Reasons to Believe

Repeated Origin of Multicellularity Points to a Creator

The church isn’t a building; it’s a community made up of people who trust in Christ’s work on the cross for their salvation and follow His teachings.

The apostle Paul compares the church to an organism. The congregation is made up of individuals with specific gifts and abilities who, ideally, exercise their talents for the benefit of all. In this way, the church is a body—the body of Christ.

In a similar way, some of the organisms most familiar to us (such as animals, plants, and fungi) are multicellular, consisting of a vast number of individual cells, each with specialized capabilities that contribute to the structure and operation of the organism as a whole.

Scientists want to understand how multicellularity evolved. Recent work on the origin of multicellularity in brown algae (seaweed and kelp) sheds some light on the matter.1 The work indicates that multicellularity arose separately and independently in brown algae, plants, and animals. The repeated, independent origins of multicellularity raise questions about the evolutionary paradigm and at the same time evince the work of a Creator.

The Origin of Multicellularity

From an evolutionary perspective, support for the transition from unicellular (single cell) to multicellular organisms requires the emergence of several novel biochemical systems. Such systems include:

  • pathways that transform cells from generalized to specialized forms during growth and development;
  • mechanisms for the migration of cells relative to each other during growth and development;
  • structures that support cell-cell adhesions;
  • and mechanisms for cell-cell communication.

All of these systems have to be in place and operate in an integrated fashion to support multicellularity.

The Origin of Multicellularity in Brown Algae

To gain understanding about how multicellularity originated in brown algae, a research consortium sequenced the entire genome (consisting of 214 million genetic letters) of the brown algae Ectocarpus siliculosus. They then compared it to closely related unicellular organisms. The research team noticed that multicellularity’s origin in the brown algae appears to correlate with the appearance of a rich ensemble of genes that encode proteins involved in signal transduction (processes that support cell-cell communication).

They also noted that this same collection of genes also correlates with the advent of multicellularity in plants and animals. According to the evolutionary paradigm, multicellularity arose independently in brown algae, plants, and animals. And the same biochemical systems that make multicellularity possible also appear to have arisen in each group of organisms on three separate occasions.

Implications for the Evolutionary Paradigm

Evolutionary processes are blind and undirected. Their very essence renders evolutionary outcomes unpredictable and nonrepeatable. According to the concept of historical contingency, espoused by late scientist Stephen Jay Gould in his book Wonderful Life, chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of a historical sequence of chance genetic changes operated on by natural selection, which also consists of chance components. Thus, if evolutionary events could be “rewound” and “replayed,” the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs would appear repeatedly throughout nature among unrelated organisms.

Yet it looks as if evolution has repeated itself, time and time again! Evolutionary biologists note that evolutionary processes frequently seem to converge independently on identical anatomical, physiological, behavioral, and biochemical systems. (As a case on point, go here and here to see two articles I wrote on this phenomenon some time ago.) Evolutionary biologists refer to repeated evolutionary outcomes as convergence.

In my book The Cell’s Design I document over one hundred examples of convergence at the biochemical level. On this basis I argue that if historical contingency truly reflects the nature of evolutionary processes, then the widespread occurrence of a broad range of biochemical systems emerging repeatedly raises significant questions about the validity of evolutionary explanations for life’s origin and diversity.

The repeated origin of multicellularity in brown algae, plants, and animals defies an evolutionary explanation, particularly since it involves the independent origin of virtually the same biochemical systems. But this new insight makes sense if a Creator responsible for the multi-member church was also responsible for assembling multicellular life-forms.

Subjects: Convergence

Dr. Fazale Rana

In 1999, I left my position in R&D at a Fortune 500 company to join Reasons to Believe because I felt the most important thing I could do as a scientist is to communicate to skeptics and believers alike the powerful scientific evidence—evidence that is being uncovered day after day—for God’s existence and the reliability of Scripture. Read more about Dr. Fazale Rana

Endnotes:

1. J. Mark Cock et al., “The Ectocarpus Genome and the Independent Evolution of Multicellularity in Brown Algae,” Nature 465 (June 3, 2010): 617–21.