[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

*To*: dinosaur@usc.edu*Subject*: Re: Extinction (of marbles)*From*: stevet@shelby.net (Stephen Throop)*Date*: Fri, 6 Dec 1996 12:57:57 -0500 (EST)*Reply-to*: stevet@shelby.net*Sender*: owner-dinosaur@usc.edu

While I only wish I understood hypergeometric distributions, it's reassuring to see that, using the same data, my more primitive computations yield the same results as those of Stan Friesen and Nathan Myhrvold. The difference in the data. The analogy of a group of 100 marbles among a total of 700 sounds similar to a group of 12 species among a total of 72. However, at 90% overall random extinction, the group extinction probability in the former case is only 0.000011, while in the latter case it's 0.262. (Is my math right?) John Schneiderman speaks of 799 known dinosaur genera. It sounds as if many hundreds of species must have been alive at one time. Is the extinction question about the gradual disappearance of hundreds of species or the faster disappearance of the last 12? Whether the explanation involves random probability or environmental "bullets" that preferred dinosaurs, the disappearance of a huge number of diverse species seems much harder to figure. - Stephen Throop

- Prev by Date:
**Re: Yet Another Extinction Theory Put Forth [joke]** - Next by Date:
**Re: dinosaur endothermy??** - Previous by thread:
**Re: Extinction (of marbles)** - Next by thread:
**Re: Extinction (of marbles)** - Indexes: