Migration: Micro and Macro

Biology and history both tell us that life began with migration: from cells to sharks, hummingbirds to human beings, life migrates for three reasons—survival, protection, and reproduction. 

By | June 1, 2012

Chatto & Windus, January 2012" > Chatto & Windus, January 2012


Living organisms are in motion all the time. Cells migrate in bodies; bird migration is the constant heartbeat of the planet; displaced migrants stream across the globe in search of new homes. In my new book, The Mara Crossing—named after Kenya’s Mara River, the last obstacle surmounted by wildebeest after their annual 3-month trek north for new grass—I explore parallel migrations in microbiology, animal behavior, and human history. Ever since the first self-replicating cells arrived on Earth (coming maybe from deep in the sea or from outer space, or called into being by biochemical accident), life spread in that first form of migration, permanent dispersal.

When organisms arrive in new environments they are transformed by them; but more importantly they also transform them. When the first cells of blue-green algae dispersed, they oxygenated Earth’s atmosphere, enabling the evolution and dispersal of more and more complex life-forms, such as the first large land migrant, the primeval tree Archaeopteris, which created oxygen-producing forests. By such migrations, Earth became a place where animals could breath.

But meanwhile, following the same principle of constant movement, cells were simultaneously moving within these new life-forms. In living bodies atoms move in molecules, molecules transit through cells, and cells migrate through tissue, pushing forward protrusions and tucking their trailing ends behind them. Cells in our bodies normally migrate for two reasons: to create new life, aiding embryonic development, or to repair and defend the organism. Cell migration is the basis of active immunity. Guided by chemicals they detect in their environment, immune cells gather at sites of infection to do battle.

At the macro level, larger life-forms are also continually on the move. As the tilted globe rotates, temperatures drop in different places and food vanishes. Hundreds of life-forms react to seasonal change by migrating, in order to feed, survive, and reproduce.

All good systems, however, can go wrong. Four billion years ago, some genes began to spread by tricking other genes into helping them replicate. Parasites and viruses replicate their own DNA by hijacking the machinery of their hosts’ cells. So diseases travelled with their hosts. Malaria migrated with us out of Africa. Plasmodium parasites, the microbes that cause malaria, behave like computer hackers—always ahead of the game, always changing, developing resistance to chemicals we throw at them. As Charles Darwin pointed out, nature’s forms do not demonstrate benevolence, divine or otherwise.

Within a single organism, cellular migration can create similar mayhem. Migrating cells cause developmental disorders like cardiovascular disease, and above all they characterize metastatic cancer. Like other life-forms, cells that have turned cancerous aim to survive, protect themselves, and reproduce. And so they migrate. They move in the same way as other cells, pushing forward their leading edge, travelling away from primary tumors to invade normal tissue.

Recent research has discovered that cancerous cells prepare for metastatic travel by gathering proteins near their leading edges. This strategy is interestingly parallel to that of songbirds, which suddenly step up their feeding before migration and in a few weeks double their weight. Cancerous cells also engage a “chaperone” protein to help them move what they need to their front edge, and this too is oddly similar to the pre-journey biochemical boost that insect-eating songbirds give themselves by switching to a diet of fruits rich in antioxidants.

“Migrate” comes from Latin migrare, “to move from one place to another.” It is related etymologically to Greek ameibein, “to change,” and English “mutable.” This new research may discover ways to prevent the movement of tumor cells by stopping them from gathering the proteins they apparently need to travel. The more we study ways in which different biological entities organize their oddly similar journeys—whether macro or micro, cellular, ornithological, or human—the more insight we have into the restlessness of all life: how life needs, perpetually, not only to move but to change.

Ruth Padel is an award-winning British poet and writer. She is Fellow of the Royal Society of Literature, a Fellow and Council Member of the Zoological Society of London, and a great-great-granddaughter of Charles Darwin. Read an excerpt from her new book The Mara Crossing

Add a Comment

Avatar of: You



Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo


Avatar of: Guest


June 1, 2012

There is not a sharp line between living things and inanimate things.  There is a gray area.  Among biologists themselves, there are differences of opinion as to what criteria to include, in classifying as to which side of the line between animate and non animate certain things fall.  And precisely because of this, it strikes me as hilarious to overhear anyone, who holds himself or herself out to be scientifically literate, arguing with anyone over what life "is."  (A similarly ridiculous thing to argue about is what a word "means."  Even a discussion of the meaning of the word "science" can begin with some easily agreed-upon characteristics, but thence fades off into a gray area at the outer edges.  Discussions of what the clashes of perceptions of its meanings are is most certainly not a waste of time.  However, for two persons, each over the age of twelve years to argue over which subsumptive relations MUST be included, in drawing a clear  line between what is non science and what is science indicates ignorance of how words are derived, how they change over time, the limitations of language itself to be precise outside a realm such as mathematics, where BY COMMON AGREEMENT the meaning of a concept such as the union of sets is agreed upon.

That's the key, don't you see, things are what they be, only insofar as we agree.  (: >)

How interesting it is that dispersion occurs broadly in nature, among things we tend to perceive to be animate and, also, among things we tend to perceive to be inanimate.  But is there not a gray area between migration of living things and dispersion of non-living things. 

