Quantifying passive and driven large-scale evolutionary trends.

نویسنده

  • S C Wang
چکیده

I introduce a new statistical method, analysis of skewness, for quantifying large-scale evolutionary trends as a combination of both passive and driven trends. My approach is based on the skewness of subclades within a parent clade. I partition the total skewness of the parent clade into three components: (1) skewness between subclades; (2) skewness within subclades; and (3) skewness due to changes in variance among subclades. The third component corresponds to a new type of passive trend, in which overall skewness of a parent clade is due to greater variability in subclades to the right of the mean. Using this partitioning, I decompose an observed trend into two components: a driven portion and a passive portion. thus quantifying the effect of small-scale dynamics on large-scale behavior of clades. Applications are given to Miocene-Pliocene rodent size and Ordovician brachiopod muscle geometry.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

MATTERS OF THE RECORD Accounting for unequal variances in evolutionary trend mechanisms

Evolutionary trends seemingly abound throughout the history of life. Perhaps the best-known example is Cope's rule, the tendency for lineages to increase in size over time. Other examples include hypothesized trends toward increasing complexity and fitness. What kinds of mechanisms cause such large-scale trends—trends occurring in higher taxa over geological time spans—and how can we effectivel...

متن کامل

Passive and Driven Trends in the Evolution of Complexity

The nature and source of evolutionary trends in complexity is difficult to assess from the fossil record, and the driven vs. passive nature of such trends has been debated for decades. There are also questions about how effectively artificial life software can evolve increasing levels of complexity. We extend our previous work demonstrating an evolutionary increase in an information theoretic m...

متن کامل

A partition-based algorithm for clustering large-scale software systems

Clustering techniques are used to extract the structure of software for understanding, maintaining, and refactoring. In the literature, most of the proposed approaches for software clustering are divided into hierarchical algorithms and search-based techniques. In the former, clustering is a process of merging (splitting) similar (non-similar) clusters. These techniques suffered from the drawba...

متن کامل

Multi-objective Optimization of a Solar Driven Combined Power and Refrigeration System Using Two Evolutionary Algorithms Based on Exergoeconomic Concept

This paper deals with a multi-objective optimization of a novel micro solar driven combined power and ejector refrigeration system (CPER). The system combines an organic Rankine cycle (ORC) with an ejector refrigeration cycle to generate electricity and cold capacity simultaneously. Major thermodynamic parameters, namely turbine inlet temperature, turbine inlet pressure, turbine back pressure, ...

متن کامل

A Comparison of Evolutionary Activity in Artiicial Evolving Systems and in the Biosphere

Bedau and Packard 7] devised an approach to quantifying the adaptive phenomena in artiicial systems. We use this approach to deene two statistics: cumulative evolutionary activity and mean cumulative evolutionary activity. Then we measure the dynamics of cumulative evolutionary activity, mean cumulative evolutionary activity and diversity, on an evolutionary time scale, in two artiicial systems...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Evolution; international journal of organic evolution

دوره 55 5  شماره 

صفحات  -

تاریخ انتشار 2001