Homoplasy: A good thread to pull to understand the evolutionary ball of yarn

Feb 24, 2011
Homoplasy is a fascinating and unusual occurrence in evolution. It is the independent acquisition of the same trait in unrelated lineages. To understand whether multiple organisms share the same trait because of homoplasy, their places in the evolutionary tree of life must be defined. Parallelism/convergence homoplasy occurs when the same trait is present in two lineages that lack a recent common ancestor. Reversal homoplasy occurs when a trait is present in an ancestor but not its immediate descendants; but appears later in a subsequent descendant. Credit: Zina Deretsky

With the genetics of so many organisms that have different traits yet to study, and with the techniques for gathering full sets of genetic information from organisms rapidly evolving, the "forest" of evolution can be easily lost to the "trees" of each individual case and detail.

A review paper published this week in Science by David Wake, Marvalee Wake and Chelsea Specht, all currently National Science Foundation grantees, suggests that studying examples of homoplasy can help scientists analyze the overwhelming deluge of genetic data and information that is currently being generated.

For example, studying situations where a derived trait surfaces in two lineages that lack a recent , or situations where an ancestral trait was lost but then reappeared many generations later, may help scientists identify the processes and mechanisms of evolution.

The authors provide many fascinating examples of homoplasy, including different species of salamanders that independently, through evolution, increased their body-length by increasing the lengths of individual vertebrae. By contrast, most species grow longer by adding vertebrae through evolution.

The authors also explain how petals in flowers have evolved on six separate occasions in different plants. A particularly striking example of homoplasy cited by the authors is the evolution of eyes, which evolved many times in different groups of organisms--from invertebrates to mammals--all of which share an identical for their eyes.

These kinds of examples of genetic and help scientists elucidate relationships between organisms, as well as develop a fuller picture of their evolutionary history.

Explore further: Evolution of competitiveness

Related Stories

UCSD Biologists Find New Evidence for One-Way Evolution

Jan 18, 2006

By tracing the 30-million year history of variation in a gene found in plants such as tomatoes and tobacco, biologists at the University of California, San Diego have found new evidence to support an old idea ...

'Evolution: A Developmental Approach'

Jan 27, 2011

What separates humans from Chimpanzees? Is it the genetics of our population, or our different structures and behavior capabilities? To Professor Wallace Arthur it is all of these points, which is why his latest book Evolution: A ...

Reverse evolution in real-time

Jan 11, 2009

Evolutionary biology tells us that replaying life's tape will not not look at all like the original. The outcome of evolution is contingent on everything that came before. Now, scientists at the Instituto Gulbenkian de Ciencia ...

Recommended for you

Evolution of competitiveness

Oct 29, 2014

Virtually all organisms in the living world compete with members of their own species. However, individuals differ strongly in how much they invest into their competitive ability. Some individuals are highly competitive and ...

Status shift for whale pelvic bones

Oct 29, 2014

For decades, scientists assumed that the relatively small pelvic bones found in whales were simple remnants of their land-dwelling past, "useless vestiges" that served no real purpose, akin to the human appendix ...

Is the outcome of evolution predictable?

Oct 28, 2014

If one would rewind the tape of life, would evolution result in the same outcome? The Harvard evolutionary biologist Stephen Jay Gould came up with this famous thought experiment. He suggested that evolution would not repeat ...

How did complex life evolve? The answer could be inside out

Oct 27, 2014

A new idea about the origin of complex life turns current theories inside out. In the open access journal BMC Biology, cousins Buzz and David Baum explain their 'inside-out' theory of how eukaryotic cells, which all multic ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.