Hopefully the author of this article will agree when I say that -- for purposes of science -- broadly and simplistically designated as being man's study of nature, there is little to be gained, more than as a literary exercise, in arguing whether the "migrations" of cancer cells, physiologically, shares a strong kinship with, say, migration of Mexican laborers to the United States.  Yes, there are some similarities.  But, also, there are some differences. 

Now if one has an agenda -- such as, for example, a desire to plant the suggestion of philosophical materialism as ruling all things in nature, including the origin(s) of life and of speciation, without scientifically ruling it in as a certainty, nor ruling it out as a certainty -- that could be entertaining.  Now, PLEASE, my point is not to accuse the author of such a motive; it is only to suggest that pointing to correlations between what cancer cells "do" and what it "means," in the context of how nature has done what it has done, and is doing what nature does, is thought provoking and entertaining... but one of the most important goals of "science" (I think) is to avoid rushing into fixing upon such a word as "migration" more than the poor word may usefully contain. 

If you are a scientist, involved in research, would you not agree that much of the highest and best of the products of "good" science is to DISAMBIGUATE, rather than ambiguate?  If you agree, then possibly you will agree that it might be useful and even perhaps enlightening to generalize about things that disperse (or in that sense, only, share in what is a broad sense of dispersion).

We could, perhaps even more appropriately, refer to metastasis as "colonization."  The subsumptive relations whereby the word metastasis and the word colonization might be mulled together, share more veritable docking points for comparison, do they not.

Both colonization and migration tend to be associated with COGNITIVE DECISION-MAKING by the migrant or colonizer. 

Often, in my reading of papers and articles about biological subjects I perceive what to me me seems like a very odd conflict of viewpoint.  On the one hand, the writing will be slanted in such a way as to suggest that all things are material (actually, without change and motion, material would be in an eternally fixed position, and time would be meaningless, so a better term for what is insinuated might be termed materialistic dynamism."  Even human cognition is explained (explained away?) within this materialist dynamism view.  It's all just matter, moving about in weird ways.

But, notice what I am about to point out, in your own reading and/or writing:  Is there not much innuendo, whereby it is suggested that even brainless biota have a will?  Seriously.  If you LOOK FOR IT you will see hundreds of statements caged in such a way as to SUGGEST that a species develops a certain characteristic because its environment rewards it for doing so -- because it is the pragmatically appropriate, or advantageous thing to do.

Do you see it?

Many, many slantings of writing in and about the sciences, first take away at one level of perception what they then give back to another level.  Nature is portrayed, on the one hand as being nothing more than material dynamism, and then is assigned at the local and particular level, of, say, a molecule, a virus, a cell, a plant, an amoeba... none of which have any cerebrum wherewith to express conscious reasoning or decision-making... and then are attributed with doing something appropriately beneficial for self, as though by way of "reading" its environment, envisioning a solution to a need, and then proactively interacting in a self-serving way.

Let me emphasize that I do, indeed, perceive that there are epigenetic (or sub-epigenetic?) mechanisms at work whereby some kind of "availing itself of opportunity" DOES take place... HAS TO take place... for bio-evolution to occur, if it occurs by way of "availance" by an organism of opportunities, and avoidance of mishaps. If so, then those self-honest in the sciences will have no reluctance to see that these mechanisms are as yet undiscovered. And the benefits of discovering them -- if and when it occurs -- will take the study of biology far beyond its current ability to UTILIZE such knowledge in such a way as to prevent or correct birth defects, cancers, pathologies of all sorts. Eugenics by way of FIXING members of a population, both somatically and gametically (rather than by killing off misfits) would give eugenics a whole new, improved image, wouldn't it.

For all we know, maybe cancer cells do "read" their environment, contemplate what would advance the cause of their unlimited propagation, forming a colonization plan to invade other parts of an organism, gather up resources for the journey, and then implement the plan.

Prosaic, is it not?

But in science, we look for mechanisms, I submit, not prose. And we try to avoid personifications of mindless, living or non-living things (or establish which ones do, indeed, think, plan and act in opportunistic ways), rather than amuse ourselves with clever, entertaining, conceptual homologues, do we not?

Avatar of: Roy Niles

Roy Niles

Posts: 32

June 2, 2012

All structures that approach the biological forms of living are at least minimally aware of an ever changing environment and over time will learn to anticipate the varieties of probable changes to be faced and preadapt their necessarily acquired survival responses accordingly.

Avatar of: Dov Henis

Dov Henis

Posts: 1457

June 2, 2012

Natural survival is universally ubiquitous, for ALL mass formats.

"Life migrates for three reasons". The three reasons are one reason : survival.

Life is just another mass format.

Dov Henis
(comments from 22nd century)

Popular Now

  1. Thousands of Mutations Accumulate in the Human Brain Over a Lifetime
  2. Two Dozen House Republicans Do an About-Face on Tuition Tax
  3. Putative Gay Genes Identified, Questioned
    The Nutshell Putative Gay Genes Identified, Questioned

    A genomic interrogation of homosexuality turns up speculative links between genetic elements and sexual orientation, but researchers say the study is too small to be significant. 

  4. Can Young Stem Cells Make Older People Stronger?