What is an individual (Part 2): An arbitrary definition

Last week I discussed why defining the individual is so difficult. Having put you in an existential crisis over whether or not you are an individual, it is time to pick up the pieces and see if we can come up with a useful phenotypically based definition of an individual. At the very least perhaps […]

What is an individual (Part 1)

It seems to me that the bad-boy question of evolution that sneaks around the edges, and nobody seems to notice is what is an individual? Think about it: My definition of evolution is change in the distribution of a population due to the gain or loss of individuals. I use “individuals” as if that were […]

Speciation in continuous populations

I am in Brazil this week to give a talk about speciation in continuous populations, so I figure I will save a little effort by summarizing some of the stuff that is in that talk. By the way, Sao Carlos is a wonderful town, and if you can come up with an excuse to come […]

Wright’s Shifting Balance Process revisited one last time

It is shaping up to a busy summer, mostly because I am packing up my house so I can go to Brazil for a year. And that is my rather lame excuse for neglecting my blog. In any case, what I did so many weeks ago was go through the three phases of Wright’s shifting […]

Wright’s Shifting Balance Process: Phase 3 part 2

Last week I tried to establish that group selection by differential migration can work.   On both experimental and theoretical grounds we find it does work, and in fact will frequently be stronger than individual selection. The question comes where does it fit into Wright’s shifting balance process. The first problem we need to confront is […]

Phase 3: Group selection by differential migration

Having taken a week off (blame it on Jason Wolf – he is the one who gave me a writing assignment!) it is time to get back to it. This week we turn to the final phase of Wright’s shifting balance process, phase three the phase of interdeme selection. In Wright’s view populations centered on […]

The Phase of Mass Selection and Long Term Selection Experiments

On to Phase 2 of Wright’s Shifting Balance Process. But before I do I should probably start with a shameless attempt to up my standings in the next Carnival of Evolution World Cup Competition by alerting the committee responsible to the following figure that I found: Obvious evidence of Pre-Cambrian Bunnies (unapologetically lifted from http://clubschadenfreude.com/2013/02/19/not-so-polite-dinner-conversation-part-9-the-second-half-of-19-limestone-coelacanths-and-circular-reasoning/) […]

Was Fisher (W)right?

Once again without internet, thundering my way north on the Silver Star. It is hard to keep focus on what I intended on the subject I am writing on. The Evolution meetings were inspiring to say the least. Lots of great talks, many of which I could easily write a blog about, but I must […]

The 1984 founder event debate: Its relation to Phase 1 of Wright’s Shifting Balance Process

Today I am speeding south on the Empire State in the morning and the Silver Star in the afternoon. I should be in Raleigh Durham for the Evolution meetings late this evening. For the uninitiated Amtrak trains have names that reflect where they are going. Thus, the famous Steve Goodman/Arlo Guthrie song, “City of New […]

Wright’s Shifting Balance Process

Now that I have talked about how Wright thought evolution didn’t occur on adaptive landscapes, now it is time to talk about how he thought it did occur. The 7 assumptions and the adaptive topography were all basically background for his “shifting balance” process of evolution (Wright 1977 Evolution and Genetics of Populations. Vol. III. […]