[Taxacom] What is Homo sapiens

[Adam Cotton]

----- Original Message ----- 
From: "John Grehan" <calabar.john at gmail.com>
To: "Richard Zander" <Richard.Zander at mobot.org>
Cc: "taxacom" <taxacom at mailman.nhm.ku.edu>
Sent: Friday, June 01, 2018 10:43 PM
Subject: Re: [Taxacom] What is Homo sapiens


> All systematic arrangements may be viewed as artifacts of a particular
> method - whether cladistic, phenetic, Zandean etc. Whether or not they
> model anything in nature is a matter of individual interpretation. Just
> because cladistic methods may generate dichotomies (as can phenetic
> methods) it does not mean that speciation has to be dichotomous. The fact
> that dichotomies are often found may suggest that dicotomous speciation is
> common, or that character relationships are often resolvable to 
> dichotomous
> arrangements - at least in my opinion.
>
> John Grehan
>
>


This is one point I have been thinking about for the past day or so as a 
result of posts on Taxacom.

Generally it is assumed that when a tree has multiple branches arising from 
a single node it must be poorly resolved. However, it occurred to me that it 
is quite possible that several new species could arise simultaneously from a 
single ancestor species.

I can easily envisage that when sea level was lower a single species could 
have inhabited what are now the islands of Indonesia, for example. Rising 
sea levels would then isolate the populations on each island, and over time 
they would speciate, creating a number of different species at the same time 
(not instantaneous of course) from a single ancestor species.

Is there a way to test whether such a node is reliable? I should mention 
that I do not actually run analyses myself; I am more of a traditional 
taxonomist involved in DNA research, partly to ensure that the taxa are 
correctly identified. It is quite possible there is an obvious answer to my 
question, and if so I would be interested to hear it.

Adam.