meaningless in this case but fun to calculate) about 1 animal per 1,000 years --- "rare" I would say (with how many animals living in the 1,000 years?--- really, really rare).
A silly argument but fun.

This message is a reply to:
 Message 77 by Chiroptera, posted 02-26-2006 10:57 AM Chiroptera has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024